Rational design of fast recoverable shape-memory photoelectric spring in response to tiny deformation for monitoring underwater microvibration

摘要

Underwater vibration detectors have aroused intensive attention due to the promising applications in personal security, environmental protection and military defense. However, how to enable an underwater detector with combined feature of excellent structural flexibility and robustness as well as high detection sensitivity and stability, still remains a significant challenge. Herein, we successfully designed and developed a pitch-modulated spring with photoelectric response to its tiny deformation, via intercalating hydrogenated TiO2 (H-TiO2) nanoparticles between mutual contacting graphene sheets as the skeleton. Thanks to the intercalated spring architecture, the as-fabricated H-TiO2/graphene spring achieved good visible light absorption, fast shape recovery (1 s), excellent shape-memory repeatability (1000 cycles) at 30% stretching, as well as high structural and electrical stability even in saline solution over 10 days. Importantly, resulted from the variation of effective illumination area under stretching and compressing, the spring featured a significant fluctuation of photocurrent. Thus, the spring detector delivered high sensitivity and stability in monitoring underwater microvibration induced by bubble rising, and the underwater microvibration amplitude could be detected by the output photocurrent signal. This work has shed light on new strategies for designing and fabricating robust underwater microvibration detectors with high sensing performance toward future uses.