Virtual Alternating Current Measurements Advance Semiconductor Gas Sensors’ Performance in the Internet of Things

Semiconductor gas sensors are important candidates with small size, low-power consumption, and low-cost characteristics for gas sensing in the Internet of Things (IoT), but the nonlinear response, unstable baseline, and the variability of the responses toward temperature and humidity fluctuation harm its performance. Here, we proposed a new technique called virtual alternating current (ac) measurements to enable semiconductor gas sensors to achieve high linear response ( $R^{2}>0.99$ ), stable baseline, and easily calibrated temperature and humidity fluctuation. The most outstanding advantage of our technique is to achieve excellent performance simply by measuring resistance. The universality and feasibility of our technique were verified by a range of commercial and homemade sensing elements and a range of analyte. We also successfully generalized our technique to non-Debye relaxation systems, which further expands the scope of semiconductor gas sensor types available in our technique. We believe that our technique will enable gas sensing nodes built with semiconductor gas sensors in the IoT to achieve markedly superior performance.