Ultra-dense and ultra-low power microhotplates using silica aerogel

A thin film of silica aerogel has been spin coated on silicon wafers to investigate its super thermal insulating capability. The temperature of the thin film heaters fabricated on the aerogel coated wafer is measured at different applied powers. Simulations are performed to compare the aerogel coated wafers with the micromachined wafers. Both experimental and simulation results show better heat insulation for aerogel coated wafers as compared with simulated micromachined wafers. The measurement and simulation results of aerogel coated wafers are in good agreement. The aerogel film can replace the air cavity created by conventional micromachining of wafers to save power and chip area in metal oxide gas sensor arrays.