Smart algorithm enabled and cell phone operated multi-chip portable gas sensor

In recent years, air pollution has become a serious issue. Ozone (O3) and nitrogen dioxide (NO2) are indicative harmful gases due to their threats to human health even at concentrations of just a few tens of parts per billion (ppb). This technique develops a low-cost chemical process for producing nanocomposite based gas sensing chips. A cell phone operated portable gas sensor with smart algorithm has also been constructed. By measuring the sensor chip resistance, environmental temperature, and humidity, the algorithm gives individual O¬3 and NO2 concentrations. A lowest detection limit of 1 ppb can be achieved, meeting environmental monitoring requirements set by the Ministry of Environment. In addition, batch production of 300 sensor chips on a four-inch Si wafer is realized. The portable sensor is ready for commercialization in one to two years and targeted for the IoT sensor market in ppb-level environmental monitoring of toxic gases.

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