Fabrication of fluid control microdevices

Fluid control microdevices such as microvalves, micropumps, and micromixers are key components in microfluidic systems. Femtosecond laser direct writing of glass followed by wet chemical etching (i.e., femtosecond-laser-assisted wet chemical etching) allows freely movable structures that are internally encapsulated inside microfluidic devices to be fabricated by a single continuous process. Such structures can function as fluid control microdevices that can be used to control the flow rate and direction of fluids in microfluidic channels. This chapter describes fabrication of a freely movable microplate and microrotor whose motions are controlled by air pressure, optical force, or an external micromotor. The microplate functions as a microvalve, whereas the microrotor functions as a micropump.