Haoyu Wang1,Yunlong Zi1,2
Chinese University of Hong Kong1,The Hong Kong University of Science and Technology (Guangzhou)2
Haoyu Wang1,Yunlong Zi1,2
Chinese University of Hong Kong1,The Hong Kong University of Science and Technology (Guangzhou)2
With the rapid growth of the smart city, wireless sensors are highly preferred in plenty of application scenarios. However, traditional wireless sensing and transmission technology still requires multiple modules for sensing, signal modulation, transmission, and power, making the whole system bulky, rigid, and costly. The posed challenges, including but not limited to the distributed power supply and wireless signal transmission, limit the application scenarios of traditional sensing nodes. To address the challenges of real-time sensing, power supply, and wireless signal transmission in current wireless sensors, we proposed a paradigm shift wireless sensing solution based on the breakdown discharge–induced displacement current. With the working principle of triboelectrification, electrostatic induction, and breakdown discharge, the input mechanical trigger can directly convert to electromagnetic (EM) wave to achieve wireless signal transmission in this solution. Through that, we can combine the abovementioned functional modules in a single unit of self-powered wireless sensing e-sticker (SWISE), which is small (down to 9 mm × 9 mm), thin (down to 95 μm), light (down to 16 mg), intrinsically flexible, and fully self-powered without using batteries or cables, whose signal can be detected over 30 m away omnidirectionally. Furthermore, SWISEs have functions of multipoint motion sensing and gas detection in fully self-powered manner. On the basis of SWISE, through studies about EM wave characteristics and the equivalent circuit model, we put forward the signal modulation strategy of the SWISE wireless signal achieved through the parameters in the equivalent circuit model, such as resistance, capacitance, and inductance, where the experimental result matched the theory. Based on this signal modulation strategy, we couple commercial sensors of different mechanics with the EM wave generated by the triboelectric-discharge effect to realize a general self-powered wireless sensing solution for various physical signals, where the information of the sensors is coupled into the EM wave by SWISE and can be decoded by the receiver. Then, a self-powered wireless temperature and pressure sensing system is demonstrated, with an error rate down to 0.18%, and a multi-point sensing array is also realized for broad potential applications. To conclude, the triboelectric-discharge effect-enabled self-powered wireless sensing system proposes a self-powered wireless information transmission platform that is compatible with various commercial sensors with different physical signals detection abilities, which promises great potential for self-powered wireless sensing in the smart city and Internet of Things, such as robotic dynamic sensing, infrastructure monitoring, human-machine interface, etc.