Ultrathin encapsulated rGO strain sensor for gesture recognition

As an important component of wearable devices, strain sensors have attracted extensive attention. Usually, the exposed strain sensors have better gauge factor (GF) but a small strain range. Encapsulation can increase the strain range, but the influence of the encapsulation on device performance remains elusive. In this work, we proposed a reduced graphene oxide (rGO) strain sensor based on ultrathin polyurethane (PU) encapsulation layer. The maximum strain range of single-layer encapsulated PU-based rGO strain sensor (PGSS) can reach 51%, and its GF is between 8.02 and 125.05. In addition, we explored the effect of thickness of encapsulated layer on the performance of PGSS. For the strain-resistance change rate curve, within the same strain range, the PGSS with thinner encapsulation layer is more sensitive to force. Furthermore, a smart glove based on PGSS was developed, which can effectively distinguish ten different gestures. This work has high potential in the fields of physiological signal monitoring and human-machine interaction.