A Drop-on-Demand-Based Electrostatically Actuated Microdispenser

This paper presents a noncontact drop-on-demand three-layer microdroplet generator based on electrostatic actuation. The dispenser is actuated via a deformable membrane that isolates the electrical field from the working fluid. The dispenser controlled droplet formation, frequency, size, and velocity within the ranges tested. Prototypes were fabricated using three-step deep reactive-ion etching and polydimethylsiloxane (PDMS) plasma activated bonding. Experiments verified stable droplet dispensing with a variance in subsequent droplet volume of less than 15% between droplets. The frequency of stable generation was 20 Hz, and the average volume of dispensed droplet was 1 nL. The dispenser operating range and the nondestructive actuation make it suitable for biological applications.