Fabrication of a micropellistor with MEMS-Based microhotpalte applying the Technology of Micro-fluidics digitalization

The size of the microhotpaltes based on MEMS is micron-grade, typically rectangular membrane of 270μm×70μm, in micropellistors. Coating catalytic materials on the microhotplate appeared to be an extremely critical step in practice. We report a promising approach for coating catalytic materials on the microhotplate of micropellistors in the paper. A catalytic material coating apparatus was established according to the Technology of Micro-Fluidics Digitalization. In this apparatus, the catalytic materials, finely dispersed Al₂O₃ suspension and platinum palladium catalyst, were ejected out a micro-nozzle by the pulse inertia force produced by a piezoelectric actuator. The micro-nozzle is fabricated by glass heat process and has the advantages of won´t being corroded after being exposed in air for long time, won´t pollute the chemical solution in it and being of low cost. The porous Al₂O₃ matrix thickness and the amount of catalyst can be controlled accurately in this apparatus. The micropellistor with original signal of 75mV was fabricated in this paper and 36m V was remained after aging treatment. The power consumption can remain 75mW as well.