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.

水下振动探测器由于在人身安全，环境保护和军事防御方面的前景广阔的应用而引起了广泛的关注。然而，如何实现具有优良的结构柔性和鲁棒性以及高的检测灵敏度和稳定性的组合特征的水下探测器仍然是一个重大挑战。在这里，我们通过将氢化的TiO ₂（H–TiO ₂）纳米粒子插在相互接触的石墨烯片之间作为骨架，成功设计并开发了对微小变形具有光电响应的变调弹簧。得益于插层式弹簧结构，制成的H–TiO ₂/石墨烯弹簧在30％拉伸时获得了良好的可见光吸收，快速的形状恢复（<1 s），出色的形状记忆可重复性（> 1000个循环），以及即使在盐溶液中10天也具有很高的结构和电稳定性。重要的是，由于拉伸和压缩下有效照明面积的变化，弹簧的光电流出现了明显的波动。因此，该弹簧检测器在监测由气泡上升引起的水下微振动方面具有高灵敏度和稳定性，并且可以通过输出光电流信号来检测水下微振动幅度。这项工作为设计和制造对未来用途具有高传感性能的坚固的水下微振动探测器提供了新的策略。