FIELD

[0001] The subject matter described herein relates generally to microfluidic systems and their manufacture, and more specifically the packaging of devices that can interact with small volumes of fluid for the purpose of embedding them within microfluidic systems.

BACKGROUND

[0002] Microfluidic systems are of use for applications where small quantities of fluid need to be manipulated and controlled. Two common applications are 1) for high throughput analysis, where large numbers of small volume experiments are performed; and 2) point of care analysis, where an assay is to be performed on a small liquid sample such as blood or saliva. While microfluidics has shown great promise for these applications, a significant problem exists for the integration of microfluidic functions with other common functions, such as mechanical, optical, and electrical functions. A truly useful system must integrate these disparate functions together into a single device.

[0003] Conventional microfluidic production approaches produce capillary systems in polymer, glass, or other materials using embossing or etch methods. These methods are efficient at producing microfluidic channels, but they are poor for integrating electronics, optics, and mechanical functions into the same system. Usually, these non-fluidic functions are added as external components after the microfluidics have been produced. In some cases, attempts are made to include these functions during the manufacture of the microfluidic channels; however, this results in highly complex and expensive manufacturing processes that are not suitable for large-scale production. Moreover, this process requires that the designer and manufacturer be expert in producing all of the individual parts of a system, such as micro-pumps, micro-valves, micro-heaters, micro-electrodes, micro-sensors, and the like. Figure 1 shows an example of a conventional microfluidic device which comprises a flat substrate 101, typically comprising plastic or glass, with openings 103 to allow fluid to be introduced and extracted from a network of micro-channels 105, or capillaries, whose function is to move fluid from one location to another. Some of the micro-channels 107 are constructed in such a manner to provide additional functionality to the device, such as heating, valving or pumping. These parts are manufactured in the same process as the manufacture of the micro-channels. Most of the fluidic functions are provided externally 109 to the device.

[0004] An alternative approach is to build specific microfluidic parts as small, discrete devices, and then embed these as individual components within a larger microfluidic system. This allows each part to be designed and manufactured separately, increasing quality and reducing production cost. Figure 2 shows an example of a conventional microfluidic device including discrete components. As shown, the microfluidic device comprises a flat substrate 201, typically comprising plastic or glass, with openings 203 to allow fluid to be introduced and extracted from a network of micro-channels 205, or capillaries, whose function is to move fluid from one location to another. Discrete components 207, 209 are attached or embedded within the device in such a manner to access the fluid in the micro-channels and provide functionality. Components, such as, e.g., the component 209, connect with the microfluidic channels, but may also connect with external systems, such as electrical traces 211.

[0005] To embed the components within the larger microfluidic system, the components need to be connected to one or more microfluidic channels, and may require other connections such as electrical, optical, mechanical, or thermal connections. Currently, there is no way to accomplish this in a consistent manner that is compatible with large-scale manufacturing.

SUMMARY

[0006] The various embodiments provided herein are generally directed to a component package that enables a microfluidic device to be fixed to a printed circuit board or other substrate, and embedded within a larger microfluidic system. Microfluidic components enable conventional microelectronic infrastructure and technology to be merged with microfluidic systems. The embodiments presented are herein referred to as a "microfluidic component package" or MFCP.

[0007] In embodiments, a microfluidic component comprises a small device intended to be embedded within a microfluidic system. The component typically comprises one or more ports that allow the component to come in contact with fluid that is routed on a microfluidic layer, and to perform a function that is useful to the operation of the microfluidic system. The device is manufactured by any means that is reasonable. Microfluidic components may perform operations such as micro-pumps, micro-valves, micro-heaters, micro-electrodes, micro-sensors, etc. A microfluidic component package (MFCP) allows a device to be readily integrated with the microfluidic system. [0008] In embodiments, the MFCP is small enough to be mounted on a printed circuit board or other surface. It is comprised of molded polymer which houses or encapsulates one or more microfluidic devices, and has one or more access openings, or ports, to allow fluid to enter the package and interact with the enclosed device. The ports are temporarily sealed to allow the MFCP to be handled and assembled using automation technology during production of the system, but are opened after the MFCP has been embedded within the microfluidic system.

[0009] Other systems, methods, features and advantages of the example embodiments will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description.

BRIEF DESCRIPTION OF FIGURES

[0010] The details of the example embodiments, including structure and operation, may be gleaned in part by study of the accompanying figures, in which like reference numerals refer to like parts. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the disclosure. Moreover, all illustrations are intended to convey concepts, where relative sizes, shapes and other detailed attributes may be illustrated schematically rather than literally or precisely.

[0011] Figure 1 is a schematic of microfluidic system has micro-channels and active parts that operate as valves, pumps, and similar functions. These are all fabricated at the same time, in the same substrate, as the microfluidics.

[0012] Figure 2 is a schematic of microfluidic system that utilizes individual devices that are manufactured separately and then embedded within the system when manufacturing the microfluidics.

[0013] Figure 3 is a cross-sectional view of an exemplary microfluidic component package MFCP with multiple devices and ports, according to embodiments of the present disclosure.

[0014] Figure 4 is a cross-sectional view of MFCP embedded within a microfluidic system and electronic circuit board, according to embodiments of the present disclosure.

[0015] Figure 5A illustrates a first step in an exemplary MFCP embedding process, according to embodiments of the present disclosure.

[0016] Figure 5B illustrates a second step in an exemplary MFCP embedding process, according to embodiments of the present disclosure. [0017] Figure 5C illustrates a third step in an exemplary MFCP embedding process, according to embodiments of the present disclosure.

[0018] Figure 5D illustrates a fourth step in an exemplary MFCP embedding process, according to embodiments of the present disclosure.

[0019] It should be noted that elements of similar structures or functions are generally represented by like reference numerals for illustrative purpose throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the preferred embodiments.

DETAILED DESCRIPTION

[0020] Each of the additional features and teachings disclosed below can be utilized separately or in conjunction with other features and teachings to provide a microfluidic component package and methods of manufacture. Representative examples of the embodiments described herein, which examples utilize many of these additional features and teachings both separately and in combination, will now be described in further detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the disclosure. Therefore, combinations of features and steps disclosed in the following detail description may not be necessary to practice the disclosure in the broadest sense, and are instead taught merely to particularly describe representative examples of the present teachings.

[0021] Moreover, the various features of the representative examples and the dependent claims may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings. In addition, it is expressly noted that all features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original disclosure, as well as for the purpose of restricting the claimed subject matter independent of the compositions of the features in the embodiments and/or the claims. It is also expressly noted that all value ranges or indications of groups of entities disclose every possible intermediate value or intermediate entity for the purpose of original disclosure, as well as for the purpose of restricting the claimed subject matter.

[0022] The various embodiments provided herein are generally directed to a microfluidic component package ("MFCP") that can produce a consistent interface between a small microfluidic device and a larger microfluidic system, while also allowing access to electrical, optical, mechanical, and thermal connections. The MFCP may comprise one or more

microfluidic devices contained within it, and the MFCP is intended to be embedded within a larger microfluidic system.

[0023] Figure 3 shows an exemplary MFCP 300, according to embodiments of the present disclosure. The MFCP 300 comprises an enclosure 301 which may be solid filled or may comprise a hollow interior. The enclosure 301 may be paired with a substrate 303 on one or more sides, for example the bottom, to add additional functionality to the package or to assist in attachment to a larger system. Within the enclosure 301 are one or more microfluidic elements that add functionality to a microfluidic system such as micro-channels 305. In the preferred embodiment, the micro-channels 305 are encapsulated within the package or enclosure 301. One or more ports 309 and 315 may be defined to allow access to the microfluidic elements/micro- channels 305 inside the enclosure 301. A sacrificial material 307 may be used to connect a microfluidic element to the port of the package. The sacrificial material 307 is known to be dissolvable or etchable by a suitable chemical. At a later time, a physical connection can be made from the port to the microfluidic element by first making an opening in the enclosure 301 at the location of the port 309, 315, then removing the sacrificial material 307 by dissolving or etching the sacrificial material 307 away using an appropriate chemical. This provides an opening between the outside of the package and the microfluidic elements 305 inside.

[0024] The enclosure 301 may include cavities 311, and may provide optical openings 313, such as lenses, filters, mirrors, and the like. Ports 315 may be used to provide access to other features of the enclosed device, such as pneumatic, hydraulic, mechanical, or thermal access. Ports may be provided on all sides of the enclosure, including ports 317 through the bottom substrate.

[0025] The enclosure 301 may include elements 319 in addition to microfluidic elements, such as microelectronic devices, including light sources, photosensors, computers, and electronics.

[0026] The enclosure 301 may also include features that allow it to be attached to conventional systems, such as tapped holes 321 for screws or contact pads 323 for soldering the device 300 to a printed circuit board. The contact pads 323 also allow electrical energy to enter and leave the package. [0027] The MFCP may be embedded within any microfluidic system. However, in the preferred embodiment a microfluidic system for embedding the MFCP within comprises a network of microfluidic channels prepared on a printed circuit board.

[0028] Figure 4 shows the preferred method for embedding the MFCP in a larger microfluidic system 400. In this embodiment, a printed circuit board (PCB) 401 is prepared having a solid material and electrical traces for routing electrical signals. The PCB 401 comprises specific contact pads 403 for connecting to a component such as an MFCP 409. Mounting is most commonly performed using solder 405, which connects the contact pads from the PCB 403 with the contact pads 407 on the MFCP 409. The solder connections 405 provide electrical connection as well as mechanical connection.

[0029] The MFCP 409 that comprises the microfluidic and other elements is encapsulated within a material 411 (e.g., polymer). Openings 413 are provided in the encapsulating material (e.g., polymer) 411 to allow fluidic access from a microfluidic channel 415 to the ports of the MFCP 409. Microfluidic channels 415 are fabricated on the encapsulating material (e.g., polymer) 411 forming the larger microfluidic system 400.

[0030] Figures 5A-5D illustrate how an MFCP 501 may be embedded within a printed circuit board and microfluidic system.

[0031] Figure 5A illustrates a first step in an exemplary MFCP embedding process, according to embodiments of the present disclosure. As shown in Figure 5A, the MFCP 501 is mounted on a printed circuit board 503 using technology such as soldering.

[0032] Figure 5B illustrates a second step in an exemplary MFCP embedding process, according to embodiments of the present disclosure. As shown in Figure 5B, an encapsulating polymer 505 is used to cover the MFCP 501 and printed circuit board 503. The encapsulating polymer 505 is embossed or planarized to produce a suitable surface, for example, a flat surface 507.

[0033] Figure 5C illustrates a third step in an exemplary MFCP embedding process, according to embodiments of the present disclosure. As shown in Figure 5C, one or more holes 509 are drilled through the encapsulating polymer 505 to produce openings in the package and expose the sacrificial material 502 within.

[0034] Figure 5D illustrates a fourth step in an exemplary MFCP embedding process, according to embodiments of the present disclosure. As shown in Figure 5D, the sacrificial material 502 is removed by dissolution or etching 511, opening up the microfluidic elements within the package. A microfluidic layer 513 is bonded to the encapsulating material to form a sealed microfluidic system.

[0035] All features, elements, components, functions, and steps described with respect to any embodiment provided herein are intended to be freely combinable and substitutable with those from any other embodiment. If a certain feature, element, component, function, or step is described with respect to only one embodiment, then it should be understood that that feature, element, component, function, or step can be used with every other embodiment described herein unless explicitly stated otherwise. This paragraph therefore serves as antecedent basis and written support for the introduction of claims, at any time, that combine features, elements, components, functions, and steps from different embodiments, or that substitute features, elements, components, functions, and steps from one embodiment with those of another, even if the following description does not explicitly state, in a particular instance, that such

combinations or substitutions are possible. Express recitation of every possible combination and substitution is overly burdensome, especially given that the permissibility of each and every such combination and substitution will be readily recognized by those of ordinary skill in the art upon reading this description.

[0036] In many instances entities are described herein as being coupled to other entities. It should be understood that the terms "coupled" and "connected" or any of their forms are used interchangeably herein and, in both cases, are generic to the direct coupling of two entities without any non-negligible e.g., parasitic intervening entities and the indirect coupling of two entities with one or more non-negligible intervening entities. Where entities are shown as being directly coupled together, or described as coupled together without description of any intervening entity, it should be understood that those entities can be indirectly coupled together as well unless the context clearly dictates otherwise.

[0037] While the embodiments are susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that these embodiments are not to be limited to the particular form disclosed, but to the contrary, these embodiments are to cover all modifications, equivalents, and alternatives falling within the spirit of the disclosure. Furthermore, any features, functions, steps, or elements of the embodiments may be recited in or added to the claims, as well as negative limitations that define the inventive scope of the claims by features, functions, steps, or elements that are not within that scope.