Progress in Flexible Humidity Sensor and Non-contact Control for Semiconductors

Human-computer interaction technology has attracted extensive attention due to its important application in the Internet of Things (IoT), such as wearable electronics and remote medical monitoring.  For human-computer interaction systems, intelligent sensors play a key role because they can effectively "convert" various signals from the human body into information that the machine can recognize.  Therefore, it is particularly important to develop various intelligent sensors with high sensitivity and fast response.  Conventional sensors usually detect signals in direct contact, such as pressure sensors, strain sensors, etc.  However, direct contact sensing will not only bring about inevitable mechanical wear, but also limit its application in a wider range such as toxic or harmful environment.  In order to overcome these shortcomings and meet various application requirements, flexible non-contact humidity sensors become an important supplement to existing sensors and can be used as a new control method for advanced human-computer interaction systems.

Recently, the research group of Shen Guozhen, a researcher at the State Key Laboratory of Superlattices, Institute of Semiconductors, Chinese Academy of Sciences, has successfully developed a flexible and transparent high-performance humidity sensor, which is based on MoO3 nanosheets and is synthesized by a low-cost, simple solution method.  The humidity sensor has excellent sensitivity to external relative humidity (RH), and the current changes by 5 orders of magnitude when RH changes from 0% to 100%.  In addition, the sensor has fast response (< 0.3 s) and recovery time (< 0.5 s), also shows long-term stability (> 1 month), and has good mechanical flexibility.  Meanwhile, researchers have developed a wearable humidity analysis system for environmental RH monitoring and non-invasive human respiratory monitoring.  In addition, the remote non-contact interactive sensing characteristic of the humidity sensor is applied to two personal computer interaction systems of a non-contact multi-stage switch and a flexible non-contact control screen.


This work provides a great application prospect and feasible process for humidity sensor based on oxide nanomaterials in intelligent human-computer interaction system.  This work is supported by the National Natural Science Foundation and the leading scientific research projects of the Chinese Academy of Sciences.  The research results were published in the journal Small (DOI: 10.1002/SMLL.201902801).