Droplet analysis is increasingly becoming used to test small samples (e.g., droplet) of fluid to determine its biological and/or chemical characteristics. Such a droplet may be introduced to a fluid processing chip (e.g., integrated circuit chip) that processes the droplet to determine if the droplet includes various chemicals and/or biological material. In some instances, the droplet may be mixed with one or more other chemicals before analysis by the fluid processing chip.
The disclosure relates to manipulation of a droplet via an electrowetting force. Examples include a device that may include an insulator panel, a plurality of electrical inputs, and a plurality of electrodes. The plurality of electrical inputs may be disposed on the insulator panel and individually receive an actuation voltage. The plurality of electrodes may be disposed on the insulator panel and are coupled to the plurality of electrical inputs. Two or more of the plurality of electrodes may be coupled to a single one of the plurality of electrical inputs for each of the plurality of electrical inputs. The plurality of electrodes may be actuated with the actuation voltage individually received at a respective electrical input to create an electric field over associated electrodes to subject a droplet proximate to the associated electrodes actuated with the actuation voltage to an electrowetting force. Electrowetting involves modifying the surface tension of a liquid on a solid surface using a voltage. As a result, the actuation voltage may be applied to a single electrical input that creates an electric field over numerous electrodes. In some examples, some of the electrodes may be coupled to input pads that receive samples of fluid, with at least a portion of the samples of fluid being subject to an electrowetting force with the plurality of electrodes. In other examples, the droplet may be moved to a sensor for analysis.
The device may allow for a reduction in a number of electrical inputs into a chip that includes the device, providing for improved scaling for large number of parallel operations, smaller overall chip area, a simpler control system, and higher reliability. The device may employ a reduced number of electrical inputs to control electric fields over a plurality of electrodes that are utilized to subject a droplet to an electrowetting force. This is in contrast to other devices that employ a one-to-one relationship between a number of electrical inputs and a number of electrodes.
The device 100 may further include a plurality of electrodes 110a-f disposed on the insulator panel 125. The plurality of electrodes 110a-f may be coupled to the plurality of electrical inputs 105a-c. At least two of the plurality of electrodes 110a-110f may be coupled to a single one of the plurality of electrical inputs 105a-c, respectively. The plurality of electrodes 110a-f may be actuated with the actuation voltage individually received at the plurality of electrical inputs 105a-c to create an electric field over the plurality of electrodes 110a-f actuated with the actuation voltage to subject a droplet 120 proximate to at least one of the plurality of electrodes 110a-f actuated with the actuation voltage to an electrowetting force.
The plurality of electrodes 110 may be disposed approximately in a straight line to form a main passageway 210 of electrodes 110 from one end of the device 200 to another end of the device 200. The droplet 120 may move to any of the electrodes 110 that make up the main passageway 210. The electrodes 110 may include a repeating sequence of three or more electrodes 110 comprised of “A”, “B”, and “C” electrodes. This main passageway 210 of electrodes 110 may include the repeating sequence of “A”, “B”, and “C” electrodes. An actuation voltage may be applied to electrical input 105a. This actuation voltage at electrical input 105a may actuate all of the “A” electrodes to exert an electrowetting force on a droplet 120 proximate to the “A” electrodes. An actuation voltage may be applied to electrical input 105b. This actuation voltage at electrical input 105b actuates all of the “B” electrodes to exert an electrowetting force on a droplet 120 proximate to the “B” electrodes. An actuation voltage may be applied to electrical input 105c. This actuation voltage at electrical input 105c actuates all of the “C” electrodes to exert an electrowetting force on a droplet 120 proximate to the “C” electrodes. Coordinated actuation of the electrodes 110 may result in the droplet 120 moving between electrodes 110, merging with other droplets, splitting of the droplet 120, and mixing of droplets (e.g., mix components within at least two droplets). When the droplet 120 is being moved between two adjacent electrodes 110 (e.g, from the “A” electrode to the “B” electrode), only the electrode that the droplet is being moved to is actuated with the actuation voltage. That is, the electrode 110 that the droplet 120 is being moved from and adjacent to the electrode 110 that the droplet 120 is being moved to is at a second voltage state that is sufficiently lower than the actuation voltage to setup the electrowetting force. In contrast to other devices that employ a one-to-one relationship between a number of electrical inputs and a number of electrodes, the device 200 may include a plurality of electrodes 110 coupled to a single electrical input 105, reducing a number of electrical inputs into a chip that includes the device 200, providing for improved scaling for large number of parallel operations, smaller overall chip area, a simpler control system, and higher reliability.
For example, actuating “A”, “B”, and “C” electrodes sequentially may move the droplet 120 from “A” electrodes to “C” electrode. Repeating this sequence of individually actuating “A”, “B”, and “C” electrodes results in the droplet 120 moving to the right along the main passageway 210 of electrodes 110. Likewise, reversing this sequence by individually actuating “C”, “B”, and “A” electrodes sequentially moves the droplet 120 in a reverse direction along the main passageway 210 to the left.
The main passageway 210 of electrodes 110 from one end of the device 200 to another end of the device 200 may further include “S” sync electrodes. The “S” sync electrodes may all be coupled to electrical input 205e. In an example, electrical inputs 105 and 205 may be 300×300 um in dimension. An actuation voltage applied to electrical input 205e may actuate all of the “S” sync electrodes. The “S” sync electrodes may act as gatekeepers for the droplet 120 in that they control whether the droplet 120 may move from one portion of the plurality of electrodes 110 that make up the main passageway 210 of electrodes 110 to another portion of the plurality of electrodes 110 that make up the main passageway 210 of electrodes 110 unless an actuation voltage is first applied to electrical input 205e to first pull the droplet 120 onto at least one of the “S” sync electrodes. For example, if the droplet 120 is disposed on electrode 110g, the droplet 120 may not move to electrode 110h unless the “S” sync electrodes are actuated by an actuation voltage being applied to electrical input 205e, and vise versa, to pull the droplet 120 onto the “S” electrode between them. Thus, actuation of any of the “A”, “B”, and “C” electrodes between any two de-actuated “S” sync electrodes may result in manipulation of a droplet 120 between such “S” sync electrodes while preventing the droplet 120 from passing a point in the main passageway 210 of electrodes 110 where the “S” sync electrodes are positioned.
The device 200 may further include a plurality of electrodes 110 that form one or more latches 230 that branch off of the main passageway 210. Although the latches 230 are shown as running parallel with the main passageway 210, such an orientation may be utilized to minimize an area utilized to form the device 200. In another example, the latches 230 may be perpendicular to the main passageway 210 or at an angle less than perpendicular to the main passageway 230. In an example, a majority of droplet manipulation (e.g., merging, splitting, mixing) may be performed in the latches 230 to allow the main passageway 210 to remain unblocked. In an example, the device 200 may include six (6) latches 230a-f, with each latch including eight (8) electrodes 110. Actuation of “A”, “B”, and “C” electrodes sequentially may move the droplet 120 into the latches 230. To control entry of the droplet 120 into and out of the latches 230 and within the latch 230, each of the latches 230 may include an electrode 110 designated as an “E” electrode at a point where the latches 230 branch off of the main passageway 210 and an “E” electrode positioned between two strings of three (3) electrodes 110 with the latch 230. The “E” electrodes may all be coupled to electrical input 205b. Thus, an actuation voltage applied to electrical input 205b may actuate all of the “E” electrodes. The “E” electrodes may act as gatekeepers for the droplet 120 in that the droplet 120 may not move from the main passageway 210 of electrodes 110 to the plurality of electrodes 110 that make up the latches 230 unless an actuation voltage is first applied to electrical input 205b to pull the droplet 120 onto the “E” electrodes first. For example, if the droplet 120 is disposed on electrode 110i, the droplet 120 may not move to electrode 110h unless the “E” electrodes are actuated by an actuation voltage being applied to electrical input 205b, and vise versa, to pull the droplet 120 onto the “E” electrode between them. Thus, actuation of any of the “A”, “B”, and “C” electrodes within the latches 230 may result in manipulation of a droplet 120 within the latch 230 while preventing the droplet 120 from moving back to the main passageway 210 until an actuation voltage is first applied to electrical input 205b to pull the droplet 120 onto the “E” electrodes first. Likewise, the droplet 120 may not move from one half of the latch 230 to another half of the latch 230 until an actuation voltage is first applied to electrical input 205b to pull the droplet 120 onto the “E” electrodes first. Other latches 230 may utilize other electrodes 110 to act as gatekeepers. In an example, other latches may utilize “D” electrodes that are all coupled to electrical input 205a, with all of the “D” electrodes being actuated when an actuation voltage is applied to the electrical input 205a.
Latch 230a may be designated as “LatchE A” as latch 230a utilizes an “E” electrode as a gatekeeper and branches off of an “A” electrode from the main passageway 210. Latch 230b may be designated as “LatchE B” as latch 230b utilizes an “E” electrode as a gatekeeper and branches off of a “B” electrode from the main passageway 210. Latch 230c may be designated as “LatchE C” as latch 230c utilizes an “E” electrode as a gatekeeper and branches off of a “C” electrode from the main passageway 210. Thus, although latches 230a-c may utilize an “E” electrode as a gatekeeper, each of the latches 230a-c may be offset with respect to each other in that the combination of electrodes 110 to enter such latches is different. Latch 230d may be designated as “LatchD A” that may utilize an electrode 110 designated as a “D” electrode as a gatekeeper and branches off of an “A” electrode from the main passageway 210. Latch 230e may be designated as “LatchD B” as latch 230e utilizes a “D” electrode as a gatekeeper and branches off of an “B” electrode from the main passageway 210. Latch 230f may be designated as “LatchD C” as latch 230f utilizes a “D” electrode as a gatekeeper and branches off of a “C” electrode from the main passageway 210. Thus, although latches 230d-f may utilize a “D” electrode as a gatekeeper, each of the latches 230d-f may be offset with respect to each other in that the combination of electrodes 110 to enter such latches is different. The device 200 may utilize three electrical inputs 105a-c to control all of the “A”, “B”, and “C” electrodes, two latch inputs 205a and 205b to control the movement of the droplet 120 through all of the latches 230a-f, and n/2 sync electrodes, where n is a number of input pads 220. Thus, for the device 200 that includes four (4) input pads 220, the device may utilize two (2) sync electrodes S1 and S2.
For example, to merge two droplets within the latch 230, two droplets are moved to electrodes 110 speared by an empty electrode 110, for example “A” and “C” electrodes, utilizing either the “D” electrode or the “E” electrode or an “S” electrode. The “B” electrode is actuated with an actuation voltage to merge the two droplets. The merged droplet may be moved back and forth between the “A” and “B” electrodes to mix the merged droplet. The droplet 120 may be split by applying an actuation voltage to electrodes on either side of an electrode 110 on which the droplet 120 is disposed on. For example, if droplet 120 is disposed on the “B” electrode, the droplet 120 may be split by actuating both the “A” and “C” electrodes approximately simultaneously to pull portions of the droplet 120 on both the “A” and “C” electrodes.
The device 200 may further include a plurality of input pads 220. As an example, the device 200 may include four input pads 220. The input pads 220 may be electrodes 110 that exert electrowetting forces on the droplet 120. In an example, each of the input pads 220 may be a point at which a unique fluid is introduced to the device 200. The droplet 120 may be pulled from a larger volume of fluid that is placed on the input pad 220 via an electrode 110 adjacent to the input pad 220. The droplet 120 may be moved to input pad 220 where the droplet 120 may be combined with fluid already on the input pad 220. Nearest input pads 220 on either side of the main passageway 210 may span a distance L1. In an example, L1 may be 1 mm. Input pads 220 on a same side of the main passageway 210 may span a distance L2 from their center point. In an example, L2 may be 2.34 mm. The input pads 220 may include one or more sensors or actuators to analyze or modify the droplet 120 (e.g., a surface for enhanced Raman spectroscopy (SERS), a heater to perform polymerase chain reaction (PCR), etc.). In another example, such one or more sensors or actuators may be coupled to at least one of the latches 230.
Access into and out of input pads 220 on one side of the main passageway 210 may be controlled by electrodes 110 designated as “S1” electrodes. The “C” and “B” electrodes may be disposed between the “S1” electrode and the input pads 220 on the one side of the main passageway 210. Access into and out of input pads 220 on another side of the main passageway 210 may be controlled by electrodes 110 designated as “S2” electrodes. The “C” and “B” electrodes may be disposed between the “S2” electrodes and the input pads 220 on the another side of the main passageway 210. All of the “S1” electrodes may all be coupled to electrical input 205c and may all be actuated with an actuation voltage being applied to electrical input 205c Likewise, all of the “S2” electrodes may all be coupled to electrical input 205d and may all be actuated with an actuation voltage being applied to electrical input 205d.
The device 300 may include chip-to-chip electrodes 330a and 330b. The chip-to-chip electrodes 330a and 330b may be actuated via a corresponding electrical inputs 305a and 305b, respectively. The chip-to-chip electrodes 330a and 330b may move the droplet 120 (or combinations of droplets) between the one chip 310 and the another chip 320. In an example, the chip-to-chip electrodes 330a and 330b may include one or more sensors or actuators to modify to analyze or modify the droplet 120 (e.g., a surface for enhanced Raman spectroscopy (SERS), a heater to perform polymerase chain reaction (PCR), etc.).
In the example shown, the device 300 includes multiple copies of the device 200 to create a length L4. In an example, the length L4 may be approximately 14.35 mm. Each of the chips within the device 300 may have a length L3. In an example, the length L3 may be approximately 28.7 mm.
As illustrated, the individual actuation sequence of electrodes 110 to move the droplet 120 into and out of the latches 230 may be dependent on the latch type that the droplet 120 is being moved into and out of. That is, depending if the droplet 120 is being moved into and out of either the “LatchE A”, “LatchE B”, “LatchE C”, “LatchD A”, “LatchD B”, or “LatchD C” latches, the sequence of electrode 110 actuation may differ accordingly. For example, the “LatchE A” latch may include the “A”, “E”, “B” electrode sequence to move the droplet 120 into this latch, the “LatchE B” latch may include the “B”, “E”, “C” electrode sequence to move the droplet 120 into this latch, the “LatchE C” latch may include the “C”, “E”, “A” electrode sequence to move the droplet 120 into this latch, the “LatchD A” latch may include the “A”, “D”, “B” electrode sequence to move the droplet 120 into this latch, the “LatchD B” latch may include the “B”, “D”, “C” electrode sequence to move the droplet 120 into this latch, and the “LatchD C” latch may include the “C”, “D”, “A” electrode sequence to move the droplet 120 into this latch.
To place the droplet 120 next to one of the “S” sync electrodes, the “A”, “B”, and “C” electrodes may be individually actuated in sequence or in reverse sequence, accordingly. The “A”, “B”, and “C” electrodes may be individually actuated in sequence two times with the “S” sync electrodes and “D” electrodes grounded to return a non-latched droplet adjacent to an “S” sync electrode location on the device 200. Such sequencing may not move the droplet 120 once the droplet 120 is positioned next to one of the “S” sync electrodes until the “S” sync electrodes are actuated. Thereafter, the “S” sync electrodes may be actuated to move the droplet 120 onto the “S” sync electrodes and thereafter into the latch 230.
The latch access chart 400 also shows actuation sequences for other electrodes 110 of the device 200 that may be actuated simultaneously while the droplet 120 is being moved into and out of a desired latch 230. Should there be other droplets disposed on the device 200 while the droplet 120 is being moved into and out of a desired latch 230, those other droplets may be moved proximate to a starting position and return to their starting position once the droplet 120 is moved into and out of a desired latch 230. Thus, the other droplets may be prevented from moving into and out of their respective latches while droplet 120 is moved into and out of a desired latch 230. Movement of the other droplets will be explained in more detail in
As show in the latch access chart 400 and the example movement of the droplet 120 shown in
During movement of the droplet 120 from position 251 to position 252, electrodes 110 in other latches may be sequentially individually actuated also. For example, the electrodes 110 in the “LatchD B” latch may be sequentially individually actuated as follows while the droplet 120 is being moved into the “LatchD A” latch: “Bs”, “D1”, “Bs”, “Bs”, and “As” . For example, the electrodes 110 in the “LatchD C” latch may be sequentially actuated as follows while the droplet 120 is being moved into the “LatchD A” latch: “Cs”, “D1”, “D1”, “Cs”, and “Cs”. During the movement of the droplet 120 from position 252 to position 251, electrodes 110 in other latches may be sequentially individually actuated also. For example, the electrodes 110 in the “LatchD B” latch may be sequentially individually actuated as follows while the droplet 120 is being moved out of the “LatchD A” latch: “B1”, “B1”, “B1”, “B1”, and “A1”. For example, the electrodes 110 in the “LatchD C” latch may be sequentially individually actuated as follows while the droplet 120 is being moved out of the “LatchD A” latch: “C1”, “C1”, “B1”, “B1”, and “A1”.
For example, should another droplet be positioned at a “B” electrode at position 253 while droplet 120 is positioned at position 251 to be moved into the “LatchD A” latch, that other droplet may return to a same electrode 110 position once droplet 120 has completed its sequence into the “LatchD A” latch. As illustrated in
Each of the input pads 220 shown in
In view of the foregoing structural and functional features described above, a method in accordance with various aspects of the present disclosure will be better appreciated with reference to
What have been described above are examples of the disclosure. It is, of course, not possible to describe every conceivable combination of components or method for purposes of describing the disclosure, but one of ordinary skill in the art will recognize that many further combinations and permutations of the disclosure are possible. Accordingly, the disclosure is intended to embrace all such alterations, modifications, and variations that fall within the scope of this application, including the appended claims.
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. What have been described above are examples. It is, of course, not possible to describe every conceivable combination of components or methods, but one of ordinary skill in the art will recognize that many further combinations and permutations are possible. Accordingly, the invention is intended to embrace all such alterations, modifications, and variations that fall within the scope of this application, including the appended claims. Additionally, where the disclosure or claims recite “a,” “an,” “a first,” or “another” element, or the equivalent thereof, it should be interpreted to include one or more than one such element, neither requiring nor excluding two or more such elements. As used herein, the term “includes” means includes but not limited to, and the term “including” means including but not limited to. The term “based on” means based at least in part on.
Filing Document | Filing Date | Country | Kind |
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PCT/US2017/028799 | 4/21/2017 | WO | 00 |