۱- Introduction

۲- Methods to achieve frequency boost up by instantaneous discharging

۳- The basic characterization of TENG-based direct wireless transmission

۴- The static force sensing based on resonant frequency shift

۵- Wireless toy car control

۶- Wireless 3D VR drone control

۷- Conclusion

۸- Experimental section

References

Abstract

Wireless Sensor Networks (WSNs) bring the basis that the development of the Internet of Things (IoTs) relies on. However, external power requirement restricts the widespread applications of WSNs. Triboelectric nanogenerator (TENG) has been a promising candidate for energy harvesting and self-powered sensing, but most of the reported TENG-based WSNs need to store energy in a capacitor first and then power the wireless modules without a continuous sensing capability simultaneously. In this work, a battery-free short-range self-powered wireless sensor network (SS-WSN) is proposed by using TENG-based direct sensory transmission (TDST). By leveraging a mechanical switch or diode-switch combination, enhanced output and boosted frequency of TENG signal have been achieved by instantaneous discharging in a short period, initiating the potential for direct signal transmission without additional wireless modules and external power suppliers. Different from others’ works, the stable resonant frequency is used to realize the force-sensing function with high sensitivity (434.7 Hz.N−۱), in which case a wireless real-time electronic scale is demonstrated. Additionally, by varying the connections of the textile TENGs or the capacitance of an external capacitor for distinguishable resonant frequencies generation, the multiple-freedom-degree 2D toy car control, and 3D VR drone control are demonstrated with a single coil.

Introduction

Nowadays, Wireless Sensor Networks (WSNs) have attracted lots of attention from researchers in a wide variety of areas due to their ubiquitous nature and their tremendous development in the Internet of Things (IoT) [1–۵]. IoT, which enables the wireless connection and controlling of devices through the internet, has been used in diversified applications for remote monitoring and sensing, such as environmental monitoring [6,7], smart home [8,9], and healthcare [10–۱۴]. With the rapid development of IoTs, wearable electronics, which shape the human lifestyle, are in a great demand for the applications of human-machine interfaces (HMIs) [15–۲۲], control [23,24], communication [25] and wireless networks [1,26–۲۹]. Due to its unique characteristics, such as light-weight, soft, permeable and conformable, the cost-effective textile has become a promising candidate for wearable sensors in IoT networks [30–۳۳]. However, the large power consumption for long-term connectivity, especially with the increasing number of sensors becomes the major bottleneck of WSN technologies [34]. To overcome this issue, different kinds of energy harvesting techniques, which scavenge various forms of energy from the ambient environment, are explored extensively in recent years, including the solar energy [35], kinetic energy [36], thermal energy [37], and the radio frequency (RF) energy [38]. Nevertheless, most of the reported energy harvesting techniques for wireless sensing could only fulfil the function of battery life extension rather than eliminating the usage of power supply, where the scavenged energy is stored into a capacitor or battery for later use.