Micro-heater filament on polyimide membrane for gas sensor applications

Micro-heater filaments on polyimide membrane for micro gas sensors are fabricated and measured. Resistance as well as power consumption are calculated and temperature of the filament is then extracted. The polyimide membrane is supported by silicon frame that has been etched from the back side by bulk micromachining in a potassium hydroxide (KOH) solution. The filament is made of platinum with a thickness of 300 nm. The membrane thickness is 20 μm. It has an area of 3.5 mm × 3.5 mm and the area covered by the heater filament is 750 μm × 750 μm. The filament shows power consumption of 243 mW at temperature of 115 ^oC.