DIGITAL MICROFLUIDICS DEVICES AND METHODS OF USE THEREOF
20230219094 · 2023-07-13
Inventors
- Jorge Abraham SOTO-MORENO (San Francisco, CA, US)
- Gregory Arthur RAY (San Francisco, CA, US)
- Foteini CHRISTODOULOU (San Francisco, CA, US)
Cpc classification
B01L3/502792
PERFORMING OPERATIONS; TRANSPORTING
B01L2300/168
PERFORMING OPERATIONS; TRANSPORTING
B01L2300/165
PERFORMING OPERATIONS; TRANSPORTING
B01L2200/147
PERFORMING OPERATIONS; TRANSPORTING
B01L7/52
PERFORMING OPERATIONS; TRANSPORTING
B01L2300/1894
PERFORMING OPERATIONS; TRANSPORTING
B01L2200/04
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
Digital microfluidic (DMF) apparatuses and methods for optically-induced heating and manipulating droplets are described herein. DMF apparatuses employing photonic heating as described herein provide radical simplification of routing droplets/reagents in complex, multistep protocols and/or highly plexed workflows.
Claims
1. (canceled)
2. A microfluidic apparatus, comprising: a seating region configured to seat a cartridge thereon, wherein the cartridge comprising a first air gap within which one or more droplets is moved; a vacuum sub-system configured to secure the cartridge in the seating region; a plurality of light-absorbing regions thermally coupled to a plurality of regions of the seating region; a plurality of light emitters separated from the seating region by a second air gap, wherein each light emitter is configured to emit light into the second air gap to heat one or more of the light-absorbing regions; and a controller configured to control the light emitted by each of the light emitters to regulate a temperature of each of a plurality of regions within the first air gap of the cartridge seated in the seating region.
3. The apparatus of claim 2, further comprising a plurality of thermally conductive vias coupling the plurality of light-absorbing regions to the plurality of regions of the seating region.
4. The apparatus of claim 2, further comprising a plurality of thermal sensors configured to provide thermal data to the controller.
5. The apparatus of claim 4, wherein each thermal sensor of the plurality of thermal sensors are configured to detect a temperature of one or more of the light-absorbing regions, a thermally conductive via or an upper surface of the seating region.
6. The apparatus of claim 4, wherein each thermal sensor of the plurality of thermal sensors is paired with a light emitter of the plurality of light emitters.
7. The apparatus of claim 2, wherein each light emitter of the plurality of light emitters comprises one or more of: one or more LEDs or optical fibers.
8. The apparatus of claim 2, wherein the plurality of light emitters are each configured to emit light having a wavelength at least in part from 800 nm to 1000 nm.
9. The apparatus of claim 2, further comprising a focalizer configured to direct each of the plurality of light emitters to selectively illuminate at least one region of the plurality of light-absorbing regions.
10. The apparatus of claim 2, wherein each of the light-absorbing regions of the plurality of light-absorbing regions is configured to convert absorbed light energy to thermal energy.
11. The apparatus of claim 2, wherein the plurality of light-absorbing regions comprises black soldermask or graphite heat-spreading material.
12. The apparatus of claim 3, wherein the plurality of light-absorbing regions are disposed in selected regions around each of the plurality of thermally conductive vias.
13. The apparatus of claim 3, wherein one or more of the plurality of thermally conductive vias each comprise a thermally conductive metal or polymer.
14. The apparatus of claim 4, wherein the controller comprises a microprocessor configured to adjust power applied to the light emitters based at least in part on feedback from the plurality of thermal sensors.
15. The apparatus of claim 2, further comprising a cooler within the second air gap.
16. The apparatus of claim 15, wherein the cooler comprises: one or more fans configured to push cooling gas along a lower surface of a first support within the second air gap; one or more negative pressure sources configured to draw cooling gas along the lower surface of the first support; or a compressor configured to push cooling gas along the lower surface of the first support.
17. The apparatus of claim 15, wherein the cooler comprises an electrostatic fluid generator configured to ionize particles in the second air gap to enable air movement.
18. A microfluidic apparatus, comprising: a first support having an upper surface, a lower surface and a thickness therethrough, the upper surface comprising a seating region for holding a cartridge, a light-absorbing material disposed on the lower surface, and a plurality of thermally conductive vias disposed between the lower surface and the upper surface and passing through the thickness, the plurality of thermally conductive vias configured to heat a droplet disposed in a cartridge seated on the seating region of the upper surface of the first support; a plurality of light emitters and a plurality of thermal sensors disposed on a second support that is adjacent to the lower surface of the first support, wherein each of the plurality of light emitters is configured to illuminate one or more locations of the light-absorbing material on the lower surface of the first support; and wherein the first support and the second support are separated by a temperature-regulating air-gap between the lower surface of the first support and an upper surface of the second support.
19. The apparatus of claim 18, wherein each one of the plurality of light emitters is paired with one of the plurality of thermal sensors, wherein each thermal detector of the plurality is configured to detect a temperature of the one or more locations on the lower surface of the first support illuminated by a respective paired light emitter of the plurality.
20. A microfluidic apparatus, comprising: a first support having an upper surface and a lower surface; wherein the upper surface comprises a seating region for holding a microfluidics cartridge; wherein the lower surface comprises a plurality light-absorbing regions; wherein each light absorbing region is thermally coupled to one or more regions of the upper surface by one or more thermally conductive vias; a plurality of light emitters disposed beneath the first support and separated from the first support by an air gap, wherein each light emitter of the plurality of light emitters are configured to emit light into the air gap to heat one or more light-absorbing regions; a plurality of thermal sensors; and a controller configured to receive input from each thermal sensor of the plurality of thermal sensors and to control the light emitted by one or more of the plurality of light emitters to regulate a temperature of one or more of the one or more regions of the upper surface.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] The novel features of the invention are set forth with particularity in the claims that follow. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
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DETAILED DESCRIPTION
[0056] In general, described herein are digital microfluidic (DMF) apparatuses that include a plurality of DMF drive electrodes that further include one or more thermally controlled region that at photonically heated and may be actively or passively cooled; the photonic heating may be performed from within the device.
[0057]
[0058] Illumination of regions 103, 105 of the light-absorbing region 117, transfer the thermal energy obtained from the illumination, to the thermally conductive vias 141, 143. The thermal energy is transferred from the first end of the thermally conductive vias 141, 143 to the second end of the vias adjacent to the actuation electrodes 142, 144 at the surface 113. The thermal energy is transferred to droplet 145 and heats it.
[0059] The apparatus includes a specific arrangement that permits illumination (light energy) to be provided selectively to location(s) on the light-absorbing region 117 of the lower (e.g., bottom) surface of the support 110. A second support 120, which may be a PCB, is disposed, having an upper surface 123, facing the lower surface 115 of the first support 110 with a temperature-regulating air-gap between. The temperature-regulating air-gap 130 may have a vertical dimension between surface 123 and surface 115 greater than 280 micrometers, greater than 300 micrometers, >400 micrometers, >500 micrometers, >600 micrometers, >700 micrometers, >800 micrometers, >1000 micrometers or more. In some variations, supports 110, 120 are coupled together to fix the temperature-regulating air-gap distance. Disposed upon the upper surface 123 of the second support 120 is a plurality of light-emitters 131, 133, 135. The light-emitters 131, 133, 135 may be LEDs, fiber optic fibers, or any suitable light-emitter. In some variations, the plurality of light-emitters may be generated from a single light source and split to emit light at the plurality of positions 131, 133, 135. The light-emitters may emit light in any desired wavelength range, e.g., from about 250 nm to about 100 nm. In some variations the light-emitters may emit light having a wavelength of about 800 nm to about 100 nm, or may emit light which, at least in part, emit light having a wavelength of about 800 nm to about 100 nm. In some variations, broad spectrum lights may be utilized, as generating a large amount of energy in one frequency can reduce efficiencies of transmission and absorption. The light-emitters 131, 133, 135 may be configured to illuminate one or more regions located on the light absorbing layer 117. For example, light-emitter 133 is configured to illuminate one or both of regions 103, 105 of the light-absorbing region 117, adjacent to thermally-conductive vias 141, 143. In some variations, the light-emitter 133 may include a pointing mechanism to direct the emitted light to one of several different locations. In some variations, the light-emitter 133 may be selectively activated to illuminate only one of regions 103, 105. Additionally, only one of light-emitters 131, 133, 135 may be selectively activated to emit light or any combination of light-emitters may be activated at the same time.
[0060] Thermal sensors 132, 134, 136 are disposed on the surface 123, and are disposed adjacent to each of a light-emitter 131, 133, 135 and may be paired to detect the thermal energy from the one or more regions illuminated by its respective paired light-emitter. For example, thermal detector 134 may detect the thermal energy, such as the black radiation in the infrared (non-visible) region of light, which can determine temperature from regions 103 and/or 105 of the light absorbing layer 117. Since the thermally conductive vias 14, 143 are conductive, the temperature of the droplet may be determined and controlled. The thermal sensors may be included in a closed-loop feedback system in order to control the temperature of the droplet 145.
[0061] The DMF apparatus may further include components configured to cool the first support, e.g., the support having the droplet manipulation surface. Many protocols and workflows require a period of heating followed by a period of cooling, which may be repeated for any number of cycles.
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[0064] In general, the methods and apparatuses described herein are DMF apparatuses that may include photonic heating as part of the control system for controlling localized temperature control of one or more (preferably a plurality of) DMF regions, such as regions within an air gap in which one or more droplets may be moved the DMF apparatus. Any appropriate DMF apparatus may be configured and/or operated as described herein to include photonic hating. For example, the apparatuses (systems, devices, etc.) described in PCT/US2020/02025, filed on Feb. 28, 2020, and herein incorporated by reference in its entirety, may include photonic heating as described herein.
[0065] For example,
[0066] For example, the vacuum sub-system may include a vacuum chuck, a vacuum pump, and one or more pressure sensors for detecting (and/or providing feedback to control the vacuum) pressure. The software subsystem may include software, hardware or firmware, such as a non-transitory computer-readable storage medium storing a set of instructions capable of being executed by the one or more processors of the controller to coordinate operation of the systems, including any of the sub-systems. The thermal subsystem may include the TECs, heat sinks/fans, and one or more thermal sensors (including thermal sensors configured to monitor temperature of the cartridge, e.g., the air gap region and/or one or more thermal sensors configured to monitor the temperature of/within the housing, of the TECs, etc.). The magnetic subsystem may include, for example, one or more magnets (such as one or more Halbach array magnets), one or more actuators for all or some of the magnets and one or more position sensors for monitoring/detecting the positon of a magnet (e.g., a home sensor).
[0067] The housing may be connected to, and/or may partially enclose one or more inputs and/or outputs 611, such as a display and input subsystem 629. The display may be a touchscreen and/or one or more buttons, dials, etc.
[0068] An electrode sub-system may include the array of drive electrodes (e.g. an electrode array) underlying the cartridge seat, one or more high-voltage drivers, one or more TEC driver, a safety interlock, one or more resistive heaters, etc.
[0069] The lid may couple to the housing and may at least partially enclose the lid subsystem, as mentioned above. The lid sub-system may include, for example, one or more pipette pumps, a vacuum manifold, one or more solenoid valves, one or more pressure sensors, one or more positional sensors, and one or more indicators (e.g., LEDs, etc.). The lid may be hinged to close over the cartridge and against the housing; this lid (and the cartridge clamp) may, separately, lock over the cartridge when it is loaded into the reader, and may be hinged to the housing. As mentioned, the cartridge clamp may be coupled to the housing and may be covered by the lid.
[0070] As descried herein the apparatus (e.g., the “reader”) may include a thermal subsystem 621 that may include a plurality light-absorbing regions thermally coupled to a plurality of regions of the seating region (cartridge set 602) and a plurality of light emitters separated from the seating region by an internal air gap. Each light emitter may be configured to emit light into the air gap to heat one or more of the light-absorbing regions.
[0071]
[0072] In
[0073] Although the example apparatus shown in
[0074] In operation, any of the apparatuses described herein may be used to process a droplet, or multiple droplets either in parallel (e.g., at the same time) and/or sequentially. For example,
[0075] The method may include illuminating a selected location of the lower surface of the first support. This selected location may include a light-absorbing region configured to receive light energy. The region may be illuminated by any appropriate light source, across an air gap region 703. The light emitted may be absorbed by the light-absorbing material and converted into heat 705. Examples of light-absorbing materials are provided herein, and may be coordinated with the applied wavelength, so that light is absorbed in a specific wavelength or range of wavelengths. In some variations different regions may include different light-absorbing materials that may absorb at different wavelengths. The light sources may then be controlled to emit specific wavelengths to heat select regions that match the emitted wavelength(s).
[0076] The heat generated by absorbing the light energy may then be transmitted through the support to the upper side by one or more thermally conductive vias. For example, the heat may be transmitted by a thermal via to a location on the upper surface of the support 707, thereby heating a droplet in thermal contact with this region/portion of the upper surface.
[0077] In some variations the droplet may be moved into a heated region. Alternatively or additionally, a droplet may be moved from the heated region to a second region that is not heated or a second region that is heated to a different temperature.
[0078] These methods may also include cooling one or more regions. For example, the air gap region between the support and a second support holding the light sources may be cooled (e.g., by a fan, etc.) as described above.
[0079] Any of the steps of these methods may also include monitoring the temperature of one or more of: the thermally conductive region, the thermally conductive via, and/or the thermally regulated region 709. The sensed temperature may then be provided as feedback to the controller that may adjust one or more of: the applied light, (turning it on/off or increasing/decrease the amount of light emitted), and/or cooling (e.g., a fan, negative pressure source, compressor, etc.). Thus the controller may regulate the temperature of the one or more regions.
[0080] Any of the apparatuses described herein may include an array of heaters and thermal sensors throughout the underside of the PCB (see, e.g.,
[0081] The availability of “on demand” heaters across the surface of the DMF PCB as described herein may radically simplify the routing of droplets/reagents in complex, multistep protocols or high-plex operations. More specifically, these methods and apparatuses may give the path finding algorithm, which may schedule and determine which components get manufactured most broadly freedom to route reagents focusing solely on reagent cross-contamination rules without having to consider HW limitations such as a fixed positions of TEC heaters under the DMF PCB. With this flexibility the DMF cartridge can offer an on-demand a large number of independently controlled thermally-regulated regions (e.g., each corresponding to, e.g., 96 or 384 reaction well plate equivalent (for plexing reactions) or host complex, multistep workflows such as: cell culture followed by either transfection/transformation or cell-->cell based assay.fwdarw.cell isolation-->cell lysis-->library preparation for NGS or target molecule detection end point reactions (such as RT-qPCR or qPCR).
[0082] When a feature or element is herein referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.
[0083] Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”.
[0084] Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.
[0085] Although the terms “first” and “second” may be used herein to describe various features/elements (including steps), these features/elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed below could be termed a second feature/element, and similarly, a second feature/element discussed below could be termed a first feature/element without departing from the teachings of the present invention.
[0086] Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising” means various components can be co-jointly employed in the methods and articles (e.g., compositions and apparatuses including device and methods). For example, the term “comprising” will be understood to imply the inclusion of any stated elements or steps but not the exclusion of any other elements or steps.
[0087] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and/or position to indicate that the value and/or position described is within a reasonable expected range of values and/or positions. For example, a numeric value may have a value that is +/−0.1% of the stated value (or range of values), +/−1% of the stated value (or range of values), +/−2% of the stated value (or range of values), +/−5% of the stated value (or range of values), +/−10% of the stated value (or range of values), etc. Any numerical values given herein should also be understood to include about or approximately that value, unless the context indicates otherwise. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also understood that when a value is disclosed that “less than or equal to” the value, “greater than or equal to the value” and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value “X” is disclosed the “less than or equal to X” as well as “greater than or equal to X” (e.g., where X is a numerical value) is also disclosed. It is also understood that the throughout the application, data is provided in a number of different formats, and that this data, represents endpoints and starting points, and ranges for any combination of the data points. For example, if a particular data point “10” and a particular data point “15” are disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 are considered disclosed as well as between 10 and 15. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.
[0088] Although various illustrative embodiments are described above, any of a number of changes may be made to various embodiments without departing from the scope of the invention as described by the claims. For example, the order in which various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments one or more method steps may be skipped altogether. Optional features of various device and system embodiments may be included in some embodiments and not in others. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims.
[0089] The examples and illustrations included herein show, by way of illustration and not of limitation, specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived there from, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.