Congratulations to Dr. Ren Jing for receiving the paper by InfoMat

The strain sensor can transform the mechanical deformation into a detectable electrical signal, and has a good application prospect in the fields of intelligent robot, medical monitoring, human-computer interaction interface and bionic prosthesis. Among them, the real-time monitoring of human exercise behavior can effectively assess its health status, which is of great significance in wearable medical diagnosis and personal health monitoring. For human motion monitoring, the ideal strain sensor component needs to have both high elongation and good stability, thus providing the possibility to achieve full-scale human motion detection. In addition, due to the diversity and complexity of human motion, the stability of strain sensors under different application conditions (temperature, frequency, etc.) is equally important. However, the flexible strain sensors reported so far are often unable to have the above properties at the same time, which limits their application range.

Recently, Dr. Ren Jing developed a flexible tensile strain sensor based on the structure of graphene “sliding varistor”. The resistance is changed by changing the contact area between adjacent graphene sheets. The sensor has high tensile rate (70%), excellent cycle stability (300,000 times), and stable response in the frequency range of 0.1-5 Hz and temperature range of -45 °C - 180 °C, achieving full-scale human motion monitor. It was found by in-situ transmission electron microscopy that the graphene sheets which overlap each other produced a slip under the action of an external force, and the contact area thereof also changed, thereby generating a resistance change. The deformation of the macroscopic structure by the three-dimensional network controls the slip of the graphene sheet within a reversible range, which greatly improves the cycle stability of the strain sensor and the stability over a wide temperature and frequency range. The excellent sensing performance makes the strain sensor suitable for the monitoring of large-scale movements (walking, squatting) of the human body, as well as small-scale movement and monitoring of weak physiological signals (breathing, pulse). The research results have great application prospects in the fields of personal health monitoring, intelligent robots and wearable electronic devices. The structural design of graphene "sliding rheostat" provides a new idea for new multi-function sensors.

This work was published on InfoMat (DOI: 10.1002/inf2.12030) under the title "A graphene rheostat for highly durable and stretchable strain sensor".

Paper link: https://onlinelibrary.wiley.com/doi/full/10.1002/inf2.12030