Direct current pulse train actuation to enhance droplet control in digital microfluidics

Abstract

The effective operation of a digital microfluidic (DMF) device depends on its ability to actuate droplets. Pulse width modulation of actuating signals (DC pulse train actuation) is proposed as a practical digital implementation and enhanced droplet manipulation technique. Experimental and simulation results demonstrate the efficacy of droplet incremental displacement and velocity control by modulating the width of each actuation pulse. This will in turn enable the control of the non-linear droplet transport dynamics to minimize droplet position overshoot, deformation, and fragmentation. As a result, DCPT actuation offers unparalleled control over droplet position and speed in DMF devices.