BACKGROUND

[0001] Treating water to produce potable water (e.g. water drinkable by humans such that the humans do not get sick) may be challenging in some environments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Reference will now be made, by way of example only, to the accompanying drawings in which:

[0003] FIG. 1 is a schematic diagram of an example device to mix liquid in microchambers.

[0004] FIG. 2A is a schematic diagram of an example microchamber.

[0005] FIG. 2B is a schematic diagram of top view of the microchambers of the device of FIG. 1 .

[0006] FIG. 3 is a schematic diagram of an example device with a valve and thermal ejector mixing components powered by a photovoltaic power source.

[0007] FIG. 4 is a schematic diagram of an example device with thermal inkjet mixing components and thermal ejector pumps powered by a photovoltaic power source.

[0008] FIG. 5 is a schematic perspective view of an example device with eight polarized microchambers.

[0009] FIG. 6 is a schematic perspective view of an example device including stages of microchambers joined by structural components.

[0010] FIG. 7A is a schematic diagram showing a portion of stages of microchambers joined by structural components provided in the form of micro twisting layers. [0011] FIG. 7B is a schematic exploded view of the micro-twisting layers of a structural component of FIG. 7A.

[0012] FIG. 7C is a schematic representation of particles of contaminants being twisted by the micro-twisting layers of the structural components of FIG. 7A.

[0013] FIG. 8 is a schematic diagram showing a mixing component in the form of a microfluidic network of micropipes.

[0014] FIG. 9A is a schematic diagram showing a portion of the microfluidic network of micropipes of FIG. 8 combined with conductive layers that include thermal ejector.

[0015] FIG. 9B is a schematic diagram showing an example conductive layer that includes thermal ejector.

[0016] FIG. 9C is a schematic diagram showing an example conductive layer that includes thermal ejector on one side.

[0017] FIG. 9D is a schematic diagram showing an example conductive layer that includes thermal ejector on a side opposite to that of the example conductive layer of FIG. 9C.

DETAILED DESCRIPTION

[0018] Treating water to produce potable water (e.g. water drinkable by humans such that the humans do not get sick) may be challenging in some environments. For example, globally, at least 2 billion people consume contaminated drinking water due to lack of any source of potable water, which may result in diseases such as diarrhea, cholera, dysentery, typhoid, and polio. By 2025, half of the world’s population is expected to be living in water-stressed areas. In least developed countries, 22% of health care facilities have no water service, 21% have no sanitation service, and 22% have no waste management service. Furthermore, most least developed countries lack sufficient income to afford water cleaner systems or services. While not as acute, finding potable water in other situations, such as camping, may also be challenging.

[0019] In some examples, devices may be used to expose water to ultraviolet (UV) light, which may destroy contaminants and/or biological contaminants in the water to render the water as potable. However, the efficiency of such devices may depend on maximizing exposure of the water to the ultraviolet light. In particular, microchambers may be used to generate laminar flows of water between an inlet and an outlet of a device, and UV light may be exposed to at least edges of the microchambers. As understood herein, microchambers may comprise laminar-shaped microfluidic flows, of sizes described in more detail below. Such microchambers may be used to control flow of the water between the inlet and the outlet and/or to assist with maximizing exposure of contaminants in the water to the UV light. However, in such microchambers, flow of water tends to be parabolic between the inlet and the outlet, such that flow of water is slower at the edges of the microchambers and faster towards a center of microchambers, and furthermore flow of the water between the edges does not occur and/or is minimal as compared to flow between the inlet and the outlet. As such, contaminants in water at a center of a microchamber may be exposed to less UV light than contaminants in water at the edges, which may reduce the efficacy of the UV light in destroying contaminants in the water. [0020] As such, provided herein is a device which has an inlet and an outlet, and microchambers therebetween which receive liquid from the inlet and form laminar microflows of the liquid. The liquid may be water and/or any other suitable liquid and/or UV-transparent liquid. A light source of the device exposes the laminar microflows of the liquid in the microchambers to ultraviolet light, the light source located, for example, at the edges of the microchambers.

[0021] Herein, reference will be made to thermal ejectors, thermal ejector pumps, thermal ejector mixers, thermal ejector push pump-mixers, and the like. In particular, such component are understood to be similar to thermal inkjet devices used in thermal inkjet printers, and the like, but used to pump and/or mix liquids other than ink, such as water, and the like. Such thermal ejectors, thermal ejector pumps, thermal ejector mixers, thermal ejector push pump- mixers, and the like, are hence understood to include resistors in microchannels, which are controlled to generate heat, which vaporizes liquid in a microchannel to generate bubble. As the bubble expands, liquid that is not vaporized is pushed and/or ejected by the bubble out of microchannel. When the bubble pops and/or collapses, a vacuum is created which pulls more liquid into an end of the microchannel opposite to the end where the liquid is ejected. As such, it is understood that a resistor of a thermal ejector, thermal ejector pump, thermal ejector mixer, thermal ejector push pump-mixers, and the like, is located asymmetrically in a microchannel, for example closer to an end of the microchannel that pulls liquid into the microchannel and further away from an opposite end of the microchannel where the liquid is ejected. Regardless, the ejection of the liquid may result in mixing of the liquid, for example when a plurality of thermal ejectors are used to respectively pull liquid therein and eject the liquid, for example in different directions. Similarly, ejection of the liquid may result in pumping of the liquid. Hence, while the terms thermal ejectors, thermal ejector pumps, thermal ejector mixers, thermal ejector push pump-mixers, and the like, are used herein, it is understood that such components may function using the same underlying technology, and different terms may be used to describe such components based on the respective function thereof. However such terms are not unduly limiting. For example, a thermal ejector mixer, which may mix liquid, is also understood to pump liquid. Similarly, a thermal ejector pump may also mix liquid. Similarly, a thermal ejector push pump-mixer may both pump a liquid (e.g. by pushing a liquid, as described above) and mix a liquid.

[0022] However, to randomize flow of liquid in the microchambers and/or break parabolic flow of liquid in the microchambers, the device further comprises mixing components to mix the liquid of the laminar microflows in the microchambers. In some examples, such mixing components may be provided in the form of thermal ejectors in any suitable location in the device, and in any suitable configuration. For example, the thermal ejectors are understood to include microchannels located between the inlet and the microchambers to direct the liquid in various directions into the microchambers.

[0023] Alternatively, such mixing components may be provided in the form of micro-twisting layers within the microchambers to passively twist or shift the liquid within the microchambers. For example, such micro-twisting layers may include respective apertures which are aligned with each other but at different angles which result in the liquid, and more specifically contaminants in the liquid, between twisted or shifted as the liquid passes through the micro-twisting layers. In some examples, a laminar flow in the microchambers may occur via two, or more than two, microchambers arranged such that a laminar flow exits a respective outlet of a first microchamber and enters a respective inlet of a second microchamber, with the micro-twisting layers located between the two microchambers. Put another way, a microchamber may be formed from sub microchambers arranged such that a laminar flow of the microchamber exits a respective outlet of a first sub-microchamber and enters a respective inlet of a second sub-microchamber, with the micro-twisting layers passively twisting or shifting the liquid within the microchamber.

[0024] Alternatively, such mixing components may be provided in the form of a microfluidic network of microfluidic pipes located within the microchambers or connecting microchambers (and/or sub-microchambers), with the microfluidic pipes arranged to move and/or shift liquid in the microchambers (e.g. to move liquid from an edge to a center, or vice versa). In some examples, the microfluidic network may include thermal ejectors to pump the liquid through the microfluidic pipes. In some examples, the aforementioned micro-twisting layers may be provided in combination with the microfluidic network.

[0025] A first aspect of the present specification provides a device comprising: an inlet to receive liquid; microchambers to receive the liquid from the inlet and form laminar microflows of the liquid; a light source to expose the laminar microflows of the liquid in the microchambers to ultraviolet light; mixing components to mix the liquid of the laminar microflows in the microchambers; and an outlet to recombine the laminar microflows of the liquid from the microchambers.

[0026] At the device of the first aspect, the mixing components may comprise thermal ejectors.

[0027] The device of the first aspect may further comprise thermal ejector pumps to move the liquid through the microchambers, and the mixing components may comprise thermal ejector mixers, which may be located between the inlet and the microchambers.

[0028] At the device of the first aspect, the mixing components may comprise thermal ejector push pump-mixers located between the inlet and the microchambers.

[0029] The device of the first aspect may further comprise alternately polarized microchambers walls.

[0030] At the device of the first aspect, the mixing components may comprise micro-twisting layers within the microchambers, the micro-twisting layers to passively twist or shift the liquid within the microchambers. [0031] At the device of the first aspect, the mixing components may comprise a microfluidic network of microfluidic pipes located within the microchambers or connecting the microchambers.

[0032] At the device of the first aspect, the mixing components may comprise a microfluidic network of microfluidic pipes, the microfluidic pipes located within the microchambers or the microfluidic pipes connecting the microchambers, the microfluidic network further comprising thermal ejectors to pump the liquid through the microfluidic pipes.

[0033] At the device of the first aspect, the mixing components may comprise a microfluidic network of microfluidic pipes, the microfluidic pipes located within the microchambers or the microfluidic pipes connecting the microchambers, the microfluidic network or walls of the microfluidic network being nano-porous, conductive, UV reflective or UV transparent.

[0034] The device of the first aspect may further comprise a valve located at the inlet, the valve to prevent flow of the liquid into the microchambers when the ultraviolet light is below a threshold intensity.

[0035] The device of the first aspect may further comprise a photovoltaic power source to power the light source or the mixing components or to polarize microchambers walls.

[0036] The device of the first aspect may further comprise: thermal ejector pumps to move the liquid through the microchambers; and a photovoltaic power source for powering the light source and the thermal ejector pumps, wherein a rate of pumping of the liquid by the thermal ejector pumps increases as power from the photovoltaic power source increases, and intensity of the ultraviolet light produced by the light source increases as the power from the photovoltaic power source increases.

[0037] At the device of the first aspect, the microchambers have channel heights dimensions in a range of about 300pm to about 1 mm, or in a range of about 300mih to about 500pm, and the microchambers have channel widths in range of about 1 cm to about 2 cm.

[0038] A second aspect of the present specification provides method comprising: receiving liquid at an inlet of a device; dividing the liquid into microchambers of the device forming laminar flows of the liquid; exposing the laminar microflows of the liquid in the microchambers to ultraviolet light provided by a light source of the device; mixing the liquid in the laminar microflows of the microchambers using mixing components of the device to randomize flow of liquid in the microchambers or break parabolic flow of liquid in the microchambers; and recombining the laminar microflows of the liquid from the microchambers at an outlet of the device.

[0039] The method of the second aspect may further comprise regulating flow of the liquid into the microchambers based on an intensity of the ultraviolet light, using a valve of the device or thermal ejector pumps of the device.

[0040] FIG. 1 shows a schematic diagram of an example device 100 to mix liquid in microchambers. The device 100 comprises a housing 105 having an inlet 110 and outlet 112. The inlet 110 and the outlet 112 may be respectively threaded to attach to respective bottles and/or containers, and the like. For example, as depicted, the inlet 110 may be threaded to receive the neck of a bottle 114 (partially depicted with broken lines), and the like, which may comprise a glass or plastic (e.g. polyethylene terephthalate (PET)) bottle which may contain contaminated water and/or liquid (see below). Similarly, the outlet 112 may be threaded to receive the neck of a bottle 116 (partially depicted with broken lines), and the like, which may comprise a glass or plastic (e.g. PET) bottle. The bottle 116 may be “clean” and/or sterilized and/or otherwise free of contaminants.

[0041] Hereafter, the device 100 will be described with respect to a liquid which may include water and/or any other suitable liquid that is UV transparent. In particular, the term “UV transparent” as used herein may be understood to mean that a medium through which UV light is travelling, such as water or any other suitable liquid (and/or a window, as described below), does not generally absorb such UV light and/or absorbs only small amounts of such UV light, such as less than 10% and/or less than 1% and/or less than 0.1 % of such UV light. Ranges of UV light for which water and/or liquid and/or other components described herein may be transparent are described in further detail below.

[0042] Furthermore, such liquid (e.g. which may be in the bottle 114) may initially be contaminated with contaminants, such as biological contaminants, which, when ingested by a human, may cause the human to become sick. Such contaminants may include bacteria, viruses, and the like, and/or any other contaminant which may be rendered unharmful to humans by UV light. Indeed, as will be described in more detail below, the device 100 may be to render a liquid, such as water, potable and/or drinkable by humans, for example as liquid flows from the bottle 114, through the device 100, and to the bottle 116. As such, a clean and/or sterilized bottle, such as the bottle 116, is understood to be free of contaminants to receive liquid rendered potable by the device 100.

[0043] However, while the device 100 is described with respect to being attachable to the bottles 114, 116, the device 100 may be attachable to any suitable containers such that a contaminated liquid may flow from one container, and/or into the device 100 via the inlet 110, and to another container, and/or out of the device 100 via the outlet 112. In some examples, liquid may therefore flow under gravity feed from the bottle 114, through the device 100, to the bottle 116. A pipe (not shown) may be optionally inserted between the bottle 114 and the inlet 110 to increase the flow under gravity.

[0044] Hence, in general, the inlet 110 is to receive liquid, such as water and/or any other suitable liquid that is UV transparent. Example flow of liquid in the device 100 is generally shown via arrows 113.

[0045] The device 100 further comprises, a plurality of microfluidic chambers 120 between the inlet 110 and the outlet 112, the plurality of microfluidic chambers referred to herein as microchambers 120. The microchambers 120 are generally to receive the liquid from the inlet 110 and form laminar microflows of the liquid. For example the microchambers 120 may be further to divide the water from the inlet 110 into a plurality of laminar microflows; however, the device 100 may include other features to divide the liquid into laminar microflows, such as various physical dividers 122 forming channels, and the like, to direct the liquid to the microchambers 120; as depicted, the microchambers 120 are understood to be formed by walls 124 therebetween. The size and shape of the microchambers 120 are described below; however, in particular, the microchambers 120 may generally comprise microfluidic devices through fluid flows in micrometer-scale channels, and the like.

[0046] The device 100 further comprises a light source 125 to expose the laminar microflows of the liquid in the microchambers 120 to UV light. As depicted, the light source 125 is provided in two portions, on opposite sides of the device and/or the microchambers 120, however the light source 125 may be provided in any suitable configuration. In general, the UV light provided by the light source 125 may be to kill and/or neutralize contaminants, such as bacteria, in the liquid and/or render such contaminants to be not harmful to humans. For example, the UV light provided by the light source 125 may ionize biological contaminants thereby killing and/or neutralize such biological contaminants.

[0047] The device 100 further comprises mixing components to mix the liquid of the laminar microflows in the microchambers 120, for example to randomize flow of the liquid in the microchambers 120 or break parabolic flow of the liquid in the microchambers 120. Various examples of mixing components are described herein, however in FIG. 1 , the device 100 comprises mixing components 130 in the form of thermal ejectors (e.g. the mixing components of the device 100 may comprise thermal ejectors of any suitable type). While in FIG. 1 , thermal ejectors of the mixing components 130 are depicted without microchannels, it is understood that such thermal ejectors of the mixing components include resistors inside microchannels as described below with respect to FIG. 2A. It is understood that thermal ejectors of the mixing components 130 generally function by pulling liquid therein (e.g. from a direction of the inlet 110) and form vapor jets of the liquid in a random and/or non- parabolic manner such that flow of the liquid in the microchambers 120 is randomized and/or parabolic flow of liquid in the microchambers 120 is broken.

[0048] As depicted in FIG. 1 , the thermal ejectors of the mixing components 130 may generally perform mixing functionality. Furthermore, the thermal ejectors of the mixing components 130 may be angled with respect to the microchambers 120 to better disperse contaminants therein. Furthermore, in FIG. 1 , flow of liquid within the microchambers 120 may generally occurs due to gravity, with the thermal ejectors of the mixing components 130 dispersing the contaminants in the liquid, such that the contaminants therein are dispersed in a random and/or non-parabolic manner. In other examples, the thermal ejectors of the mixing components 130 may be further adapted to push the liquid from the inlet 110 towards the microchambers 120, as well as mix the liquid as next described with respect to FIG. 2A.

[0049] As best seen in FIG. 2A, described below, such mixing of the liquid in the microchambers 120, caused by the thermal ejectors of the mixing components 130 may cause contaminants at the edges of a microchamber 120, and/or closer to the light source 125, to move towards the center of a microchamber 120, and further cause contaminants at the center of a microchamber 120 to move towards the edges of a microchamber 120 and/or closer to the light source 125. As such, the mixing may cause contaminants distributed throughout the liquid to have similar exposure to UV light of the light source 125; without such mixing, contaminants in the center of a microchamber 120 may not move towards the edges of a microchamber 120 due to parabolic flow and hence may experience less exposure to the light source 125, reducing the possibility of the UV light neutralizing such contaminants.

[0050] As depicted, the thermal ejectors of the mixing components 130 are located between the inlet 110 and the microchambers 120. However, the thermal ejectors of the mixing components 130 may be in any suitable location.

[0051] Furthermore, it is understood that, the microchambers 120 depicted in FIG. 1 are shown in an end view, to show that the microchambers 120, formed by the walls 124, may be about parallel. Furthermore, while the locations of the light source 125 in FIG. 1 are depicted about parallel to the microchambers 120, the light source 125 may be positioned about perpendicular to planes formed by the microchambers 120. In particular, locations of the light source 125 may be better understood from FIG. 2A and FIG. 6 described in more detail below.

[0052] Attention is next directed to FIG. 2A which shows one example microchamber 120 in an orientation that is about 90° to that depicted in FIG. 1. For example, the example microchamber 120 is rectangular and/or square in shape, with a depth defined by a distance between the walls 124 (e.g. a distance between the walls 124 best seen in FIG. 2A), which, in FIG. 2A, are understood to be above and below a plane of the microchamber 120. As such, liquid flowing into the example microchamber 120, as indicated by arrows 132, for example from the inlet 110 (not depicted in FIG. 2A but nonetheless understood to be present), is formed into a sheet by the microchamber 120 and/or flows laminarly in the plane of the microchamber 120, which is understood to be a laminar flow. In particular, the liquid is understood to enter the example microchamber 120 at an edge 134 and exit the example microchamber 120 at an opposing edge 135.

[0053] Furthermore, as depicted in FIG. 2A, the locations of the light source 125 are understood to be at edges 136 of the plane of the example microchamber 120 that, as depicted, are about perpendicular to the edges 134, 135. UV light 137 from the light source 125 (e.g. represented by dashed arrows) hence enters the example microchamber 120 from the edges 136, and may be directed towards a center 138 of the example microchamber 120. However, as the UV light 137 may be absorbed by contaminants in the liquid that are closer to the edges 136, the UV light 137 at the center 138 may be less intense than at the edges 136 and hence less effective at neutralizing contaminants in the liquid at the center 138.

[0054] As such, the thermal ejectors of the mixing components 130 are provided to mix the liquid, as next described. For example, the thermal inkjets of the mixing components 130 are understood to include respective microchannels 139, which receive the fluid therein from the inlet 110; as depicted, resistors of the thermal ejectors of the mixing components 130 may be located off-center in respective microchannels 139 (e.g. off-center with respect to sides of the microchannels 139) such that the liquid is ejected in directions into the example microchamber 120 (e.g. at the edge 134) that form a non-zero and/or a non perpendicular angle to the flow of the liquid into the chamber. In particular, in FIG. 2A, resistors of the thermal ejectors of the mixing components 130 are represented as squares inside respective microchannels 139 As previously mentioned, while the microchannels 139 are not depicted in FIG. 1 , they are generally understood to be present. Furthermore, as resistors of the thermal inkjets of the mixing components 130 are also off-center along a length of the microchannels 139 the thermal of the mixing components 130 generally act as pumps to push liquid through the microchambers 120. In particular, resistors of the thermal ejectors may be located within a first third of a length of a microchannel 139 (e.g. closest to the inlet 110) to provide pumping functionality.

[0055] For example, flow of the liquid into the example microchamber 120 from the thermal ejectors of the mixing components 130 in the respective microchannels 139 are indicated by arrows 140 which are at non-zero and/or non-perpendicular angles to the arrows 132. Hence, liquid is caused to flow from the edges 136 into the center 138 of the microchamber 120, and from the center 138 to the edges 136. As such, the thermal ejectors of the mixing components 130 are understood to mix the liquid in a laminar microflow formed by the microchamber 120 and, as depicted in FIG. 2A, the thermal ejectors of the mixing components 130 may be referred to as comprise thermal ejector mixers (e.g. located between the inlet and the microchamber 120).

[0056] Furthermore, comparing FIG. 1 and FIG. 2A, the thermal ejectors of the mixing components 130 in FIG. 1 are understood to represent a plurality of thermal ejectors of the mixing components 130 arranged relative to the edge 134. Hence, for example, one thermal ejector of a mixing component 130 in FIG. 1 is understood to represent a row of thermal ejectors of the mixing components 130 along a respective edge 134 of a microchamber 120 as depicted in FIG. 2A.

[0057] As such, the device 100 may comprise an array of thermal ejectors of the mixing components 130, for example a row of thermal ejectors of the mixing components 130 along a respective edge 134 of respective microchambers 120. For example, FIG. 2 B depicts a top view of the microchambers 120 with rows of thermal ejectors of the mixing components 130 respectively arranged along respective edges 134 of the microchambers 120. While as depicted there are eight microchambers 120 and eight thermal ejectors of the mixing components 130 to a microchamber 120 (e.g. for, as depicted, a total of sixty- four thermal ejectors of the mixing components 130) the device 100 may comprise any suitable number of microchambers 120 and/or thermal ejectors of the mixing components 130, and the like.

[0058] The dimensions of a microchamber 120 may be selected based on an expected size of a contaminant, but may also be selected based on a manufacturing technique thereof, and/or a target rate of flow of the liquid in a microchamber 120 and/or a heuristically determined distance that the UV light 137 may penetrate into the microchamber 120 from the edges 136.

[0059] For example, Escherichia coli bacteria (e.g. e-coli) may be a contaminant of water, and may be cylindrical with have dimensions of about 1 pm to about 2 pm long, with a radius of about 0.5 pm. As such, dimensions of a microchamber 120, and in particular a height thereof (e.g. a dimension perpendicular to the edges 134, 135, 136) may be selected to accommodate such dimensions and may be in a range of about 10pm to about 1000pm. However, in a particular example, a height of a microchamber 120 may be in in a range of about 300pm to about 500pm; for example, the microchambers 120 may be manufactured using 3D (three-dimensional) printing techniques which may have a lower limit for printing features in a range of about 300pm to about 500pm. [0060] However, other ranges of the height of the microchambers 120 are understood to be within the scope of the present specification and may be selected based on other types of contaminants (e.g. such as dimensions of viruses) and/or other types of manufacturing techniques (e.g. such as 3D lithography). Furthermore, dimensions of the microchambers 120 may be the same, or different, from one another (e.g. heights and/or dimensions of edges 134, 135, 136 of different microchambers 120 may be the same, or different, from one another).

[0061] Furthermore, a rate of flow of liquid in a microchamber 120 may depend on a height thereof, and/or dimensions of the edges 134, 135, 136. For example, the smaller the height, and/or dimensions of the edges 134, 135, 136, a smaller a rate of flow under gravity, and the larger the height, and/or dimensions of the edges 134, 135, 136, a larger a rate of flow under gravity. As such, a height of the microchambers 120 and/or height thereof, and/or dimensions of the edges 134, 135, 136 may be further selected to achieve a given flow rate through the device 100.

[0062] Similarly, dimensions of the edges 135, 136 may be selected heuristically based on penetration of the UV light 137 into the center 138, with the smaller the edges 135, 136 the greater the penetration of the UV light 137 into the center 138, with the larger the edges 135, 136 the smaller the penetration of the UV light 137 into the center 138 (e.g. due to a greater distance between the edges 136 and the center 138).

[0063] In a particular example, dimensions of the edges 134, 135, 136 may be in a range of about 1 cm to about 2 cm, selected heuristically to balance the above factors. Furthermore, the edges 134, 135, 136 may define channel widths and/or channel lengths of a microchamber 120. Hence, in some examples, the microchambers 120 may have channel heights dimensions in a range of about 300pm to about 1 mm, or in a range of about 300pm to about 500pm, and the microchambers 120 may have channel widths in range of about 1 cm to about 2 cm. [0064] Returning now to FIG. 1 , the microchambers 120 are understood to be disposed within the housing 105, to receive the ultraviolet light 137 from the light source 125. In one example, light source 125 may comprise UV-transparent windows (e.g. of UV-transparent glass and/or plastic) in the housing 105 for receiving sunlight into the microchambers 120; in some of these examples, such windows may further comprise UV-transparent windows that form the edges 136. Put another way, in these examples, the light source 125 in the form of UV- transparent windows generally enables sunlight, and/or light from any other external light source (e.g. UV lamps, and the like) to be received into the microchambers 120 to neutralize contaminants therein.

[0065] Regardless, the edges 136, as well as portions of the housing 105 that contain the edges 136, are understood to be UV transparent. In some of these examples, the edges 136 may be formed by outer walls of the housing 105. indeed, the walls 124 may also be UV transparent to promote transmission of UV light between the microchambers 120.

[0066] In other examples, light source 125 may comprise an ultraviolet light source, such as a lamp or UV light emitting diodes (LEDs) that emit UV light in a range of about 100 nm to about 280 nm (e.g. range of UV light that may be referred to as Ultraviolet C), which has germicidal properties (e.g. UV light in such wavelengths may kill and/or neutralize bacteria and/or viruses, for example via ionization thereof, among other possibilities). Such LEDs may be arranged (e.g. in an array) along the (e.g. UV transparent) edges 136 to emit UV light into the microchambers 120. Alternatively light diffusers may be used to diffuse light from the LEDs entering the edges 136 to provide more a UV light of about uniform intensity entering the edges 136. In particular use of UV light emitting diodes as the light source 125 may increase efficacy of the device 100 in producing potable water, and the like as compared to the use of sunlight only via UV transparent windows.

[0067] In a particular example UV emitting LEDs of the light source 125 may be mounted on opposite sides of each microchamber 120. However, in other examples, the LEDs of the light source 125 may be mounted in any suitable position at the device 100 and the device 100 may further comprise any suitable such optical components to convey the UV light 137 from the LEDs of the light source 125 to the microchambers 120 including, but not limited to sealed lenses at the LEDs in communication with optical fibers and/or optical chamber between the LEDs of the light source 125 and the microchambers 120. In other examples, reflective layers may be optionally integrated into LEDs of the light source 125 to amplify output of the UV light 137 by the LEDs (e.g. similar to lasing), to increase intensity of the UV light 137 and hence increase UV exposure of contaminants within the microchambers.

[0068] In some examples, as depicted, the device 100 may further include a photovoltaic power source 145, and the like, to power the thermal ejectors of the mixing components 130 and/or the LEDs of the light source 125, and/or any other electrical components of the device 100 as described herein. The photovoltaic power source 145 may comprise any suitable commercially available silicon cell, and the like; while as depicted, the photovoltaic power source 145 is external to the housing 105, with wiring 146 schematically depicted to the light source 125 and thermal ejectors of the mixing components 130, in other examples the photovoltaic power source 145 may be located at, and/or integrated with, outer walls of the housing 105 .

[0069] In some alternative examples, the device 100 may comprise a battery compartment to receive a battery (e.g. a rechargeable battery) to power the thermal ejectors of the mixing components 130 and/or the LEDs of the light source 125, and/or any other electrical components of the device 100 as described herein. In other examples, the device 100 may comprise the photovoltaic power source 145 and a battery compartment to receive a battery (e.g. so the device 100 may be powered in the daytime via the photovoltaic power source 145, and powered at nighttime via a battery).

[0070] In some examples, where the thermal ejectors of the mixing components 130 may function as pumps, such thermal ejectors may be operated to increase a rate of pumping as power from the photovoltaic power source 145 increases and/or the thermal ejectors may be operated to decrease a rate of pumping as power from the photovoltaic power source 145 decreases. Put another way, the device 100 may further include: the thermal ejectors of the mixing components 130 to move the liquid through the microchambers 120; and the photovoltaic power source 145 to power the light source 125 and the thermal ejectors of the mixing components 130 to pump and mix; furthermore, a rate of pumping of liquid by the thermal ejectors of the mixing components 130 may increase as power from the photovoltaic power source 145 increases, and/or as intensity of the ultraviolet light 137 produced by the light source 125 increases as the power from the photovoltaic power source 145 increases.

[0071] As the liquid exits the microchambers 120, the liquid is recombined, for example via various physical components 168 which direct liquid from the microchambers 120 towards the outlet 112, where the liquid may be collected at the bottle 116.

[0072] As depicted, in FIG. 1 , in some examples, a filter 170 may be located at the inlet 110 to filter and/or prevent particles of a given size from entering the inlet 110 and/or the microchambers 120. In some examples, the filter 170 may be selected to filter and/or prevent particles in a range of about 0.5 microns to about 50 microns from entering the device 100. In particular, the filter 170 may be selected to filter and/or prevent particles that are smaller than smallest dimension of the microchambers 120 (e.g. a smallest height) from entering the device 100. For example, the filter 170 may contain one sand, ash, clay, tissue, etc., and the like, to filter particles from fluid in the bottle 114 that might otherwise clog the inlet 110 to the device 100 and/or clog the microchambers 120. However, it is understood that biological contaminants, that are neutralized by the UV light 137, may not be filtered by the filter 170.

[0073] In some examples, the filter 170 may be replaceable.

[0074] Hereafter, control of certain components of the device 100 are described. Hence, while not depicted, it is understood that the device 100 may include any suitable number of circuits and/or processors, and/or any other suitable electronic components, and the like, to control certain components of the device 100 as described herein.

[0075] Attention is next directed to FIG. 3, which depicts the device 100 adapted to include a valve 300 located at the inlet 110. The valve 300 may be to prevent flow of the liquid into the microchambers 120 and/or the device 100 when the ultraviolet light 137 is below a threshold intensity, among other possibilities described hereafter. FIG. 3 is otherwise similar to FIG. 1 , and it is further understood that the arrangement components of the example of the device 100 depicted in FIG. 3 may be similar to as depicted in FIG. 2A and FIG. 2B.

[0076] For example, power produced by the photovoltaic power source 145 may depend on a brightness of sunlight to which the photovoltaic power source 145 is exposed. As such, the intensity of LEDs of the light source 125 may also depend on power produced by the photovoltaic power source 145 and/or brightness of sunlight to which the photovoltaic power source 145 is exposed (e.g. a bright sun on a sunny day may cause power output by the photovoltaic power source 145 to increase relative to a dim sun on a cloudy day). As understood herein, intensity of LEDs of the light source 125 may depend on such power, and, as such, when intensity of LEDs of the light source 125 decreases, intensity of the UV light 137 in the microchambers 120 may decrease. In these examples, the valve 300 may control a rate of flow of the liquid in the microchambers 120 to decrease, to allow contaminants in the liquid additional time to be exposed to the decreased intensity UV light 137.

[0077] For example, the valve 300 may comprise a throttling valve, and the like, powered by the photovoltaic power source 145, which, when power thereto increases, the valve 300 opens wider thereby increasing a rate of flow of liquid into the device 100, and, when power thereto decreases, the valve 300 narrows thereby decreasing a rate of flow of liquid into the device 100. As such, as power produced by the photovoltaic power source 145 increases, intensity of the UV light 137 may decrease and so does a rate of flow of liquid into the device 100; conversely, as power produced by the photovoltaic power source 145 decreases, intensity of the UV light 137 may increase as does a rate of flow of liquid into the device 100. In this manner, exposure of contaminants to the UV light 137 may be similar as the power produced by the photovoltaic power source 145 increases or decreases. Such functionality may be similar to that described above with respect to when the thermal ejectors of the mixing components 130 have pump functionality.

[0078] In yet further examples, control of the valve 300 may be threshold based, for example, based on intensity of the ultraviolet light 137. In these examples, the device 100 may further include a UV light sensor which detects intensity of the UV light 137, with the valve 300 opening wider as intensity of the UV light 137 increases, as detected by the UV light sensor, and the valve 300 narrowing as intensity of the UV light 137 decreases. Such a UV light sensor may be integrated into the light source 125 and the device 100 may include any suitable combination of electric and/or electronic components (e.g. transistors and the like) to open or close the valve 300 and/or a throttling device thereof, to control a rate of flow of liquid according to a signal of the UV light sensor. Alternatively, it is understood that intensity of the UV light 137 may be detected via detection of power produced by the photovoltaic power source 145. Alternatively, where the light source 125 comprises windows, as described above, a UV light sensor may be located at such windows.

[0079] In particular, regardless of how intensity of the UV light 137 may be detected and/or how the UV light 137 is produced, the valve 300 may be closed and/or narrowed to prevent, and/or partially prevent, flow of the liquid into the microchambers 120 and/or the device 100 when the ultraviolet light 137 is below a threshold intensity. For example, the threshold intensity may be preconfigured at electronic components of the device 100 and may represent an intensity of the ultraviolet light 137 below which neutralizing of contaminants in fluid may not be effective. In some of these examples, the device 100 may alternatively comprise a notification device, such as a display screen, and/or LED, and the like, which indicates when the ultraviolet light 137 is below a threshold intensity (e.g. an LED at the housing 105 may turn red and may otherwise be green, with such an LED also powered by the photovoltaic power source 145).

[0080] In yet further examples that include a battery compartment, with a battery therein, at the device 100, when intensity of the UV light 137 is below such a threshold intensity (and/or another suitable threshold intensity), LEDs of the light source 125 and the valve 300 (and other electronic components of the device 100) may be powered by the battery.

[0081] Put another way, the valve 300 may be to selectively open and close (and/or selectively partially open and partially close) to control a rate of flow of liquid to the microchambers 120. Put yet another way, the valve 300 may be light sensitive to prevent flow of liquid into the device 100 when the UV light 137 is not sufficient for contaminant treatment.

[0082] Attention is next directed to FIG. 4 which depicts the device 100 adapted to include thermal ejector pumps 400 to move the liquid through the microchambers 120. For example, as depicted, the thermal ejector pumps 400 may comprise thermal ejector pull-pumps located between the microchambers 120 and the outlet 112. In particular, the thermal ejector pumps 400 (e.g. thermal ejector ejectors thereof) are located within microchannels and/or within a first third of a length of a microchannel (e.g. closest to the microchambers 120) to provide pumping functionality. FIG. 4 is otherwise similar to FIG. 1 , and it is further understood that the arrangement of components of the example of the device 100 depicted in FIG. 3 may be similar to as depicted in FIG. 2A and FIG. 2B. Hence, in these examples, the mixing components 130 may comprise thermal ejector mixers located between the inlet 110 and the microchambers 120 (e.g. similar to as depicted in FIG. 2A).

[0083] In particular, the thermal ejector pumps 400 may assist with moving the liquid through the microchambers 120, for example to obtain a given flow rate in the event that gravity alone does not result in such a given flow rate. For example, as has been described herein, exposure of contaminants in liquid moving through the microchambers 120 may depend on a flow rate thereof. However, the flow rate of liquid moving through the microchambers 120 generally also affects a rate at which the liquid exits through the outlet 112. As such, the thermal ejector pumps 400 may be activated to achieve a given flow rate at the outlet 112 and/or the thermal ejector pumps 400 may be in an always “on” state as long as the device 100 is powered. Put another way, the thermal ejector pumps 400 are understood to be powered by the photovoltaic power source 145 and/or a battery (when present), and may be always on to assist with pumping of liquid through the device 100. In some of these examples the device 100 may be further adapted to include the valve 300 to assist with controlling the flow rate as described above. However, in other examples, the device 100 may include a flow sensor at the outlet 112, and the like, and the thermal ejector pumps 400 (and/or the valve 300) may be controlled in a feedback loop with a signal from the flow sensor to achieve a given flow rate as measured by the flow sensor.

[0084] In a particular examples, the thermal ejector pumps 400 may be to achieve a flow rate at the outlet 112 of 1 liter per 8 hours, however other flow rates are within the scope of the present specification.

[0085] Furthermore, in some examples, the thermal ejectors (e.g. thermal ejector mixers) of the mixing components 130 may be replaced by (and/or may be adapted to include) thermal ejector push-pumps that both mix the liquid of the laminar microflows in the microchambers 120 and push the liquid through the microchambers 120 (e.g. by pulling liquid into a thermal ejectors and pushing the liquid out); in these examples, the thermal ejector pumps 400 may be present or omitted. Put another way, the thermal ejectors (e.g. thermal ejector mixers) of the mixing components 130 may include thermal ejector push- pumps that both mix liquid, and which achieve a given flow rate at the outlet 112, as described above.

[0086] However, the thermal ejector pumps 400 may be operated to increase a rate of pumping as power from the photovoltaic power source 145 increases and/or the thermal ejector pumps 400 may be operated to decrease a rate of pumping as power from the photovoltaic power source 145 decreases. In other words, the functionality described with respect to the valve 300 and/or the thermal ejectors of the mixing components 130 may be similarly implemented via the thermal ejector pumps 400. Put another way, the device 100 may further include: the thermal ejector pumps 400 to move the liquid through the microchambers 120; and the photovoltaic power source 145 to power the light source 125 and the thermal ejector pumps; furthermore, a rate of pumping of liquid by the thermal ejector pumps 400 may increase as power from the photovoltaic power source 145 increases, and/or as intensity of the ultraviolet light 137 produced by the light source 125 increases as the power from the photovoltaic power source 145 increases.

[0087] Attention is next directed to FIG. 5 which depicts a perspective view of a block diagram of a portion of a housing 105 (e.g. depicted without the inlet 110 and the outlet 112) according to some examples that includes eight microchambers 120. The housing 105 of FIG. 5 is further depicted with the light source 125 located at the edges 136 to emit the UV light 137 into the microchambers 120, and the photovoltaic power source 145 located along a surface of the housing 105 that is perpendicular to the light source 125. The housing 105 of FIG. 5 is further annotated to show a direction of “FLOW” of liquid as well as a length “L” of the microchambers 120 (e.g. corresponding to a length of the edges 136), a width “W’ of the microchambers 120 (e.g. corresponding to a width of the edges 134, 135), and a total height “H” of the eight microchambers 120. A height of an individual microchamber 120 is understood to be in a direction of the total height “H”, but is between adjacent walls 500 of the microchambers 120.

[0088] Hence, in FIG. 5, it is understood that the housing 10 has been adapted to include eight microchambers 120 separated by the walls 500 which may be similar to the walls 124 other than as described hereafter. In particular, the walls 500 may comprise alternately polarized microchambers walls; for example, the walls 500 are depicted with a “+” or a respectively indicating whether a wall 500 is positively or negatively electrically polarized, for example as powered by the photovoltaic power source 145 and/or any other suitable electrically polarizing circuits. Such polarization generally results in an electric field between opposing walls 500 of a microchamber 120.

[0089] However, any suitable polarization scheme for the walls 500 is within the scope of the present specification. For example, while as depicted a wall 500 is either positively or negatively electrically polarized, in other examples, first portions of a first wall 500 may be electrically polarized to a first electrical polarization state (e.g. positive or negative electrical polarization), and second portions of the wall 500 may be electrically polarized to a second electrical polarization state (e.g. the other of positive or negative electrical polarization) opposite to that of the electrical polarization state. Similarly, respective portions of an adjacent wall 500, opposite polarized portions of the first wall 500, may be in an opposite electrical polarization state to the polarized portions of the first wall 500. Hence, for example, a portion of a first wall 500 that is positively electrical polarized may face a respective portion of an adjacent wall 500 that is negatively electrical polarized and, similarly, a portion of a first wall 500 that is negatively electrical polarized may face a respective portion of an adjacent wall 500 that is positively electrical polarized.

[0090] In particular, an electric field may be generated though a microchamber 120 by applying a voltage differential across alternating anode/cathode pairs of the walls 500 (e.g. negative and positively charged walls 500) to polarize and/or electrolyze and/or ionize the liquid (e.g. water) of the laminar flows in the microchambers 120. Such a process may produce oxidizing agents such as negative ions and active atomic oxygen, which may react with the biological contaminants in the fluid and/or water to kill and/or neutralize such biological contaminants, and/or the polarized walls 500 may attract ionized contaminants (e.g. which may be produced by the UV light 137 to kill and/or neutralize the contaminants) thereby moving such ionized contaminants “out of the way” of non-ionized contaminants to increase a likelihood of the UV light 137 also killing and/or neutralizing such contaminants . As such, polarization of the walls 500 may provide a second mechanism to kill and/or neutralize such biological contaminants in addition the UV light 137, and/or polarization of the walls 500 may increase the efficacy of the UV light 137; regardless, polarization of the walls 500 may increase efficacy of the device 100 in producing potable water, and the like.

[0091] As mentioned above, the microchambers 120 may be 3D printed using any suitable 3D printing material and any suitable 3D printing machine. In these examples, the material of the walls 500 are understood to include a material that may be 3D printed, and electrically polarizable, and/or the material of the walls 500 are understood to include a material that may be 3D printed and coated with a material that is electrically polarizable. For example, some 3D printing machines function by 3D printing additive layers of fused materials using a powder material as a starting material; such a process may be halted to insert a layer of conductive material (e.g. may also be nano-porous, see below), then resumed and so on and so forth layer by layer (e.g. to 3D print the walls 500 and/or other walls of the housing 105); when such a process is completed, unfused powder material may be ejected leaving the microchambers 120 in between the layers.

[0092] In some examples, the walls 500 may be nanoporous to assist with production of oxidizing agents as described above. For example, such nanoporousity may include small pits and/or divots, and the like (e.g. on a nanoscale and/or on any other suitable scale), in the walls 500 to increase a surface area of the walls 500 (e.g. as compared to walls that are not nanoporous and/or walls that are smooth); such an increase in surface area generally increases rate of production oxidizing agents that assist with killing and/or neutralizing the biological contaminants in the liquid.

[0093] In particular examples, the materials of the walls 500 (and/or the microchambers 120) may include, but is not limited to, silicon, acrylic, a cyclic olefin copolymer, Ti02, and the like, in combinations that enable the walls to be 3D printed, and electrically polarizable. In some examples, the materials of the walls may be further selected to be transparent to the UV light 137, as described above (e.g. materials of the walls 500 may include a clear (e.g. UV transparent) acrylic and/or a cyclic olefin copolymer coated with a layer of Ti02 that has a thickness selected to be at least partially transparent to the UV light 137).

[0094] In a particular example, a width “W” of the housing 105 may be about 1 cm with a length “L” of about 2 cm, and a height Ή” of less than, or equal to, about 1 cm, with the height of a microchamber 120 (e.g. a perpendicular distance opposing walls 500) being about 0.1 mm. Ranges of the width “W” and the length “L” are described previously with respect to ranges of the edges 134, 135, 136, as is a range the height of a microchamber 120. The height Ή” of the housing 105 may be in range of about 0.5 cm to about 2 cm.

[0095] As mentioned above, dimensions of housing 105 and/or the microchambers 120 may be selected to obtain a given flow rate from the outlet 112. Furthermore, combinations of numbers of microchambers 120, the polarized walls 500, and nanoporousity thereof, as well as the light source 125 comprising UV transparent windows and/or UV emitting LEDs, to achieve a given level of decontamination of liquid and/or water passing through the microchambers 120. In a particular examples, may be selected to achieve depend on desired throughput and whether sunlight alone is used to decontaminate the water, or a combination of solar, polarization and nano- porous/conductive walls 500 are used with or without UVC emitting LEDs of the light source 125. In some examples, sunlight (and/or sunlight alone) may have particular benefits due to the high intensity of Ultraviolet C light in sunlight.

[0096] In some examples, the portion of the housing 105 depicted in FIG. 5 may be a unit which may be joined with other units to form longer microchambers 120 and/or stages of the microchambers 120.

[0097] For example, attention is next directed to FIG. 6 which depicts a plurality of units of the housing 105 as depicted in FIG 5, which are joined by structural components 600 provided between successive stages of microchambers 120 (e.g. a stage of a microchamber 120 corresponding to a portion of a microchamber 120 of one unit of the housing 105). In some examples, a structural component 600 may comprise a frame, and the like, for joining units of the housing 105 and aligning stages of the microchambers 120, for example to increase a length of the microchambers 120 and hence increase exposure of contaminants in the liquid flowing in laminar microflows there to. For example, as depicted in FIG. 6, the light source 125 may extend along the length of the units of the housing 105.

[0098] However, in other examples, the structural components 600 may be adapted to mix and/or twist and/or shift liquid within the microchambers 120 (e.g. see FIG. 7A, FIG. 7B and FIG. 7C), and/or contaminants thereof, and/or the structural components 600 may be adapted to include a microfluidic network of microfluidic pipes (e.g. see FIG. 8), combined with thermal ejectors, to mix liquid within the microchambers 120. Hence, the structural components 600 may be adapted to include various type of mixing components which may be provided in place of, and/or in addition to, the thermal ejectors of the mixing components 130. Various examples of the structural components 600 are next described with respect to FIG. 7A, FIG. 7B , FIG. 7C, FIG. 8, FIG. 9A, FIG. 9B, FIG. 9C and FIG. 9D.

[0099] Attention is next directed to FIG. 7A, FIG. 7B , FIG. 7C, which shows structural components 700 (e.g. the structural components 600 may comprise the structural components 700) provided in the form of micro-twisting layers 710, 720, 730 and 740 between stages 745-1 , 745-2, 745-3 of a microchamber 120 and/or within microchamber 120, the micro-twisting layers 710, 720, 730 and 740 to passively twist or shift the liquid within the microchambers 120 and/or the micro-twisting layers 710, 720, 730 and 740 to passively twist or shift contaminants in the liquid within the microchambers 120 as described hereafter. The stages 745-1 , 745-2, 745-3 are interchangeably referred to hereafter, collectively, as a stage 745 and, generically, as a stage 745. Furthermore, while three stages 745 are depicted, a microchamber 120 may include any suitable number of at least two stages 745 as indicated by the dashed lines extending from the stage 745-3. [00100] FIG. 7 A is a schematic top view of a portion of the device 100 shown in FIG. 6, with the structural components 700 between sections and/or units of the microchambers 120 (e.g. sections and/or units of the housings 105). FIG. 7B is a detailed perspective view of a structural component 700 comprising micro twisting layers 710, 720, 730 and 740 to twist the laminar microflows in the microchambers 120 by 45 degrees per structural component 700. For example, the micro-twisting layers 710, 720, 730 and 740 comprise an array of respective apertures which are aligned with each other (e.g. in a one-to-one relationship), with apertures of the twisting layer 710 being about square, apertures of the twisting layer 720 comprising slits, apertures of the twisting layer 730 comprising slits that are about 45° to the slits of the twisting layer 720, and apertures of the twisting layer 740 being about square and about 45° to the apertures of the twisting layer 710. As such, liquid passing through the adjacent apertures, as well as contaminants contained in the liquid, may rotate by about 45°. Hence, as liquid, and/or contaminants thereof, pass through a structural component 700, from one stage 745 of a microchamber 120 to a next stage 745, liquid and/or contaminants may rotate by about 45° with respect to edges 136 of the microchamber 120 and/or with respect to the light source 125. As such, contaminants located between the light source 125 and other contaminants, may be rotated between stages 745 of the microchambers 120, relative to the other contaminants, such that the other contaminants are no longer shadowed.

[00101] For example, FIG. 7C is a schematic front view representation of three contaminant particles 750, 760 and 770 in fluid flowing through the device 100 being exposed to UV light 137 produced by LEDs of the light source 125. In particular, the contaminant particles 750, 760 and 770 are understood to be viewed along a direction of the flow of the liquid through the stages 745 of the microchambers 120

[00102] At the first stage 745-1 of the microchambers 120, the two particles 750, 760 are shadowed by a left-most particle 770 such that the particle 770 is exposed to the UV light 137 produced by LEDs of the light source 125 while the particles 750 and 760 are blocked from the UV light 137. As a result of the structural component 700 between the stages 745-1 , 745-2, the liquid of the laminar microflows in the microchambers 120 are twisted by 45 degrees so that the particles 750, 770 are exposed to the UV light 137 at the second stage 745- 2, while the particle 760 is blocked from the UV light 137 by the particle 750. However, as a result of the result of the structural component 700 between the stages 745-2, 745-3, the liquid of the laminar microflows in the microchambers 120 are twisted by a further 45 degrees for a total of 90 degrees so that all the particles 750, 760 and 770 are exposed to the UV light 137.

[00103] The micro-twisting layers 710, 720, 730, 740 may further mix liquid in the laminar flows of the microchambers. Hence, in these examples, the device 100 may be adapted to include mixing components in the form of the micro twisting layers 710, 720, 730, 740 within the microchambers 120 (which are understood to be provided in sections and/or stages 745), the micro-twisting layers 710, 720, 730, 740 to passively twist or shift the liquid within the microchambers 120. The terms “passive” and/or “passively” are used in this context as the micro-twisting layers 710, 720, 730, 740 perform the twisting and/or shifting and/or mixing without active electronic components such as thermal ejectors.

[00104] Attention is next directed to FIG. 8 which depicts another example mixing component provided in the form of a microfluidic network 800 which may be used in place of thermal ejectors of the mixing components 130, or in addition to the thermal ejectors of the mixing components 130. Furthermore, such a microfluidic network 800 may be used in place of a structural component 700 (e.g. between stages 745 of microchambers 120) and/or with a structural component 700 (e.g. the structural components 600 may comprise the microfluidic network 800). Put another way, the device 100 may be adapted to include mixing components which comprise a microfluidic network 800 of microfluidic pipes located within the microchambers 120 or connecting the microchambers 120 (e.g. connecting stages 745 of the microchambers 120). [00105] As depicted, the microfluidic network 800 comprises a microfluidic network of microfluidic pipes and may comprise any suitable material including, but not limited to, a material transparent to the UV light 137, including, but not limited to, material that is printable using 3D printing techniques. In other examples, portions of the microfluidic network 800 may be UV reflective to reflect the UV light 137 into the microfluidic pipes (e.g. a path of one example micropipe is represented by the arrow 810, described below).

[00106] In particular, microfluidic pipes of the microfluidic network 800 may receive particles 760, 770, 770 in liquid in a laminar microflow, “turn” the particles 760, 770, 770 in the liquid by 90°, guide the particles 760, 770, 770 in the liquid a distance perpendicular to flow of the laminar microflow, and then “turn” the particles 760, 770, 770 in the liquid again by 90° so that the particles 760, 770, 770 in the liquid again flow in a direction of the flow of the laminar microflow. One example path of the particles 760, 770, 770 through a micropipe is indicated by an arrow 810. The result is that the particles 760, 770, 770 in the liquid are shifted towards an edge 136 and/or towards the light source 125 as the liquid flows through the microfluidic pipes of the microfluidic network 800, and which mixes the liquid in the laminar microflows of the microchambers 120 (e.g. between the stages 745). Flow through a micropipe may also result in twisting and/or shifting of the particles 760, 770, 770 relative to each other.

[00107] Furthermore, the micropipes may be provided in rows, with micropipes in a given row shifting liquid in the laminar microflows of the microchambers 120 in one direction, as indicated by the arrows 811 , and micropipes in an adjacent row shifting liquid in the laminar microflows of the microchambers 120 in an opposite direction, as indicated by the arrows 812. Endmost micropipes in a given row may shift liquid in the laminar microflows of the microchambers 120 in a direction perpendicular to a direction of a given row, as indicated by the arrows 813, 814; for example, as indicated by the arrows 811 , 812, 813, 814, shifting of liquid may occur in a loop (e.g. along successive stages 745 of the microchambers 120, assuming such stages 745 are separated by respective microfluidic networks 800. However, it is understood that, when liquid exits a microfluidic pipe, overall flow of the liquid is still in a direction indicated by the arrow “FLOW”.

[00108] As such, a microfluidic network 800 between adjacent stages 745 generally shift fluid of the laminar microflows are shifted back and forth between opposite edges 136 and/or opposite sections of the light source 125, to better expose contaminants therein to the UV light 137.

[00109] Furthermore, the micropipes may further subject the contaminants to various other forces, at least by virtue of the contaminants flowing through a constricted space, which may result in compression in various directions, asymmetrical shifting, acceleration, and/or expansion in various directions, and the like, to better expose contaminants therein to the UV light 137.

[00110] In some examples, as shown in FIG. 9A, a microfluidic network 800 may be adapted to include thermal ejectors to pump the liquid through the microfluidic pipes. Put another way, the device 100 may be adapted to include mixing components which comprise a microfluidic network 800 of microfluidic pipes located within the microchambers 120 or connecting the microchambers 120 (e.g. connecting stages 745 of the microchambers 120), the microfluidic network 800 further comprising thermal ejectors to pump the liquid through the microfluidic pipes.

[00111] For example, in FIG. 9A, which depicts a portion 900 of a row of the micropipes of the microfluidic network 800, additional mixing and/or pumping elements, provided in the form of thermal ejectors 902, 904, may be provided, and formed using conductive layers 905 “above” and “below” a row of the microfluidic network 800; while the terms “above” and “below” (e.g. and “top” and “bottom”) are used to describe the positions of the conductive layers 905 relative to the portion 900, such terms are used with respect to the orientation of FIG. 9A only and it is understood that conductive layers 905 and the microfluidic network 800 may be in any suitable orientation. The conductive layers 905 may be formed using photolithographic techniques and/or any other suitable technique. [00112] In particular, in FIG. 9A, a plurality of conductive layers 905 may be respectively positioned between individual rows of the microfluidic network 800; as depicted, two conductive layers 905 are shown above and below the portion 900 of the row of the microfluidic network 800. The conductive layers 905 are depicted in dashed lines to show their relative positions to the portion 900, but are understood to be provided in a sheet-like and/or planar format.

[00113] As depicted, in FIG. 9A, a conductive layer 905 may include a bend 906, and the like, at an edge that is furthest from the microfluidic network 800 (e.g. and/or the depicted portion 900) to further randomize flow of liquid and/or break the parabolic flow; while as depicted the respective bend 906 for both the depicted conductive layers 905 is in a same direction, the bends 906 may be different for different conductive layers 905 and/or a bend 906 may not be uniform (e.g. an edge of a conductive layer 905 that is furthest from the microfluidic network 800 may be bent and/or curved, and the like, in different directions). A conductive layer 905 may otherwise include regions 930 that may be about perpendicular to microfluidic network 800 (e.g. such as the portion 900 depicted in FIG. 9A).

[00114] In particular, a conductive layer 905 may be fabricated from a printed circuit board (PCB) having conductive bands 910, for example, at least in a region of a bend 906. Hence, for example, a conductive layer 905 may be conductive in a region of a conductive band 910, and otherwise may be insulating. The conductive bands 910 may be alternately polarized (e.g. at alternate conductive layers 905) to generate electric fields therebetween to assist with production of oxidizing agents to kill and/or neutralize such biological contaminants, similar to as described above with respect to the walls 500. Also similar to the walls 500, the conductive bands 910 may be nanoporous. Also similar to the walls, the conductive layers 905 also be UV-transparent and/or partially UV transparent.

[00115] While not depicted, a conductive layer 905 may further comprise copper traces (not depicted), and the like, for powering the thermal ejectors 902, 904, for example to electrically connect the photovoltaic power source 145 to the thermal ejectors 902, 904. As depicted a thermal ejector 902 may be “upward” facing and positioned on a “top” surface of a conductive layer 905 (e.g. as indicated by the thermal ejector 902 being depicted in solid lines), and a thermal ejector 904 may be “downward” facing and positioned on a “bottom” surface of a conductive layer 905 (e.g. as indicated by the thermal ejector 904 being depicted in broken lines). In addition to dispersing particles (e.g. such as the particles 750, 760, 770), when positioned 1/3 into respective micropipes (e.g. and/or between the rows of the micropipes of the microfluidic network 800), the thermal ejectors 902, 904 may also function as pumps within the micropipes, for example to pump the liquid along the path indicated by the arrow 810 in FIG. 8, and/or to pump liquid in the microchambers 120. Furthermore, while a direction of pumping of the thermal ejectors 902, 904 is indicated by arrows extending from the thermal ejectors 902, 904, a direction of pumping may be in any suitable direction, for example to pump the liquid along through a micropipe.

[00116] Furthermore, while only two thermal ejectors 902, 904 are depicted in FIG. 9A, it is understood that a conductive layer 905 may comprise a row of thermal ejectors 902, 904 along a respective row of the micropipes of the microfluidic network 800. A conductive layer 905 may further comprise more than one row of thermal ejectors 902, 904 and/or more than one conductive band 910.

[00117] For example, attention is next directed to FIG. 9B which depicts another example conductive layer 905 in which thermal ejectors 902, 904 are arranged in rows and alternate with conductive bands 910. At least one of the rows of thermal ejectors 902, 904 may be at a row of the micropipes of the microfluidic network 800, as depicted in FIG. 9A, however other rows of the thermal ejectors 902, 904 may be positioned away from the microfluid network 800, for example towards an edge of a conductive layer 905 that is furthest from the microfluid network 800 (and which may, or may not be, bent). [00118] As also depicted in FIG. 9B, a conductive layer 905 may further comprise holes 940 therethrough to provide channels for liquid flow between the conductive layers 905. While as depicted the holes 940 are at ends of rows of the thermal ejectors 902, 904, the holes 940 may be located at any suitable position. In some examples, an area of the holes 940 may be in a range of about 0.01 mm ² to about 1 mm ² ; in a particular example, an area of the holes 940 may be about 0.09 mm ² (e.g. square holes of about 0.3 mm by 0.3 mm), however the holes 940 may be of any suitable size.

[00119] FIGS. 9C and 9D show end conductive layers 905 which may be respectively located above a top row of the microfluidic network 800 and beneath a bottom row of the microfluidic network 800. For example, the conductive layer 905 of FIG 9C includes thermal ejectors 904 which face “down”, and the conductive layer 905 of FIG 9D includes thermal ejectors 902 which face “up”. While conducting bands 910 of the conductive layer 905 of FIG 9D are depicted, and conducting bands 910 of the conductive layer 905 of FIG 9C are not depicted, conducting bands 910 may nonetheless be present at the conductive layer 905 of FIG 9C.

[00120] While the conductive layers 905 are one example of providing thermal ejectors with the microfluidic network 800, thermal ejectors may alternatively be located at, and/or on, and/or in, the microfluidic network 800 using any suitable manufacturing techniques (e.g. photolithography and/or 3D printing).

Regardless, it is understood that, in some examples, mixing components provided herein may comprise a microfluidic network of microfluidic pipes, the microfluidic pipes located within the microchambers or the microfluidic pipes connecting the microchambers, the microfluidic network further comprising thermal ejectors to pump the liquid through the microfluidic pipes (e.g. the thermal ejectors provided at the microfluidic network 800 and/or via the conductive layers 905 and/or in any other suitable manner).

[00121] Furthermore, in some examples, mixing components provided herein may comprise a microfluidic network of microfluidic pipes, the microfluidic pipes located within the microchambers or the microfluidic pipes connecting the microchambers, and the microfluidic network and/or walls of the microfluidic network and/or the conductive layers may be nano-porous, conductive, UV reflective and/or UV transparent. For example, portions of the walls of the microfluidic network 800 (e.g. which form the micropipes) may be UV transparent while other portions may be UV reflective, for example to reflect the UV light 137 into the micropipes to better expose contaminants flowing therethrough to the UV light 137.

[00122] Furthermore, in view of the discussion of the various mixing components, and polarizable components (e.g. the walls 500 and/or the conductive bands 910), it is understood that the photovoltaic power source 145 is generally to power the light source 125 and/or to power various mixing components, such as thermal ejectors) and/or to power polarizable components (such as microchambers walls 500).

[00123] Attention is next directed to FIG. 10 which depicts an example method 1000 of operating the device 100. The method 1000 may be implemented by physical features of the device 100 and/or by electronic components of the device 100, as described herein. The method 1000 need not be performed in the exact sequence as shown and likewise various blocks may be performed in parallel rather than in sequence. Accordingly, the components of the method 1000 are referred to herein as “blocks” rather than “steps.” The method 1000 may be implemented on variations of the device 100 of FIG. 1.

[00124] At a block 1002, the device 100 receives liquid at the inlet 110. For example, the device 100 may be attached to the bottles 114, 116 as described above, and the device 100 and the bottles 114, 116 may be positioned such that gravity pulls liquid from the bottle 114 into the inlet 110. In some examples, the valve 300 may be operated to open to receive liquid at the inlet 110 from the bottle 114. As has been extensively described, the liquid may be contaminated with contaminants and/or biological contaminants which may be killed and/or neutralized via UV light 137. [00125] At a block 1004, the liquid is divided into the microchambers 120 of the device 100 forming laminar flows of the liquid. In some examples, the dividing at the block 1004 may occur via the physical dividers 122, while in other examples the dividing may be assisted by operating the thermal ejectors of the mixing components 130 and/or the thermal ejector pumps 400 to pump the liquid into the microchambers 120.

[00126] At a block 1006, the laminar microflows of the liquid in the microchambers are exposed to the ultraviolet light 137 provided by the light source 125 of the device 100. For example, when the light source 125 comprises UV transparent windows at the edges 136, the block 1006 may be implemented merely by virtue of the UV light 137 of sunshine entering the microchambers 120. However, in other examples, when the light source 125 comprises UV emitting LEDs, the block 1006 may be implemented by providing power to the LEDs to turn on, for example automatically when power is generated by the photovoltaic source 145. Regardless, exposure of the contaminants in the liquid to the UV light 137 may kill and/or neutralize such contaminants to “purify” the liquid, and the like, and/or render the liquid potable.

[00127] As has also been described, at the block 1006, walls 500 of the microchambers 120 and/or the conductive bands 910 may be polarized to assist with killing and/or neutralizing contaminants in the liquid.

[00128] At a block 1008, the liquid in the laminar microflows of the microchambers 120 is mixed using mixing components of the device 100 to randomize flow of liquid in the microchambers or break parabolic flow of liquid in the microchambers 120. As has already been extensively described, the mixing components may comprise thermal ejectors (e.g. as depicted in FIG. 1 and FIG. 2A) and/or the micro-twisting layers 710, 720, 730 and 740 and/or the microfluidic network 800 and/or thermal ejectors 902, 904 of the conducting layers 905, and the like. Hence, the block 1008 may be implemented by providing power to thermal ejectors, for example automatically when power is generated by the photovoltaic source 145 and/or the block 1008 may be implemented by presence of the micro-twisting layers 710, 720, 730 and 740 and/or the microfluidic network 800 between stages 745 of microchambers 120.

[00129] At a block 1010 the laminar microflows of the liquid from the microchambers 120 are recombined at the outlet 112 of the device 100 and, for example, the liquid may exit the device 100 via the outlet 112 into the bottle 116 where the liquid is collected. In some examples, as has already been described, the recombining at the block 1010 may occur via the physical components 168, while in other examples the recombining may be assisted by operating the thermal ejectors of the mixing components 130 and/or the thermal ejector pumps 400 to pump the liquid out of the microchambers 120.

[00130] The example device 100 may provide a simple, affordable low-cost solution to providing potable water in areas where clean water is unavailable. Over eight hours of a cloudy day, it is contemplated that the device 100 may process one liter of clean water. During brighter days, higher clean water throughput may be possible. With the addition of thermal ejector pumps and/or a dedicated source of light, such as LEDs, even higher throughput rates may be possible.

[00131] It should be recognized that features and aspects of the various examples provided above may be combined into further examples that also fall within the scope of the present disclosure.