Thick and thermally isolated Si microheaters for microfabricated preconcentrators

520 μm thick Si microheaters with air gap isolation were fabricated for preconcentrators using optimized etch conditions. A 500 μm wide air gap between the heater and the bonding area improved the thermal isolation. Better thermal isolation was also obtained by etching trenches on the supporting glass substrate before bonding to the microheaters. 25% less power and a 50% faster response time were measured by using air gaps around the microheaters. In addition, 35% power reduction was achieved by operating the microheaters in a 1.2 Torr ambience. Replacing the supporting substrate from fiberglass PCB with a polymer thin film also reduced power consumption by 34%.