Highly sensitive gas sensors on low-cost nanostructured polymer substrates

SnO2 thin-film gas sensors have been successfully fabricated on nanospiked polyurethane polymer surfaces, which are replicated by a low-cost soft nanolithography method from silicon nanospike structures formed with femtosecond laser irradiations. Measurements revealed significant response to carbon monoxide (CO) gas at room temperature, which is considerably different from the sensors of SnO2 thin films coated on smooth surfaces that show no response to CO gas at room temperature. The high area/volume ratio and sharp structures of the nanospikes enhance the sensitivity of SnO2 at room temperature. This will greatly decrease the electrical power consumption of the gas sensor and the cost for calibrations, and has great potential for application in other sensing systems.