Flexible TPU Strain Sensors with Tunable Sensitivity and Stretchability via Coupling AgNWs with rGO
Wearable strain sensors are compelling for health monitoring, while it remains challenging to facilely design flexible strain sensors with both super-high sensitivity and wide sensing strain range in an environment-friendly and scalable way. Besides, the underlying mechanism is still insufficiently studied. Here, we propose a handy method to fabricate flexible strain sensors based on electrospun thermoplastic polyurethane (TPU) mat via coupling silver nanowires (AgNWs) and reduced graphene oxide (rGO). The TPU based strain sensors with AgNWs and rGO have high strain sensitivity and broad working range, respectively, which is due to the morphology difference of these two types of nanomaterials. In contrast, the rGO/AgNWs/TPU sensor shows a synergistic effect on strain sensitivity and sensing range thanks to the interaction between AgNWs and rGO, as well as their coupling effect from assembly. For instance, the sensors with hybrid nanomaterials have an ultrahigh sensitivity (gauge factor, GF≈4.4x107) and a wider detection range by comparison with the counterparts of AgNWs/TPU and rGO/TPU strain sensors (both GFs in the range of hundreds). Besides, the sensors show reliable response to various frequencies and strains, as well as long-term stretching (1000 cycles). Such strain sensors are applicable to monitor human body motions, such as joint motion and muscle movement, enabling potential application in healthcare and human-machine interfacing.
- This article is part of the themed collection: Journal of Materials Chemistry C HOT Papers