A novel micropump actuated by NiTi/Si composite diaphragm was described in this paper. The driving principle, microfabrication processes and characteristics of the pump were reported. The pump is composed of a deformable chamber and two silicon flap check valves. The outer dimension of the pump is
6mm×6mm×1.5mm, with the diaphragm size of
3mm×3mm×20μm. The fabrication processes include silicon micromachining and Au
Si eutectic bonding. By using the
recoverable force of NiTi thin-film and biasing force of silicon membrane, the actuation diaphragm realized reciprocating
motion effectively. Experimental results show that the pump has superior performance, such as high pumping yield (up to 340μl/min), high working frequency (up to 100Hz), and long fatigue life time (more than
4×107 working cycles).