Optimal Strategies for Moving Droplets in Digital Microfluidic Systems

In digital microfluidic systems, analyte droplets (volume typically á1μl) are transported on a planar electrode array by dielectrophoretic and electrowetting effects. While recent work has demonstrated feasibility mainly with single droplets on small arrays, these systems hold promise for commercial-scale applications by simultaneously moving many droplets on large arrays. This paper introduces a broadly applicable approach to optimally control digital microfluidic systems, i.e., software algorithms that generate a sequence of control signals for moving one or many droplets from start to goal positions in the shortest number of steps, subject to constraints such as minimum required separation between droplets, obstacles on the array surface, and limitations in the control circuitry.