Smartphones turned into air quality monitors - portable gas sensor for accurate detectionMay 23, 2024

Air pollution is a critical global issue, and in recent years, the dangers of gases such as ozone and nitrogen dioxide have gained increased attention. Most existing air quality monitors can only detect a single type of gas and are susceptible to environmental factors like high temperature and humidity.

Professor Heh-Nan Lin's team at National Tsing Hua University has developed a smartphone-controlled, multi-chip portable gas sensor with intelligent algorithms. This sensor overcomes the limitations of current small gas sensors by simultaneously detecting ozone and nitrogen dioxide without being affected by high temperature and humidity, significantly improving the sensitivity and accuracy of air pollution monitoring.

Breakthrough technology overcomes limitations of existing small gas sensors

This innovative sensor utilizes semiconductor oxide nanocomposite materials to detect ozone and nitrogen dioxide concentrations with a minimum detection limit of 1 ppb. Comparative tests with standard analytical instruments show an accuracy of over 90%. Compared to commercial sensors, it boasts higher sensitivity at less than a quarter of the cost. Additionally, its compact size makes it portable and suitable for extensive deployment, unaffected by temperature and humidity, ideal for both indoor and outdoor applications.

Intelligent algorithms for precise gas concentration detection

The sensor connects to a smartphone via Bluetooth, which reads resistance, temperature, and humidity values from the sensor. It employs an artificial neural network algorithm to calculate current gas concentrations, and the data can be uploaded to the cloud. The algorithm, trained on vast datasets, effectively eliminates interference from other gases, allowing precise detection of ozone and nitrogen dioxide levels.

Feasible mass production with high market competitiveness

Professor Heh-Nan Lin highlighted that the sensor's production process is simple and environmentally friendly, using common commercial materials. The team can already achieve small-scale production, producing one four-inch silicon wafer every four hours, yielding approximately 300 gas sensor chips per wafer. The sensor can be widely applied in large public spaces, homes, factories, clean rooms, general outdoor air quality monitoring, biomedical environments, and more. Its excellent performance and cost advantage meet the market's demand for semiconductor-based sensors, indicating strong commercial potential.

Resource (Mandarin)