Development of Triboelectric Devices for Self-powered Sensing And Energy Harvesting Applications

Abstract

Due to the bulky size and limited lifespan of batteries, remote charging and energy har- vesting from the environment are becoming two trends to power miniaturized electronics. Tri- boelectric nanogenerator (TENG) is an emerging technology to convert mechanical energy to electricitical energy by the coupling of triboelectrification and electrostatic induction. It has been widely applied to self-powered sensing and energy generation by virtue of the simpler device configuration and broader material choices compared to conventional energy conversion technologies, such as electromagnetic and piezoelectric energy harvesters. In this thesis, it is the first time to presented a self-powered on-line ion concentration monitoring system based on the impedance matching effect of TENG. Other than handcrafted TENGs, the rotary disc-shaped TENG (RD-TENG) was fabricated by the industrial printed circuit board (PCB) technology, which could realize sophisticated design and low-cost fabrica- tion. Flowing water, as the energy source, in the pipeline was utilized to drive the RD-TENG and generate an open-circuit voltage (VOC) of ∼210 VP−P. The impedance matching effect of TENG as the sensing mechanism was studied thoroughly. Based on the impedance matching effect, an alarm circuit was designed for the demonstration and the alarm LED can be success- fully lit up by the change of NaCl concentration with only 1×10−5 mol/L, which showed a high sensitivity. Compared to environmental monitoring, healthcare monitoring requires further miniatur- ized size and better compatibility with electronics. To satisfy the demands, a novel micro tri- boelectric energy harvester (μTEH) was developed. Based on the μTEH, a propotyped acoustic energy transfer system was built via an ultrasound link. For the very first time, TENG was fab- ricated by Micro-electro-mechanical systems (MEMS) technologies in batch process, giving better integrated circuit (IC) integration. More importantly, it is also the first time that the size of TENG is brought into microscale. We demonstrated a prototyped acoustic energy transfer system for implanted devices that could generate 50 nW power on load resistor under 1 MHz, 132 mW/cm2 incident acoustic power. The μTEH also achieved a signal-to-ratio (SNR) of 20.54 dB and exhibited promising potential for wireless communication by modulating the in- cident ultrasound. Finally, detailed optimization methods were proposed to improve the output power of the μTEHs in the future.