Non-contact acceleration and deceleration of flying micro droplets

We developed a noncontact technique to accelerate and decelerate in-flight microdroplets emitted by inkjet technology. The technique involves the application of a localized dielectrophoretic force to the droplets, and the momentum applied to a droplet is as large as 10−12 N s, which is adequate for accelerating a droplet of 10 μm radius such that its velocity increases by 0.3 m/s. Highly selective control of the continuously emitted droplets was achieved with a temporally modulated electric field. The method is effective for insulating liquid droplets and is applicable for the microfabrication processes in the air.