Characteristics and fabrication of NiTi/Si diaphragm micropump

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 6 mm x 6 mm x 1.5 mm, with the diaphragm size of 3 mm x 3 mm x 20 mum. 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 340 mul/min), high working frequency (up to 100 Hz), and long fatigue life time (more than 4 x 10(7) working cycles). (C) 2001 Elsevier Science B.V. All rights reserved.