Pan Wei, Xia Wei, Jiang Feng-Shuo, Wang Xiao-Xiong, Zhang Zhi-Guang, Li Xia-Gui, Li Peng, Jiang Yong-Chao, Long Yun-Ze, Yu Gui-Feng
College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109, China.
Collaborative Innovation Center for Nanomaterials & Devices, College of Physics, Qingdao University, Qingdao 266071, China.
Nanomaterials (Basel). 2020 Oct 7;10(10):1980. doi: 10.3390/nano10101980.
Wearable electronics, such as sensors, actuators, and supercapacitors, have attracted broad interest owing to their promising applications. Nevertheless, practical problems involving their sensitivity and stretchability remain as challenges. In this work, efforts were devoted to fabricating a highly stretchable and sensitive strain sensor based on dip-coating of graphene onto an electrospun thermoplastic polyurethane (TPU) nanofibrous membrane, followed by spinning of the TPU/graphene nanomembrane into an intertwined-coil configuration. Owing to the intertwined-coil configuration and the synergy of the two structures (nanoscale fiber gap and microscale twisting of the fiber gap), the conductive strain sensor showed a stretchability of 1100%. The self-inter-locking of the sensor prevents the coils from uncoiling. Thanks to the intertwined-coil configuration, most of the fibers were wrapped into the coils in the configuration, thus avoiding the falling off of graphene. This special configuration also endowed our strain sensor with an ability of recovery under a strain of 400%, which is higher than the stretching limit of knees and elbows in human motion. The strain sensor detected not only subtle movements (such as perceiving a pulse and identifying spoken words), but also large movements (such as recognizing the motion of fingers, wrists, knees, etc.), showing promising application potential to perform as flexible strain sensors.
可穿戴电子产品，如传感器、致动器和超级电容器，因其广阔的应用前景而备受关注。然而，涉及其灵敏度和可拉伸性的实际问题仍然是挑战。在这项工作中，致力于通过将石墨烯浸涂到电纺热塑性聚氨酯（TPU）纳米纤维膜上，然后将TPU/石墨烯纳米膜纺成交织线圈结构来制造一种高度可拉伸且灵敏的应变传感器。由于交织线圈结构以及两种结构（纳米级纤维间隙和纤维间隙的微米级扭曲）的协同作用，该导电应变传感器的可拉伸性达到了1100%。传感器的自互锁防止了线圈解开。得益于交织线圈结构，大多数纤维在该结构中被包裹在线圈中，从而避免了石墨烯脱落。这种特殊结构还赋予我们的应变传感器在400%应变下的恢复能力，这高于人体运动中膝盖和肘部的拉伸极限。该应变传感器不仅能检测细微动作（如感知脉搏和识别语音），还能检测大幅度动作（如识别手指、手腕、膝盖等的运动），显示出作为柔性应变传感器的广阔应用潜力。
