US Patent 11554374 Spatially variable dielectric layers for digital microfluidics

A digital microfluidic device including an active matrix of propulsion electrodes controlled by thin-film-transistors. The device includes at least two areas of different propulsion electrode densities. One area may be driven by directly-driving the propulsion electrodes from a power supply or function generator. In the first, higher density region; a first dielectric layer covers the propulsion electrodes. The first dielectric layer has a first dielectric constant and a first thickness. In the second, lower density region, a second dielectric layer has a second dielectric constant and a second thickness covering the propulsion electrodes.