Robust and flexible triboelectric nanogenerator using non-Newtonian fluid characteristics towards smart traffic and human-motion detecting system

Due to the self-powered property of the triboelectric nanogenerator (TENG), development of the TENG based sensor is highly required to solve the major obstacles composed of the size and power consumption issues induced by external power source of the conventional Internet of Things (IoT) device. However, the conventional TENG based sensors are generally composed of thin films and these films can be easily damaged by external impact. With these damaged films, a malfunction of the conventional TENG based sensor can occur, which can induce an accident in a place where these sensors are utilized. Herein, the non-Newtonian fluid (NNF) with the shear thickening phenomenon (STP), which can increase its robustness as the applied external force to the NNF increases, is utilized to fabricate the TENG. Hence, the fabricated NNF with the STP based TENG (NNFT) is possessing the high resistance to impact as well as flexibility, simultaneously. The water-assisted oxidation is conducted to form the nanostructures on the surface of the Al electrode at the NNFT. Also, by adding the polyvinylidene fluoride powder into the NNFT (NNFT-P), the high open-circuit voltage of 260 V, short-circuit current of 11.2 μA, and power density of 37.5 mW/m2 are generated from the NNFT-P. As an application, the NNFT-P based self-powered traffic detection system (NSTDS) is implemented. With the NSTDS, the dangerous situation is successfully alerted to the pedestrian without significant damage in the NSTDS when the speeding vehicle is passing the NSTDS. Furthermore, the human motions including walking, running, and jumping are successfully detected with the proposed NNFT-P. Considering these results, the proposed NNFT-P is predicted to be utilized as the smart traffic system as well as human motion detecting sensor in near future.