Flexible Timbo‐Like Triboelectric Nanogenerator as Self‐Powered Force and Bend Sensor for Wireless and Distributed Landslide Monitoring

DOI: 10.1002/admt.201800144 large numbers of casualties, huge economic losses, and severe damages to structures and infrastructures.[1,2] In general, the landslide is a form of mass wasting that includes a wide range of ground movements, such as rockfalls, deep-seated slope failures, and superficial landslides, which needs to be monitored at all times. Conventional methods, including geomorphological field mapping,[3] visual interpretation of stereoscopic aerial photographs,[4] triangulation,[5] and electronic distance measurement (EDM)[6] have been investigated for mapping landslides and monitoring slope instabilities. Unfortunately, these methods are time-consuming and resource-intensive.[7,8] At present, multiple approaches based on satellite, airborne, and terrestrial remote sensing technologies have been researched extensively, promising to reduce the time and resources required for compilation and systematic update.[7,9] Nevertheless, underlying problems such as vegetation overgrowth and night-capturing restrictions make it difficult to monitor from optical images and cause false alarm incidents, thus limiting their utilization.[10] Furthermore, subsurface landslides are difficult to identify using standard aerial photography or satellite imaging.[7,10,11] To monitor subsurface landslides, other technologies, such as electrical resistivity tomography As worldwide landslides frequently result in enormous casualties and huge economic losses, new landslide monitoring technologies are urgently required to develop for preventing and mitigating landslide hazard. In this paper, a selfpowered, flexible, timbo-like triboelectric force and bend sensor (TTEFBS) is proposed and implemented, with the aim of effectively monitoring landslides. The fabricated TTEFBS, based on a single-electrode working mode, consists of a timbo-like inner polydimethylsiloxane (PDMS) core coated with a carbon electrode and an outer silicon rubber tube. Owing to the novel structure and sensing mechanism, the TTEFBS achieves high sensitivities (5.20 V N−1 under pressing and 1.61 V rad−1 under bending), fast response/relaxation time (<6 ms), and long-term stability/reliability (more than 40 000 cycles). Furthermore, a wireless and distributed monitoring system using an array of TTEFBSs is developed for systematically detecting rockfalls, deep-seated landslides, and superficial landslides. Additionally, a zigzag-structured triboelectric nanogenerator (Z-TENG), characterized by an open-circuit voltage of ≈2058 V and a short-circuit current of ≈154 μA, is successfully fabricated for scavenging energy from moving cars to provide power in wild environments, thereby forming a self-powered monitoring system. This work may further inspire rapid progress of TENG in applications of wireless, distributed sensing, and environmental/infrastructure monitoring.