High-performance metal oxide nanowire chemical sensors with integrated micromachined hotplates

We demonstrate the fast and scalable integration of nanowire chemical sensors with micromachined hotplates built on SiN membranes. These hotplates allowed nanowire chemical sensors to operate at elevated temperatures in order to enhance the sensitivity of chemical sensors to target gases. By applying different currents through the platinum heating filament, we can easily vary the device temperature from room temperature to 350°C. These nanosensors with integrated hot plates have been exploited for the detection of ethanol, CO, and hydrogen down to concentrations of 1, 10, and 50ppm, respectively.