Contact-Resistance-Free Stretchable Strain Sensors with High Repeatability and Linearity

作者：Shuang Li, Ye Liu, Rui Li, Qinlan Li, Yang Zhao, Mingqi Huang, Maoyi Zhang, Shizhen Yin, Yixin Zhou, Hao Tang, Liwu Wang, Guanhui Fang, Yewang Su · 发表于：ACS Nano · 年份：2021 · DOI：10.1021/acsnano.1c07645 · 被引用次数：132 · 研究领域：Advanced Sensor and Energy Harvesting Materials、Tactile and Sensory Interactions、Muscle activation and electromyography studies

Most of the existing stretchable strain sensors are based on the contact-resistance mechanism, where the stretchability and resistance variation depend on the change of the contact relationship of the conductive microstructures. These sensors usually exhibit large sensing ranges and gauge factors but unsatisfactory repeatability and linearity of the electrical responses because the contact is unstable. Here, we report a completely different design for stretchable strain sensors based on a contact-resistance-free structure, i.e., the off-axis serpentine sandwich structure (OASSS), with the mechanism of the stretch-bending-stretch transformation (SBST). Neither unstable contact resistance nor nonlinear constitutive and geometric behaviors occur for the OASSS while the sensor undergoes a large applied strain (50%), which guarantees high repeatability (repeatability error = 1.58%) and linearity (goodness-of-fit >0.999). Owing to such performances, the present sensors are not only applied to monitoring human activities and medical surgery but also to the ground tests of Tianwen-1, China's first Mars exploration mission.