My research group published a review: Overview and prospects of research on flexible and transparent

With the rapid development of social economy and the continuous improvement of the level of industrialization and urbanization, the problem of atmospheric pollution has become increasingly severe. The development of real-time, high-efficiency, and wearable gas sensors will help real-time warning of hazardous gases, failure indications of disaster protection equipment on site, and effective treatment of polluting gases. At the same time, the type and content of gases in human exhaled breath are closely related to human health. The development of a thin-film sensor that can potentially be integrated into wearable devices and the application of the marker gas detection in the exhaled breath of the human body is to achieve non-invasive disease. The key to painless, convenient diagnosis. Combining the opportunity of rapid development of current flexible electronic devices, a flexible, transparent gas thin film sensor is integrated in various types of wearable electronic devices, and a smart wearable electronic integrated device that can respond to gas at room temperature, in real time, and with specificity is expected. Therefore, flexible and transparent gas sensors for wearable devices have great research significance and application prospects for the real-time monitoring of environmental pollution gases and the development of medical diagnostics.

At present, the doping of gas molecules in semiconducting nanomaterials is an effective way to build resistive gas sensors; however, in order to achieve fast desorption of gas molecules on the surface of nanoparticles, high temperature or ultraviolet light irradiation above 200°C is often needed technology. Although semiconductor nanomaterial-based gas sensors exhibit excellent sensor response and selectivity, additional assistive technologies such as high temperature or ultraviolet light irradiation have greatly limited the development of flexible, transparent room temperature sensors. Gas sensors based on carbon nanomaterials generally allow room-temperature gas sensing, and sensors can be built on a flexible substrate, but the gas sensing response is low. Conductive polymer-based thin-film sensors exhibit good room-temperature gas sensing performance and high sensor response, but they have defects in film transparency and lack of sensing stability. Therefore, through the controllable assembly technology to build nano-composite materials and to achieve a flexible, transparent film of the uniform deposition preparation, combined with the advantages and synergy effects of the room temperature sensing materials, help to build high-performance flexible, transparent gas sensor.

Recently, Prof. Sun Xiaoming and Prof. Wan Pengbo from Beijing University of Chemical Technology and Prof. Xiaodong Chen from Nanyang Technological University of Singapore and Prof. Zhang Wei from Shenzhen University have cooperated with each other on a series of flexible, transparent and self-healing thin film sensors. Reviewing flexible and transparent gas sensors based on semiconducting nanomaterials, carbon materials, and conductor polymers in recent years, the system summarizes strategies for improving flexibility, transparency, and sensing performance, including the control of the topography of sensing materials, materials, The assembly method, the uniform deposition of the thin film, the selection and optimization of the substrate, etc.; The deficiencies of the existing flexible and transparent sensors, such as the rapid detection of the specificity of organic volatile gases, the sensitivity to environmental changes during practical application, and portable wearability And the signal wireless transmission performance is not good; and look forward to the direction of further development of flexible, transparent sensors for wearable devices, such as the further realization and improvement of simultaneous detection of a variety of gases, sensing of environmental stability, portable wearable devices and more Functional integration, miniaturization of sensors and A sense signal to the wireless transmission Ipad, mobile phones, Watch the like integration equipment and the like. This will provide new research ideas and theoretical basis for the future development of flexible, transparent and wearable gas sensors. Related results were published online in Small (DOI: 10.1002/smll.201601049).