Device On Water Energy Harvesting And Vibration Sensing Based On Triboelectric Effect

The triboelectric effect is one of the most universal phenomena in our daily life,which has drawn much attention due to the invention of triboelectric nanogenerator by Prof.Zhonglin Wang's group in Georgia Institute of Technology.In this dissertation,the research efforts have led to the development of several types of devices including transparent TENG,transparent multi-unit TENG and flexible and tubular multi-unit TENG to harvest water-related energy.In addition,the performances of triboelectric nanogenerator as self-powered vibration sensor are systematically investigated,from individual vibration sensor to vibration sensor array.Last but not least,by integration with transient electronics,a fast soluble and recyclable green triboelectric nanogenerator is demonstrated.The details of this dissertation are described as below:A glass-based highly transparent triboelectric nanogenerator(T-TENG)operated under single-electrode mode was developed to harvest the electrostatic energy from flowing water.With the PTFE film acting as an antireflection coating,the maximum transmittance of the fabiricated T-TENG is 87.4%,which is larger than that of individual glass substrate.The instantaneous output power density of the T-TENG is 11.56 mW/m2 when connected to a load resistor of 0.5 M?.An integrated multi-unit transparent triboelectric nanogenerator(MT-TENG)was developed for green energy harvesting.The instantaneous output power density reaches 27.86 mW/m2,which is 11.6 times of that generated from individual T-TENG with the same working dimension.The improvement of efficiency of the MT-TENG resulted from the facilitation of charges transfer.Besides,the rational design of the MT-TENG is capable of overcoming the degradation and complete failure problem facing the water-based T-TENG.The dependence of temperature and pH value of water on the electric outputs is also systematically studied in consideration of different application environment.A flexible and tubular multi-unit triboelectric generator(TEEG)for harvesting water related energy in our living environment was developed.With the flowing rate of the tap water of 35 ml/s,the instantaneous output power density of the multi-unit TEG array is 0.07 W/m2.The influences of flow and falling height of water and the tilt angle of TEG were systematically studied.The regulation methods of the output of TEG were explored.By integrating with the multi-unit TEG,the household faucet can be a power source to supply clean energy continuously.A dual mode self-powered vibration sensor based on a triboelectric generator(TEG)using triboelectrification and electrostatic induction effects was demonstrated.The vibration sensor could realize detection under contact mode and non-contact mode,which would protect the device and the detected objects in operation from mechanical and chemical damage.The vibration sensor delivers a detection range of 0-500 Hz,high accuracy(relative error below 0.42%),long-term stability(10000 cycles).Then we stepped further by designing and fabricating an active sensor system for vibration monitoring with multiplexed operation.The as-fabricated sensor matrix is capable of monitoring and mapping the vibration state of large amounts of units.The monitoring contents include:on-off state,vibration frequency and vibration amplitude of each unit.On the time dimension,the sensor can provide the vibration process memory by recording the outputs of the sensor system in an extend period of time.A fast soluble,recyclable and green triboelectric nanogenerator was successfully developed.All the components are water-soluble or can be dissolved by water-triggered cascade reaction.The entire device get fully disintegrated and dissolved with a transience time within minutes once the external trigger of water commences.Moreover,it can be reproduced with the generated solution with no waste released to environment.The developed recyclable triboelectric nanogenerator exhibited excellent performance of scavenging mechanical energy from environment.We also demonstrated its potential applications on clearable self-powered nanosensors for health monitoring and motion sensing.The recyclable and green triboelectric nanogenerator renders as a promising power solution for biomedical implants,environmental monitoring and secure electronics.