具体实施方式：
Methods of Construction and Use of a Microfluidic Channel Network
[0031]Provided in certain embodiments herein are design articles (such as any article described herein) comprising one or more microfluidic channel network in or on (e.g., on the surface of) the design article. In some instances, in order to create large-format microfluidics (e.g., suitable for providing large format design on a design article), one or more microfluidic channel networks is woven through (e.g., through or over the surface of) the item of interest. In one embodiment, large-format microfluidics are accomplished by weaving a small outer diameter tube into a pattern, encasing the patterned tube within an exterior matrix such as a transparent polymer of similar refractive index, and exposing the two ends of the tube outside the matrix for fluidic connection. In another embodiment, multiple tubes are encompassed or woven into or atop the matrix. In some instances, the multiplicity of input ends and of output ends of the tubes are aggregated into domains for fluidic connection. In some instances, such as in some embodiments of apparel or shoes, the microfluidic circuit material is on the order of one to two square feet in size. In other embodiments, however, any suitable sized material is optionally utilized. Provided in certain embodiments herein is a process to seal the dozens to thousands of serpentine wall joints that are useful in creating such a network. In some embodiments, provided herein, are high throughput processes that provide rapid and inexpensive manufacturing of such an article.
[0032]In one embodiment, a first (e.g., lower—or distal from the article surface) material, such as a thermoplastic (e.g., urethane, polyester, etc.), is molded into a serpentine channel network. In some embodiments, the first material (e.g., thermoplastic) is polymerized (at least partially polymerized). In some instances, a second (e.g., upper) material, such as a second thermoplastic, is laminated onto the first material (e.g., applying evenly distributed pressure and heat). In some embodiments, bonding of the composite layers is promoted by means of physical and/or chemical adhesion due to thermal exposure, pressure, adhesives, solvents, surface chemistry activation, polymerization, or a combination thereof. In certain embodiments, the lower thermoplastic is of a harder or softer durometer than the top sealing thermoplastic. In various embodiments, the first and second thermoplastics have any suitable durometer for achieving a desired product. For instance, in some embodiments, the first (e.g., lower) channel material has a 20-30 A durometer with the walls embedded within, while the second material (e.g., upper sealing layer) provides exterior protection with a 25-40 A durometer hardness. In another embodiment, the lower channel material has a harder 25-70 A hardness (e.g., to provide mechanical stability to the walls) while the second material (e.g., top sealing layer) is laminated onto the walls using a 15-30 A durometer material. In yet another embodiment, the first and second (e.g., upper and lower) materials comprise similar or identical materials and/or have similar or identical durometer. In some embodiments, lamination is optionally assisted through the use of roller(s), e.g., machined roller(s) that apply more heat and pressure to the channel walls than to the channel. For instance, FIG. 18 illustrates one embodiment whereby a roller wheel applies heat and pressure selectively to areas of the thermoplastic sandwich to create sealed channel walls. In this embodiment, the connector is first adhered to the circuit inlet and outlet before the entire piece is coated in a transparent encapsulating polymer overmold. In one embodiment, the optional overmold imparts additional sealing and texture as necessary. In one embodiment, microfluidic material is also attached to a backing material to provide mechanical robustness, e.g., to withstand the strain encountered during wear in a shoe. In another embodiment, the backing would be a reflective material, such as a mylar, to impart desired optical properties to the composite. Other possibilities include the use of thermoformed or cold formed foils or foil composites as the patterned channel material and a polyester/polyvinyl chloride, polychlorotrifluoro ethylene, or cyclic olefin copolymer backing.
[0033]In other embodiments, microfluidic channel networks are ultrasonically or RF welded into the thermoplastic sandwich. The upper or lower parts may be previously molded to focus energy to the channel walls. For ultrasonic welding, the preferred frequencies are 10-80 kHz. In the case where a single ultrasonic horn is insufficient to cover the entire desired apparel area, multiple horns can be used. Provided herein are designs that leave a stitching area of 0.5 mm to 5 mm between overlapping horn designs, or any other spacing, e.g., so to allow subsequent precision welding to stitch across the large horn deficiencies. In yet other embodiments, thermoplastic sandwiches are swelled using an ionic bath before electrowelding via current passing between the walls of the upper and lower parts.
[0034]Provided in certain embodiments herein is a design article or design element comprising a microfluidic circuit channel comprising at least one color, angle, density, or the like. In specific embodiments, the design article or design element comprises a single microfluidic channel. In certain embodiments, a single microfluidic channel connecting inlets and outlets is fashioned into multiple virtual panels by alternating the direction and/or density of the filling pattern used. In some embodiments, using a single channel allows for a much wider range of filling pressures without generation of voids. In some instances, if multiple channels are filled in parallel, there is a good chance that high pressure paths will be excluded and fluid will preferentially flow through low pressure paths—much like an electrical short will carry current around an electrical circuit. The current design for filling a large area with a single channel to create multiple channels eliminates this problem. Per example shown in FIG. 19, a single microfluidic circuit with one inlet and one outlet, with various angles and densities of fill create the illusion of separate panels when filled with one or more colors.
[0035]Provided in certain embodiments herein is a design article or design element comprising a microfluidic circuit in three-dimensions. In some embodiments, a three-dimensional microfluidic circuit overlays serpentine channel arrays at varying depths of the article to create intricate visual effects (e.g., texture, patterns, color fields, etc.) as seen from surface of the article. In some embodiments, a three-dimensional microfluidic circuit consists of a single or of multiple layers of channels and is shaped to the three-dimensional form of the article (e.g., shoe, electronics case, etc.). In one embodiment, a three-dimensional microfluidic circuit is accomplished by generating a sealed planar microfluidic circuit in a flexible substrate (e.g., urethane) and affixing this microfluidic circuit conformally to a three-dimensionally formed article. In certain embodiments, the microfluidic circuit is affixed by means of pressure-sensitive adhesive. In some embodiments, bonding between the microfluidic circuit and article is promoted by means of physical and/or chemical adhesion due to thermal exposure (e.g., welding, laminating, etc.), pressure, adhesives, solvents, surface chemistry activation (e.g., UV-ozone exposure), polymerization (e.g., reaction injection molding), mechanical fastening, or a combination thereof. In other embodiments, the three-dimensional microfluidic circuit is formed via additive manufacturing (e.g., selective laser sintering, fused deposition modeling, stereolithography, 3D printing, etc.). In one embodiment, the final sealed microfluidic circuit is formed by laying down successive layers of material with a 3D printer to form the channel walls. Zones that have not been printed upon create the internal channels of the final microfluidic circuit. In other embodiments, the three-dimensional microfluidic circuit is formed via direct subtractive manufacturing (e.g., laser etching, lost-wax casting, investment casting, etc.) in which the microfluidic channels are formed by the removal of material from within the article. In one embodiment, a three-dimensional article is formed in polycarbonate and internal laser etching is used to remove material to create the microfluidic channels.
Methods of Construction and Use of a Manually Actuated Docking Station
[0036]Provided in certain embodiments herein is a docking station comprising a pump, color cartridges and connector (collectively, the “cartridge”) that connects to the corresponding connector integrated into the microfluidic circuit and allows the user to manually actuate the initiation and duration of flow through the microfluidic circuit. FIG. 20 is an example of a manually actuated docking station with an integrated connector. In some embodiments, the docking station is comprised of a fluid cartridge 2001 and a waste cartridge 2002. The user would pull back on the plunger assembly 2003 to actuate the ratcheted syringe 2004 and create a vacuum within waste compartment 2002. In one embodiment, an absorbent material, such as hydrogels, is contained in the waste cartridge 2002 to prevent spillage or backflow. As the vacuum is created, the syringe nub 2005 moves to displace the colored fluid. The syringe nub 2005 also serves to keep the fluid sealed from the environment during storage. As the ratcheted syringe 2004 is pulled back, it can be finely tuned for some length until the ratchet teeth move past the ratchet cap 2006, wherein the syringe can no longer be pushed forward. The ratcheting ensures that the cartridge is used only a few times before recycling. The male connector 2007 interfaces with the female connector 2008, shown here embedded within a mobile phone case, with an embedded microfluidic channel network 2009, shown in cross sectional and planar view.
[0037]In another embodiment of a manually actuated docking station with an integrated connector, as shown in FIG. 21, the connector is comprised of a freely rotating screw ring 2101 snapped onto the connector body that allows the user to form a strong fluidic seal. The connector also has tapered ports that mate to the corresponding tapered item connector 2103 through an interference fit. The interference between the tapered ends helps complete a sound fluidic seal.
[0038]In yet another embodiment, there is a utility to provide for simultaneous connection of two fluid lines to simplify user interactions. FIG. 22 is an example of a self sealing dry break connector with integrated microfluidic inlet and outlet fluid paths. In this embodiment, the male connector housing 2201 contains a screw 2202 that pushes against a sealing ring 2203 that, when extended, closes off the fluid lines 2204 of the connector. The female counterpart has a screw thread 2205 that aligns the male connector, a sealing cap 2206 and associated screw 2207 that when disconnected, shuts off flow in the female fluid lines 2208. Unique to this design is the minimal dead volume resulting from the microfluidic lines being small enough to feed through the threading of the screw. Further, the spring, or other force element, loaded sealing cap 2206 provides a means to wipe clean the female fluid lines of dried fluid during connecting and disconnecting. This same self cleaning happens on the male side from screw thread 2205.
[0039]In other embodiments, the ease of connection is facilitated through magnetic forces. FIG. 23 embodies magnetic connectors with integrated microfluidic inlet and outlet fluid paths. In this embodiment, a spring 2301, upper cap 2302 and upper seal 2303 are housed within upper body element 2304. When disconnected, the spring 2301 closes off the fluidic path 2305 by pressing the upper cap assembly up against the magnet 2306. An actuator pin 2307 with embedded fluidic channels passes through stud 2308, which is further coupled to an O-ring 2309 to provide for a firm fluidic seal when connected. In some embodiments, when placed in close proximity to the bottom half of the connector, the upper magnet 2306 couples with the steel (or other ferritic or magnetic material) 2310 embedded in the lower base 2311. This magnetic force simultaneously couples the upper and lower halves of the connector, and through action of the actuator pin, displaces lower seal 2312 and follower 2313 against spring 2314, which are housed in the lower base 2315. This balance of forces opens the fluidic path 2316, and completes the fluidic circuit. In this embodiment, when disconnected, the springs (or bushings, pneumatic elements, etc.) press the seals back into place and create a dry break seal. In alternative embodiments, timing is added to the connector, wherein the actuator pin moves the valve into the open position while the connection is being made to avoid backpressure from the female side. In such an embodiment, shortly after the initiation of connection, the stud would seal the fluidic path via an O-ring, then pushes the female seal open.
[0040]In certain embodiments, a manually actuated docking station carries a plurality of fluid compartments to actuate flow within a plurality of microfluidic circuits, e.g., a two color cartridge could swap out the contents of two different microfluidic channel circuits simultaneously. In other embodiments, one connector per microfluidic circuit is arranged on the item, for example in FIG. 24, which gives an example of multiple stacked circuits and multiple connectors within a single item. In some embodiments, two microfluidic circuits are embedded within the vertical extent of a mobile phone case. A mobile device 2401 is placed within case housing 2402 and pressed up against the case backing 2403. On the backside of the case, microfluidic circuits 2404 and 2405 combine to form a checkerboard pattern. When different colors are sequentially pulled through the circuit, the combination of colors produces a unique user defined case. In certain embodiments, there are separate connectors for each circuit, in this case, connector 2406 would allow access to microfluidic channel 2405 while connector 2407 would allow access to microfluidic circuit 2404. In addition, in some embodiments, each connector would be sealed when not in use by a thumb screw cap 2408.
Online Distribution of Content Codes
[0041]Provided in certain embodiments herein is a system for providing the design to any design element described herein. In some embodiments, provided herein is a system for configuring the design of a design element comprising a microfluidic circuit, the system comprising a module configured to set a color sequence for filling the microfluidic circuit with one or more colored fluid. In various other embodiments, the system comprises any additional module suitable for providing a design, or a particular design to the design element. For example, in some embodiments, a system described herein comprises a module configured to set the flow rate or pressure of fluid filled into the microfluidic channel. Further, in certain embodiments, any system described herein further comprises a module configured to access a remote server comprising color sequence, flow rate, and/or pressure information for configuring the design of the design element; a module configured to detect the type of design element comprising the microfluidic circuit; one or more module configured to adjust the color sequence, flow rate of fluid, and/or pressure of fluid; or the like. Similarly, the system optionally comprises a module configured to achieve any of the processes or results described below.
[0042]In one embodiment, a Code is resolved by a central server to point to a reference file (HTML, XML, etc) that has all the information (the Code file format) that would include color patterns, fluid pressure filling instructions (timing, pressure, duty cycle, color sequence, fluid channel orientation), pictures used to augment your apparel, brands that you incorporate into the outfit, and meta-tags to define and classify the contents. Codes can be made malleable across different apparel through the use of progressive algorithms, i.e., given the apparel microfluidic channel map, the algorithm would describe one or more optimal filling patterns with the color sequence of choice. For instance, the user could be presented with a first, algorithmically optimized preview of the apparel. The user could then choose to modulate the color pattern using high level tools, such as applying filters to the apparel (rotating, horizontal stripes, vertical stripes, gradients, or other 2-D kernels). These Codes could be applied within a social network like Facebook, a PC or mobile platform app that allows people to share or modulate your latest Codes instantaneously (i.e., what I'm wearing to school today) and has a suggestion engine that can proffer different outfits based on the user's historical taste and recent self-expression. In one embodiment, suggestions could be updated with up-to-the minute crowdsourced data, and people can follow celebrities, designers, TV shows, etc., to get Codes for fashion.
[0043]Online Codesharing can tap into retail or online databases to suggest apparel combinations based on brand, local availability, online availability, complementary colors, etc. Retailers can purchase space on the Codestore to promote codes with their products. Codes can also be suggested based on hierarchical demographics, described by trends or styles (goth, sexy, preppie, classic, tasteful, etc.).
[0044]Codecasts, like podcasts, would allow people to download other designers' codes, follow celebrities, etc. The Code file format also allows users to purchase specialized codes for 99 cents.
[0045]In some embodiments, the system comprises any suitable processor, e.g., a central processing unit, or collection of processors comprising the modules described herein. In certain embodiments, provided herein is a sub-system comprising any one or more modules described herein that may be used in conjunction with any one or more other sub-system to achieve the results of the system described herein.
[0046]Certain embodiments of the present invention relate to the modulation of appearance or material properties within items such as apparel (e.g., footwear, shoes, belts, backpacks, hats, bracelets, wristbands, shirts, jewelry, glasses, materials for apparel, release papers, fibers, etc.), equipment (e.g., skateboards, rollerblades, snowboards, gloves, hockey pads, appliances, computers, electronics, gadgets, toys, etc.), and other three-dimensional objects (signs, corporate art, corporate logos, military vehicles, military gear, helmets, vehicle body panels, housewares, furniture, tabletops, walls, paintings, etc.). In some embodiments, provided herein is an item (e.g., an article of apparel, an article of sporting equipment, or the like) comprising a fluidic channel (e.g., a microfluidic channel containing therein a liquid, particularly a colored liquid). In specific embodiments, the fluidic channel is a part of a fluidic circuit that further comprises an inlet and an outlet, wherein the inlet and the outlet are connected by the fluidic channel. Moreover, some embodiments of the present invention relate to fluidic manipulation of appearance and/or material properties and modulation thereof, including a microfluidic circuit, inlets and outlets to the fluidic system, and a docking system to deliver fluid to the item.
[0047]Certain embodiments herein provide an item comprising a microfluidic circuit to allow modulation of appearance or material properties of the item (FIG. 1). One or more microfluidic circuits in the shape of swooshes, stripes, ribbing along the outlines of a design, logos, background elements, etc. can be integrated into an item (FIG. 2). Microfluidic circuits may also encompass a large portion of the item, and in some cases substantially comprise the outer extent of the item; for instance in belts, skateboards, helmets, corporate logos, motorcycle panels, etc. In preferred embodiments provided herein, microfluidic circuits comprise an inlet, an outlet and a translucent or transparent microchannel (i.e., at least a portion of the microchannel is translucent and/or transparent) system, through which fluids can flow (FIG. 3). Microfluidic channel structures (including the fluidic channels and walls between channels) provided herein may cover up to 100%, up to 90%, up to 80%, up to 70%, up to 60%, up to 50%, up to 40%, up to 30%, up to 20%, up to 10%, or up to 5% of an item's surface. Microfluidic channel structures may cover 1-100%, 1-10%, 10-95%, 1-50%, 10-50%, 20-50%, 20-100%, 30-100%, or any other suitable amount of an item's surface.
[0048]Provided in certain embodiments herein a design article provided for herein comprises a microfluidic circuit integrated into or onto the surface thereof. In specific embodiments, the microfluidic circuit is integrated into or onto the external surface of the article. In certain embodiment integrated microfluidic circuits or molds comprising microfluidic circuits are attached to an underlying portion of the article surface (e.g., sewn thereto, glued thereto, etc.), or comprise a part of the surface itself (e.g., no underlying surface of the article is necessary). In some embodiments at least one segment (which term is used synonymously herein with a portion of the microfluidic circuit; and is not intended to necessarily denote any substructure of the microfluidic circuit) of the microfluidic circuit is exposed to the external surface of the apparel or equipment. Further, in some embodiments, the at least one transparent or translucent wall segment is exposed to the surface of the apparel or equipment, providing for visual contact between the surface of the apparel or equipment and the microfluidic channel (i.e., the fluid, or component parts thereof, can be seen from the exterior of the article). In certain embodiments, up to 100%, up to 90%, up to 80%, up to 70%, up to 60%, up to 50%, up to 40%, up to 30%, up to 20%, up to 10%, or up to 5%, 1-100%, 1-10%, 10-95%, 1-50%, 10-50%, 20-50%, 20-100%, 30-100%, or any other desired amount of the external surface or wall of the microfluidic circuit comprises a translucent or transparent material.
[0049]Provided in further embodiments herein is a method of manufacturing an article of apparel or equipment having alterable design features, the method comprising:
[0050]integrating a microfluidic circuit into or onto the surface of the article, the microfluidic circuit comprising a microfluidic channel, an inlet and an outlet, and the microfluidic channel having at least one segment in visual contact with an external surface of the article.
[0051]In some embodiments, provided herein is a method of modulating the appearance or material properties of an article of apparel or equipment comprising:
[0052]moving fluid through a microfluidic circuit integrated with the apparel or equipment and having at least one segment in visual contact with an external surface of the apparel or equipment, the microfluidic circuit comprising a microfluidic channel, an inlet and an outlet, with the microfluidic channel connecting the inlet to the outlet within the article.
[0053]In a first embodiment, one or a plurality of microfluidic circuit(s) are integrated into the exterior of an item of footwear. In one embodiment, the inlet and outlet of the microfluidic circuit are contained within a port hidden within the back heel of the shoe. In such an example, connection to the docking station allows the user to change the color of the exterior of the shoe to match the desired color. In certain embodiments, the microfluidic circuits are configured to cover 75% of the exterior of the shoe, for instance the channels can be integrated into the synthetic leather upper, the tongue of the shoe, and the sole. In other embodiments, the microfluidic circuits are configured to cover 25% of the exterior of the shoe, for instance against a white leather shoe, the microfluidic circuits comprise the stylized logos and decorative ribbing alongside the circumference of the shoe. In yet other embodiments, the micro fluidic circuits are configured to comprise 100% of the upper exterior of the shoe, having been integrated directly into the polyurethane or polyvinyl chloride release papers that then form the pad and the strap of a high heel shoe. In yet another embodiment, the microfluidic circuits are fashioned into 10% of the exterior of the shoe, molded to cover the straps on a pair of sandals. In another embodiment, the microfluidic circuits are integrated into the substructure of a shoe, covered by a porous material, such as a canvas or cotton to allow color to be seen through the gaps of the material. In yet other embodiments, combinations of microfluidic circuits offer multiple ways to expressing oneself, e.g., stiff polycarbonate microfluidic circuits prominently displayed on 50% of the exterior of the shoe with another 15% of the shoe covered in a soft polyurethane microfluidic circuit that covers the toe box and circumvents the shoelace holes. In certain embodiments, the microfluidic circuits are fabricated from polyurethane. In others, the microfluidic circuits are fabricated from polyvinyl chloride, poromerics, pleathers, Clarino, polycarbonate, or other synthetic leather materials.
[0054]In addition to the appearance of an item, the microfluidic circuit may also transport various fluids throughout the extent of the item to modulate the material properties of the item. For instance, in addition to the appearance, exchange of fluids within the microfluidic circuit may modulate the touch, feel, stiffness, or roughness of the item. In one embodiment, a metal microparticle sol may optionally displace an aqueous suspension of small molecule dyes to randomly distend a soft microfluidic circuit (for instance, made of lightly crosslinked polyurethane), which would simultaneously create raised reflective bumps along the skin of the item in place of the previous smooth, homogeneous and brightly colored surface. In another embodiment, a purple, heated, lavender scented polyethylene glycol solution with a large heat capacity is optionally pumped through the base of a shoe to displace a cold metal microparticle solution in order to modulate the thermal properties and rigidity of the shoe. In yet another embodiment, microfluidic circuits are molded into an article of clothing for a toy doll, in which a color (e.g., bright green) is optionally replaced by a magnetic glitter, that allows other magnetic components to be attached to the toy's apparel.
[0055]Other material properties that may be altered by transport through the micro fluidic circuit include optical properties (e.g., color, reflectivity, absorption), scent, thermal properties (e.g., heat capacity, heat transfer coefficient), mechanical properties (e.g., stiffness, roughness, pressure), electromagnetic properties (e.g., paramagnetic, ferromagnetic, conductive), therapeutic properties, or chemical properties (e.g., fluorescent, chemiluminescent) of the item.
Valves Between Connector & Item
[0056]In certain embodiments the openings (e.g., inlets to and/or outlets from) the microfluidic circuit contain valves. In such embodiments, input and output valves can be constructed from septum valves, check valves, ball valves, multi-port valves, microfluidic valves, pinch valves, and so forth. In one preferred embodiment, microfluidic circuit valves are comprised of a polyphenylenesulphone (PPSU), nitrile butadiene rubber (NBR), and polyimide (PI) passive dynamic check valve. In various embodiments, the valve may have any suitable dimension, e.g., roughly 2×0.5 mm in dimension. Further, in various embodiments, the valve may have any suitable structure and/or connection to the fluidic channel, e.g., be embedded within a stainless steel tube of roughly 2×17 mm with an internal volume of 2-5 nL. Valves used in the circuits described herein may deliver any suitable volume of fluid to the circuit. For example, in an embodiment, such as described above, a preferred valve may deliver 0.10-0.30 mL/s at a forward pressure of 7.25 psi. In certain embodiments, the normally closed valves are optionally coupled with a filter. In other embodiments, one or each valve is optionally a normally closed solenoid valve that is actuated by electrical signals carried by the connector to allow flow to various design elements on the item. In such an embodiment, one fluid line from the docking station is optionally split into a plurality of microfluidic circuits within the port of the item, and flow to each design element mediated by the aforementioned active valves.
[0057]In certain embodiments, the valves are optionally protected from wear by housing them in a port, e.g., a protective port, such as a hard plastic port (FIG. 4, FIG. 5). The port is optionally recessed within a shoe, for instance, hidden within a cutout of the sole, within the backing of the heel, or any other suitable location. The port can also be fabricated such that it facilitates simple insertion and alignment to the docking station connector, through molded guides, ramps, snaps, levers, male/female grooves, etc. FIG. 6 demonstrates an example of a connector that simultaneously interfaces to, and opens, the microfluidic circuit valves. In embodiments that use check valves, the increase in pressure from the docking station would open the valves in the item. Other embodiments that use simple septum valves would use a connector with pins that would push past the seal and enter the fluid lines in the item.
[0058]In certain embodiments, the valves are fluidically isolated on a parallel shunt channel or reservoir to prevent leaks while connecting and disconnecting. The shunt channel or reservoir may be separated from the primary microfluidic circuit by passive check valves to create a lower pressure fluidic region for the port connection. Following successful connector to port connection, upon application of fluid pressure the shunt channel opens to full fluid flow through to the microfluidic circuit.
Materials & Construction of Microfluidic Circuits
[0059]The microfluidic circuit of the items described herein (e.g., apparel) can be constructed of any suitable material. In certain embodiments, the structure of the microfluidic circuit or microfluidic channel comprises void (containing a fluid, or into which a fluid may flow) enclosed (e.g., with walls, with at least one opening) by any suitable material or combination of materials. In some embodiments, the microfluidic circuit or channel is constructed of (wholly or in part) a transparent plastic such as polyurethane, polyvinyl chloride, polymethylmethacrylate, cellulose acetate butyrate, polycarbonate, glycol modified polyethylene terephthalate, polydimethylsiloxane, as well as other transparent or translucent plastics suitable for apparel and/or sporting equipment. The microfluidic circuit can be comprised of a rigid, semi-rigid molded part, or in other embodiments, flexible molded parts. In one embodiment of a mold & seal process, two halves of the microfluidic circuit are injection molded and partially cross-linked, prior to alignment and sealing. Alignment of the two halves can be facilitated by the use of automated jigging that moves partially cured items from the molding machine into place, holds a top piece using vacuum pressure, then presses the two halves into one. In various embodiments, sealing comprises and/or is achieved via the use of pressure, heating, acid, UV light exposure, UV-ozone exposure, waiting to allow the partially cross-linked halves to bind to each other as polymerization reactions move towards completion, or the like. In other embodiments, sealing comprises application of an adhesive (chemical adhesive, multi-part epoxy, light-curable compounds, or soaking in acid etc.) between the two layers before applying pressure, heat, UV light exposure or time. Other methods of construction optionally include a process where a positive molding of a channel lumen is constructed using a soluble solid (either water soluble like sugars, starches, cellulose, etc., or soluble in an gentle organic solvent that will not perturb the two halves of the circuit), and is then placed i