Chemical gas sensors suffers from the drawbacks such as high temperature ((>=300oC) and very high power consumption for sensing inflammable gases like CO, CH4 etc. In this work a new technique for thermal isolation in MEMS gas sensors is presented by coupling micromachining of bulk silicon and oxidized macro porous silicon (OMPS) layer to reduce the power consumption. Using oxidized macro porous silicon isolation layer over micromachined silicon substrate complete electrotheral and mechanical design of a simple and effective model of micro-hotplate has been done. Heating element used is Dilver P1 which is an alloy of Fe, Ni, Co. The maximum temperature of 150 oC was achieved a power consumption of 95mW.

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Oxidised Macro Porous Silicon Microheater