An ultralow power nanosensor array for selective detection of air pollutants

Semiconducting metal oxide gas sensors typically operate at a high temperature and consume hundreds of milliwatts of power. Therefore there is great demand for the development of a low-power gas-sensing technology that can sensitively and selectively detect the gas analytes present in the atmosphere. We report an ultralow-power nanosensor array platform, integrated with an independently controlled nanoheater of size 4 mu m x 100 nm, which consumes similar to 1.8 mW power when operated continuously at 300 degrees C. The heaters exhibit a fast thermal response time of less than 1 mu s, and can be utilized to operate in duty cycle mode, leading to power saving. The active area of the nanosensor is 1 mu m x 200 nm, defined by sensing electrodes with a nanogap of similar to 200nm, leading to small form factor. As a proof of concept, each of the sensing elements in the array is functionalized with different sensing materials to demonstrate a low-power, sensitive and selective multiplexed gas-sensing technology for the simultaneous detection of CO (similar to 93.2% for 3 ppm at 300 degrees C), CO2 (similar to 76.3% for 1000 ppm at 265 degrees C), NO2 (similar to 2301% for 3 ppm at 150 degrees C) and SO2 (similar to 94% for 3 ppm at 265 degrees C). The technology described here uses scalable crossbar architecture for sensor elements, thus enabling the integration of additional sensing materials and making it customizable for specific applications.