BACKGROUND

[0001] Various sensing devices are currently available for sensing different attributes of fluid, such as blood. In some cases, a microfluidic apparatus incorporating microfluidic devices are used to analyze an anaiyte. This microfluidic device may allow a fluid to pass by a sensing device in order to accomplish that analysis.

BRIEF DESCRI PTION OF THE DRAWINGS

[0002] The accompanying drawings illustrate various examples of the principles described herein and are part of the specification. The illustrated examples are given merely for illustration, and do not limit the scope of the claims.

[0003] Fig. 1 is a block diagram of a microfluidic apparatus according to an example of the principles described herein.

[0004] Fig. 2 is a block diagram of a microfluidic system according to an example of the principles described herein.

[0005] Fig. 3 is a block diagram of a microf!uid fluid analyzer according to an example of the principles described herein.

[0006] Fig. 4 is a block side cutout view of a microfluidic system according to an example of the principles described herein,

[0007] Fig. 5 is a block side cutout view of a microfluidic system (500) according to an example of the principles described herein. [0008] Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings.

DETAILED DESCRIPTION

[0009] icrofluidic apparatus that incorporate microfluidic devices are often fabricated on the sub-millimeter scale. These microfluidic devices often deal with the behavior, precise control, and/or manipulation of fluids that are geometrically constrained at this sub-millimeter scale. As a consequence of such small scales, microfluidic devices may consume energy at a relatively lower rate than non-micro scale analyzing devices as well as, in some cases, be disposable.

[0010] In some examples, the microfluidic apparatus may include channels to direct a fluid towards the microfluidic devices in the channel. In these examples, the fluid flow should be maintained such that smooth fluidic flow from one microfluidic device to another may be realized. Without this smooth fluidic flow, an analyte may not be analyzed appropriately.

[0011] Additionally, the microfluidic devices may be distinct from one another with each or, at least two of the microfluidic devices being made of different materials, fabrication processes, and/or shapes. Forming these distinct microfluidic devices into a single co-planar package allows for multi-physic integration of the microfluidic devices reducing the cost of manufacture.

[0012] The present specification, therefore, describes a microfluidic apparatus that includes at least two microfluidic devices embedded into a substrate, at least a first microfluidic device of the microfluidic devices being heterogenous to at least a second microfluidic device and a microfluidic channel to fiuidicaliy coupling the microfluidic devices to each other. [0013] The present specification also describes a microf!uidic system that includes a substrate and at least two microfluidic devices embedded into the substrate, at least one of the microfluidic devices being different from a remaining number of microfluidic devices.

[0014] The present specification further describes a microfluidic fluid analyzer that includes at least two microfluidic devices embedded into the substrate, microfluidic devices being copianar to each other, a cap formed over the embedded microfluidic devices, the cap forming a microfluidic channel between the embedded microfluidic devices and the cap.

[0015] Fig. 1 is a block diagram of a microfluidic apparatus (100) according to an example of the principles described herein. The microfluidic apparatus (100) may include a substrate (1 10) with a number of microfluidic devices (105) embedded therein and a microfluidic channel (1 15) to fluidically couple the microfluidic devices (105) to each other.

[0016] The substrate (1 10) may be any type of substrate (1 10) into which the microfluidic devices (105) may be embedded, in an example, the substrate (1 10) is epoxy mold compound (EMC), in an example, the substrate (1 10) is formed into a single layer to embed the microfluidic devices (105) therein.

[0017] The microfluidic devices (105) may be any type of active or passive microfluidic devices (105). Examples of active microfluidic devices (105) include integrated circuits (ICs), thermal Inkjet dies, Piezo printhead dies, sensors, actuators, microeiectromechanical systems (MEMS), heaters, light- emitting diodes (LEDs), lasers, electrodes, among others. Examples of passive microfluidic devices (105) includes waveguides, lead frames, cooling plates, tubes, antennas, mechanical filters, printed circuit boards (PCBs), molded components, radio-frequency identification (RF ID) tags, lead zirconate titanate (PZT) devices, among others. Consequently, the present specification describes a microfluidic apparatus (100) that provides for multi-physic integration of heterogeneous or diverse microfluidic devices (105) into the microfluidic apparatus (100).

[0018] In addition to each of the microfluidic devices (105) being diverse as to their functionality, they may also be diverse as to the materials used to make each of the microfiuidic devices (105), The present specification, therefore, contemplates that each of the microfiuidic devices (105) are made from different materials respective of each other. Thus, embedding each of the microfiuidic devices (105) into the substrate (1 10) allows for this diversity of materials among the microfiuidic devices (105) to be used. The materials used to make each of the microfiuidic devices (105) may include plastics, ceramics, metals, and silicon, among other types of materials. This results in a relatively more inexpensive microfiuidic apparatus (100) than would similar devices that were made within a silicon wafer, for example.

[0019] The microfiuidic devices (105) may each be embedded into the substrate (1 10) such that the microfiuidic devices (105) are each co-planar to each other. In an example, this allows for a relatively smoother fluid flow over the microfiuidic devices (105) as well as from microfiuidic device (105) to microfiuidic device (105). During use of the microfiuidic apparatus (100), this may allow for better analysis of an anaiyte passed by the microfiuidic devices (105). The placement of the microfiuidic devices (105) within the substrate (1 10) also allows for the integration of the microfiuidic devices (105) made with different materials, fabrication processes, of shapes. Consequently, the co- planar nature of the embedded microfiuidic devices (105) allows for a number of different types of analytical devices being made within the microfiuidic apparatus (100).

[0020] The microfiuidic apparatus (100) may further includes a

microfiuidic channel (1 15). in an example, the microfiuidic channel (1 15) is formed between the co-planar microfiuidic devices (105) and a lid. The lid may be made of any type of material that allows for a smooth microfiuidic channel (1 15) to be formed in order to provide for analysis of an anaiyte that passes over the co-planar microfiuidic devices (105). In an example, the lid includes an input port that allows an anaiyte to pass into the microfiuidic channel (1 15) and past the co-planar microfiuidic devices (105). In an example, the lid of the

microfiuidic apparatus (100) includes both an input port and an output port to allow an anaiyte to pass entirely through the microfiuidic channel (1 15) and away from the co-planar microfluidic devices (105) and out of the microfluidic channel (1 15).

[0021] The diversity of the microfluidic devices (105) allows for a number of different microfluidic apparatus (100) that can receive different analytes and perform different analysis on those analytes. In an example, the microfluidic devices (105) may include optical sensors and/or capacitors with each of the optical sensors including a diverse number of band pass filters to detect different wavelengths of electromagnetic radiation and the capacitors to detect, for example, the ionic properties of the analyte. The microfluidic apparatus (100) that includes these diverse number of band pass filters may defect properties of the analyte via detection of reflected and/or emitted light from the analyte. in this example, the optica! transparence, optical absorption, and/or ionic content of the analyte may be detected.

[0022] In an example, the microfluidic devices (105) may include at least two microfluidic devices (105) that are spaced apparat from each other along the microfluidic channel (1 15) at a certain distance, in this example, a flow viscosity of an analyte passing through the microfluidic channel (1 15) may be detected, in this example, the flow viscosity of the analyte is the distance between the microfluidic devices (105) divided by the time delay when the analyte contacts a first microfluidic device (105) and when the analyte contacts at least a second microfluidic device. Additional microfluidic devices (105) may be included along the microfluidic channel (1 15) such that an average flow viscosity may be calculated based on when the analyte contacts each of the microfluidic devices (105). In an example, as the analyte comes in contact with the first microfluidic device (105), an "analyte in" event may be triggered.

Accordingly, as the analyte touches each of the successive number of microfluidic devices (105), a "fluid pass" event may be triggered. With this information, the viscosity may be calculated as described herein. Because the distance between the first and at least second microfluidic device (105) is decided at manufacture as well as the characteristics of the microfluidic channel (1 15) generally, the viscosity of the analyte may be determined, in an example, the first microfluidic device (105) may also be capable of heating the analyte as the ana!yte passes over the first microfluidic device (105), In this example, the at least second microfluidic device (105) may measure the temperature of the analyte thereby determining the change in temperature as the analyte passes through the microfluidic channel (1 15). This information may be used to determine other characteristics of the analyte besides or in addition to the viscosity of the analyte.

[0023] In an example, the microfluidic devices (105) may include at least two semiconductor laser and sensor microfluidic devices (105). In this example, the analyte may absorb the electromagnetic radiation emitted from the semiconductor laser microfluidic devices (105) and reemit a secondary wavelength of electromagnetic radiation that indicates a certain property of the analyte exists. The number of sensor microfluidic devices (105) may then detect this secondary wavelength of electromagnetic radiation in order to determine the composition of the analyte. This microfluidic apparatus (100) may therefore, detect the presence of quantum dots, dyes, and/or molecules present in the analyte. in an example, this microfluidic apparatus (100) may determine whether a chemical reaction had taken place or to what extent that chemical reaction had taken place upstream of the microfluidic devices (105). Such process may be used in the detection of deoxyribonucleic acid (DNA) sampling and provide further information regarding the (DNA).

[0024] In an example, the microfluidic devices (105) may include a microfluidic devices (105) that prepare an analyte for further analysis, mixing, and/or reaction with another substance. The microfluidic apparatus (100), in an example, may include a permanent or electromagnetic magnets that are embedded co-planarly in the substrate (1 10). In this example, the magnet may be used as a trap for magnetic beads. In some instances, these beads may be prepared and surface activated prior to being introduced into the microfluidic apparatus (100) and/or microfluidic channel (1 15). The activated beads, usually on the scale of microns in diameter, may be used as receptors of certain chemicals or biofiuids in the analyte. The beads may be trapped by the magnets in order to extract a certain chemical or portion of the analyte via elution of the received on the surface of the beads. The portion of the analyte resulting from the elution process may then be carried downstream of the microfluidic devices (105) and microfluidic channel (1 15) for further analysis or manipulation.

[002S] In any of the examples described herein, the microfluidic apparatus (100) may further comprise a redistribution layer (RDL) or any other type of electrical trace layer that provides electrical or signal connectivity between the microfluidic devices (105) and/or to other devices outside of, inside of, or otherwise associated with the microfluidic apparatus (100), in an example, the RDL may be embedded into the substrate (1 10) as well or otherwise made to be co-planar with the microfluidic devices (105). In an example, the RDL is not co-planar with the microfluidic devices (105).

[0026] Each of the microfluidic devices (105) described herein may also provide a functions. In some examples, the microfluidic devices (105) may be a combination of any of the herein-mentioned microfluidic devices (105) that analyze the anaiyte passing through the microfluidic channel (1 15).

Additionally, although the microfluidic devices (105) have been described in connection with being placed within a single microfluidic channel (1 15) formed by a lid, the present specification contemplates the use of a microfluidic channels (1 15) either in series or parallel to each other with each microfluidic channel (1 15) including its own microfluidic devices (105). Still further, the microfluidic apparatus (100) may be in the form of a cassette that interfaces with, for example, a fluid ejection controller, in this example, the fluid ejection controller may be communicatively coupled to the RDLs providing energy and signals to the cassette and microfluidic devices (105) as well as receiving data from the microfluidic devices (105). in an example, the cassette may further include a fluid ejection device that ejects an amount of fluid into, for example, an assay plate after being analyzed by the microfluidic devices (105). in any of the examples, an outside power source such as the fiuid ejection controller may selectively provide power and data signals to the microfluidic devices (105) through the use of a processor. The processor may execute computer readable program code that directs energy and signals to the microfluidic devices (105) in order to, at least, analyze the analyte passing through the microfluidic channel (1 15).

[0027] Fig. 2 is a block diagram of a microfluidic system (200) according to an example of the principles described herein. In this example, the microfluidic system (200) may include a substrate (210) with microfluidic devices (205) embedded therein. As described above, the substrate (210) may be any type of substrate (210) that provides for each of the microfluidic devices (205) to be individually embedded therein, in an example, the substrate (210) is EMC,

[0028] The microfluidic devices (205) may be embedded into the substrate (210) such that each of the microfluidic devices (205) are co-planar with respect to each other. By embedding each of the microfluidic devices (205) co-planariy, fluidic flow of an analyte over the microfluidic devices (205) can be made to be relatively constant but for the properties of the analyte itself. As in the example where the microfluidic devices (205) measure fluidic flow and/or viscosity, the co-planar layout of the microfluidic devices (205) will not alter or disrupt the flow of the analyte over the microfluidic devices (205).

[0029] Examples of the microfluidic devices (205) may include those examples described herein. Each of the microfluidic devices (205) may further be formed such that each of the microfluidic devices (205) execute multiple functions in order to analyze the analyte.

[0030] In an example, the analyte flowing over the microfluidic devices (205) may be contained within a microfluidic channel formed by a lid placed over and parallel to the microfluidic devices (205). In an example, the microfluidic system (200) may include more than one microfluidic channel with each of the microfluidic channels including microfluidic devices (205). in an example, the microfluidic channels may be in series such that an analyte is analyzed by a more than one set of microfluidic devices (205). in an example, the microfluidic channels may be parallel with respect to each other such that an analyte is analyzed by more than one set of microfluidic devices simultaneously or nearly simultaneously.

[0031] As described herein, the microfluidic system (200) may include a cassette housing the microfluidic devices (205) and a fluid ejection controller that controls, at least, the functioning of the microfluidic devices (205), in this example, the fluid ejection controller may include a processor that serves as a signal source and controls energy provided to each of the microfluidic devices (205). Because, in an example, at least one of the microfluidic devices (205) may be a fluid ejection device, the processor of the fluid ejection controller may cause the fluid ejection device to selectively eject an analyte form the cassette and into, for example, an assay plate.

[0032] Fig. 3 is a block diagram of a microfluid fluid analyzer (300) according to an example of the principles described herein. The microfluid fluid analyzer (300) may include at least two microfluidic devices (305) embedded into a substrate (310). Similar to other examples described herein, the microfluidic devices (305) may be embedded into the substrate (310) such that the microfluidic devices (305) are co-planar to each other. Additionally, the substrate (310) may be, in an example, made of EMC.

[0033] The microfluid fluid analyzer (300) may further include a lid (315). The lid (315) may be made of any material that can contain an analyte within a microfluidic channel (320) formed between the interface of the lid (315) and the microfluidic devices (305). In an example, the lid (315) may be made of EMC.

[0034] As described above, the microfluidic devices (305) may be divers among each other in both function and form. In an example, the microfluidic devices (305) may be any number of fluid flow sensors used to measure the flow of an analyte passing through the microfluidic channel (320). These fluid flow sensors may also measure the viscosity of the analyte as it flows through the microfluidic channel (320).

[003S] In an example, the microfluidic devices (305) may be light emitting devices, light sensing devices, or combinations thereof. In an example, at least one of the microfluidic devices (305) may be a combination of a light emitting device and light sensing device. During use of the microfluid fluid analyzer (300), the analyte passing through the microfluidic channel (320) may be excited using a specific wavelength of light emitted by the light emitting device. Any light reemitted from the analyte may be detected by the light sensing device and details about the composition of the analyte may be inferred or determined from that reemitted light. In an example, reactions that should have taken place in the analyte upstream of the microfluidic channel (320) may be detected using the light emitting and light sensing devices.

[0036] In an example, the microfluidic devices (305) may be a number of magnetic devices used to trap a number of ferromagnetic balls within the analyte passing through the microfluidic channel (320). As described herein, these bails may be chemically activated so as to eventually extract a certain chemical or portion of the analyte via elution of the received on the surface of the balls.

[0037] Fig. 4 is a block side cutout view of a microfluidic system (400) according to an example of the principles described herein. The microfluidic system (400) includes at least two microfluidic devices (405) embedded into a substrate (410). As shown in Fig. 4, the microfluidic devices (405) are co-planar with respect to each other with each of an upper portion of the microfluidic devices (405) lying on the same plane. Additionally, the microfluidic devices (405) may each be co-planar to an upper surface of the substrate (410). As described herein, the co-planar nature of the microfluidic devices (405) to each other and/or to the substrate (410) allows for a determinable flow of an analyte through the microfluidic channel (415).

[0038] Again, the microfluidic devices (405) may each be different among each other and in an example, may provide multiple function during operation of the microfluidic system (400). During operation, these microfluidic devices (405) may interact with the analyte as described herein. As the analyte passes through the microfluidic channel (415) in the direction of the dotted line (420), the microfluidic devices (405) may analyze the analyte as described herein.

[0039] As described herein, the microfluidic system (400) may further include a lid (425). The lid (425) may help form the microfluidic channel (415) defined between the substrate (410) with its microfluidic devices (405). In an example, the lid (425) has both an input port (430) and an output port (435). in some examples, an input port (430) may be formed in the lid (425) while an output port (435) is not formed into the lid (425). [0040] Fig. 5 is a block side cutout view of a microfluidic system (500) according to an example of the principles described herein. The microfluidic system (500) may include similar features as those described in connection with Fig. 4. The microfluidic system (500) may include at least two microfluidic devices (405) embedded in a substrate (410) co-p!anar!y. A lid (425) may also be placed over the microfluidic devices (405) with the lid having an input port (430) and an output port (435). The lid (425), input port (430), and output port (435) form a fluid flow path as indicated by the dotted line (420). Additionally, the microfluidic system (500) may include a redistribution layer (RDL) (505) that electrically couples each of the microfluidic devices (405) to each other and to an electrical and/or signal source. The RDL (505) may be coplanar to the microfluidic devices (405).

[0041] The specification and figures describe a microfluidic device, system, and apparatus that includes microfluidic devices embedded into a substrate. The microfluidic devices are each different from each other allowing for an anaiyte to be analyzed as the analyte passes over the microfluidic devices. The microfluidic device, system, and apparatus further includes a lid that is placed over the microfluidic devices thereby forming a microfluidic channel between the lid and the coplanar microfluidic devices. Placing the microfluidic devices in a coplanar manner allows for smooth fiuidic flow from one microfluidic device to the another in the microfluidic device, system, and apparatus. The microfluidic devices are heterogenous with respect to at least one of the other microfluidic devices. Because the heterogeneous microfluidic devices are embedded in the substrate, the cost is reduced allowing for more complexity of microfluidic devices to be embedded into the substrate without the entire substrate being made of silicon. Additionally, the heterogenous microfluidic devices can be embedded into the substrate, each of the

microfluidic devices may be made of different materials thereby further increasing the complexity and functionality of the microfluidic system, device, or apparatus. As a result, a wide array of different life science applications can be realized through the use of the heterogeneous microfluidic devices. [0042] The preceding description has been presented to illustrate and describe examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and variations are possible in light of the above teaching.