AM-EWOD array element circuitry with high sensitivity for small capacitance
US10997931B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 2018 |
| Grant date | May 4, 2021 |
| Priority date | — |
| Expiry date | Dec 3, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2330/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An AM-EWOD device includes a plurality of array elements arranged in an array of rows and columns, each of the array elements including array element circuitry, an element electrode, and a reference electrode. The array element circuitry includes actuation circuitry configured to apply actuation voltages to the element and/or reference electrodes for actuating the array element, and impedance sensor circuitry configured to sense impedance at the array element electrode to determine a droplet or device property at the array element, the impedance sensor circuitry comprising a sensor capacitor and a sensor readout transistor that outputs an output current for sensing. The sensor capacitor is electrically connected to a gate of the sensor readout transistor such that during a sensing phase a voltage perturbation is coupled through the sensor capacitor (and possibly other circuit elements) to the gate of the sensor readout transistor. The impedance sensor circuitry further comprises a pre-charging element that operates to turn on the sensor readout transistor during the sensing phase in combination with coupling of the voltage perturbation, thereby increasing the effect of the voltage …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.