Surface micromachined electrostatic diaphragm micropump

An electrostatic diaphragm micropump for fluids and gases has been designed and fabricated by silicon surface micromachining. Diaphragm structures are bridge-type, cantilever-type and fan-type polysilicon, and sacrificial layers are low-temperature oxide (LTO) on polysilicon substrates. The developed anhydrous HF gas-phase etching of sacrificial oxide on polysilicon substrates has been employed to release polysilicon microstructures. The fabricated micropump with size of the order of 1mm(2) operates at square wave voltage of 10V and 2Hz under near room temperature and normal atmospheric pressure.