Crack regulating by multi-level sensory structure towards personalized heath monitoring, human motion tracking, and robotic arm control

Flexible strain sensors have received great interest in health monitoring devices, human–machine interaction, and wearable smart electronics. Expanding the sensing range while maintaining high sensitivity is still a major challenge in sensor system development. Moreover, devising the morphological structure of sensing component is vital for extending their application. Herein, an effective strategy is proposed to construct a multi-level structure of polypyrrole surface-decorated on layered reduced graphene oxide film. Attributed to hindered slippage of graphene due to strong interfacial bonding with polypyrrole, and reduced stiffness mismatch between polypyrrole-graphene and flexible polymer substrate under deformation, the multi-level structure exhibits fascinating comprehensive performance with good mechanical flexibility, improved sensing range (51 %), high sensitivity (GF = 2631), fast response speed (83 ms), and outstanding durability (12500 cycles). Practically, the assembled film sensor demonstrates the characteristics of real-time detection and accurate recognition in acoustic vibration and human physiological activities. Additionally, an integrated communication system is successfully designed for Morse code and sign language communication, as well as robotic arm control to manipulate targeted objects.