An Electrowetting Pump

ABSTRACT

Fluid pumping underpins technologies from microfluidics to soft robotics. Solid‐state pumps generate flow without moving parts, eliminating the noise and vibration typical of conventional pumps. We present here a 1 mm‐diameter tubular pump based on electrowetting on dielectric (EWOD) that transports droplets in a stepwise manner, providing accurate, reversible, and silent flow. By patterning electrodes on the tube's exterior, we leverage electrostatic forces to manipulate conductive droplets while avoiding deleterious electrochemical reactions. The pump achieves droplet speeds of 125 mm s ^{− 1} , flow rates up to 4.8 mL min ^{− 1} , and pressures of 0.1 kPa per droplet, operating reliably for well over 10 000 cycles. The pump wall can be fabricated from rigid or flexible materials. We show integration into textiles and on soft structures, illustrating the potential for controlling fluid flow in wearables. Electrowetting pumps represent a new class of thin, solid‐state fluidic actuators for wearable, medical, and soft robotic applications.