Latched transistor driving for high frequency AC driving of EWoD arrays
Inventors
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Assignees
Member
NucleraNuclera develops automated benchtop platforms and integrated systems for rapid protein expression, optimization, and purification, utilizing cell-free synthesis, digital microfluidics, and software-driven workflows. Their technology enables miniaturized and scalable protein prototyping—including challenging targets such as membrane proteins—directly at the lab bench. Nuclera serves academic and industrial researchers, focusing on reducing turnaround time for functional protein access and streamlining screening and production. The company has secured significant funding to enable broad commercialization, expanded their leadership team to support scale-up, and continues to drive advancements in drug discovery, proteomics, and experimental automation.
Nuclera develops automated benchtop platforms and integrated systems for rapid protein expression, optimization, and purification, utilizing cell-free synthesis, digital microfluidics, and software-driven workflows. Their technology enables miniaturized and scalable protein prototyping—including challenging targets such as membrane proteins—directly at the lab bench. Nuclera serves academic and industrial researchers, focusing on reducing turnaround time for functional protein access and streamlining screening and production. The company has secured significant funding to enable broad commercialization, expanded their leadership team to support scale-up, and continues to drive advancements in drug discovery, proteomics, and experimental automation.
Publication Number
US-12027130-B2
Publication Date
2024-07-02
Expiration Date
Abstract
Methods and systems for driving an active matrix electrowetting on dielectric device including thin-film-transistors to increase the switching frequency of the propulsion electrodes beyond what is typical for line-by-line active matrix driving. By using a latching circuit, it is possible to selectively switch specific propulsion (pixel) electrodes between an “on” and an “off” state, wherein a propulsion electrode in an “on” state can be driven by a time varying drive voltage on the top electrode that is a much higher frequency than is typically possible with amorphous silicon thin-film-transistor arrays. The faster drive frequency improves the performance of electrowetting devices, especially when used with aqueous droplets having a high ionic strength.
Core Innovation
Methods and systems for driving an active matrix electrowetting on dielectric device including thin-film-transistors to increase the switching frequency of the propulsion electrodes beyond what is typical for line-by-line active matrix driving are provided. By using a latching circuit, it is possible to selectively switch specific propulsion (pixel) electrodes between an "on" and an "off" state, wherein a propulsion electrode in an "on" state can be driven by a time varying drive voltage on the top electrode that is a much higher frequency than is typically possible with amorphous silicon thin-film-transistor arrays, and the faster drive frequency improves the performance of electrowetting devices, especially when used with aqueous droplets having a high ionic strength.
The background identifies that traditional line-at-a-time active matrix addressing and low mobility a-Si TFTs limit achievable frame rates, and that DC or low frequency AC signals allow ions to diffuse through top dielectric layers leading to electrochemical reactions, device failure mechanisms, and slow-down during low frequency driving. It also identifies that memory-in-pixel approaches that allow high frequency operation are expensive to fabricate, reduce yield, and are not suitable for large-area AM-TFT panels.
The invention provides an AM-EWoD system in which each pixel electrode is connected to a pixel transistor whose gate is operably connected to a latching circuit that can latch the pixel transistor in an on state or an off state controlled by matrix gate and matrix source lines, and after the desired gate pattern is latched the top plane common electrode is used to drive the entire pixel array at once so that only the latched on pixels are driven. This latched transistor driving accommodates higher EWoD frame rates using persistent latched TFTs and a top plane electrode driver capable of driving the top plane electrode at high frequency while enabling implementation with simple design, standard low mobility a-Si TFTs.
Claims Coverage
The independent claims include two main independent claims and seven inventive features are extracted below.
Latching circuit configured to latch pixel transistor via matrix gate and source lines
A latching circuit operably coupled to the pixel gate, a matrix gate line, a matrix source line, and a matrix power rail, the latching circuit being configured to latch the pixel transistor in an on state or an off state controlled by a state of the matrix gate line and a state of the matrix source line.
Pixel transistor connected to pixel electrode and matrix power rail with storage capacitor
Each pixel comprises a pixel electrode and a pixel transistor having a pixel source operably connected to the pixel electrode, a pixel drain operably connected to a matrix power rail, and a capacitor for storing voltage.
Matrix gate and source drivers operably coupled to gate and source lines
A plurality of matrix gate drivers, each operably connected to a matrix gate line, and a plurality of matrix source drivers, each operably connected to a matrix source line.
Top plane common electrode providing a time-variable voltage
A top plane common electrode disposed in opposition to the pixel array, the top plane common electrode operably connected to a top plane common electrode driver and configured to provide a time-variable voltage.
Controller configured to receive instructions to latch pixel transistors
A controller operably coupled to each matrix gate driver, each matrix source driver, and the top plane common electrode driver, the controller being configured to receive instructions from the processing unit to latch the pixel transistor in an on state or an off state.
Receiving input instructions relating to a droplet operation
Receiving input instructions by the processing unit, the input instructions relating to a droplet operation to be performed by the AM-EWoD.
Outputting gate/source signals and time-variable top common electrode signal to drive latched pixels
Outputting matrix gate line and matrix source line selecting instructions from the processing unit to the controller, outputting a matrix gate line signal and a matrix source line signal from the controller to switch the latching circuit of at least one pixel, and outputting a time-variable top common electrode signal from the controller to the top plane common electrode driver to drive latched on pixels.
The independent claims center on an AM-EWoD system and method combining (1) a pixel architecture with a pixel transistor, storage capacitor, and a latching circuit operable via matrix gate and source lines, (2) matrix gate/source drivers and a top plane common electrode providing a time-variable voltage, and (3) controller and processing unit operations to latch pixel transistors and drive latched on pixels.
Stated Advantages
Increase switching frequency of the propulsion electrodes beyond what is typical for line-by-line active matrix driving.
Faster drive frequency improves the performance of electrowetting devices, especially when used with aqueous droplets having a high ionic strength.
Latched driving accommodates higher EWoD frame rates using persistent latched TFTs with simple design and standard low mobility a-Si TFTs, achieving similar results to high-frequency memory-in-pixel techniques at limited extra cost.
Higher-frequency driving results in less slippage of droplet position during droplet protocols.
Amorphous silicon TFTs are much lower cost than LTPS and are suitable for large area manufacture so that large area yield is not an issue.
Documented Applications
Digital microfluidic (DMF) devices used to propel, split, and join droplets in a confined environment ("lab-on-a-chip").
Sample preparation, assays, and synthetic chemistry performed with small volumes.
Mass parallel assays and reactions enabled by active matrix electrode arrays.
Manipulation and processing of droplets containing biological samples, including whole blood, serum, plasma, urine, and other listed biological fluids.
Use with reagents and biochemical protocols including nucleic acid amplification protocols, affinity-based assays, enzymatic assays, gene sequencing protocols, and protein sequencing protocols.
Synthesis of oligonucleotides and related biochemical synthetic methods.
Interested in licensing this patent?