Authors: A.D. Johnson, V. Martynov, V. Gupta and L. Menchaca
Affilation: TiNi Alloy Company, United States
Pages: 222 - 225
Keywords: micropump, modular, silicon oxide, TiNi, thin film
A new micropump mechanism has been created that consists of two silicon/silicon oxide dies with vias and dome-shaped membranes. The membranes are bonded face-to-face to form variable-volume domed liquid chambers. The membranes increase and decrease in volume in response to external forces. By sequencing the modulations, fluid is pulled into the first chamber, transferred to a second chamber, and expelled from the apparatus. There are no valves per se, but backflow is prevented by action of the membranes. The pump has no sliding or rotating parts, only parts that change shape. The actuator described here is a sputter deposited shape memory TiNi thin film that has a stroke of 100 microns with a force of 0.4 Newtons and is powered by an electric current at voltages compatible with microelectronics. The pumps can also be actuated by means of pressure/vacuum systems.