Study On Textile Triboelectric Nanogenerators Harvesting Multiple "High-entropy" Kinetic Energies

Most renewable energies,including “low grade” renewable waste heat and various types of environmental kinetic energies,are typically irregular and random;most of these energies are wasted due to the difficulties in scavenging them.Considering their wide and irregular distribution,these energies can be termed as “high-entropy” energies,in comparison to traditional electric power with regular managements transmitted from power plants to utility at fixed sites.Meanwhile,the importance of these distributed energies is increasing because that smart terminals for internet of things,in gigantic quantities and wide distributions,are almost impossibly all powered by power cables or portable batteries.Nevertheless,it is getting clearer that no such “high-entropy” energy alone can solve all the energy challenges.Therefore,self-powered electronics or smart terminals integrated with multiple energy harvesters become the promising alternatives.We present a flexible waterproof dual-mode textile triboelectric nanogenerator(TENG),which can scavenge multiple “high-entropy” kinetic energies,including human motions,raindrops and winds.The dual-mode TENG consists of a freestanding-mode TENG(F-TENG)with interdigitated electrodes for collecting the kinetic energy of raindrops;and a contact-separation-mode TENG(CS-TENG)for harvesting mechanical energy from rain drops,winds and human motions.The working principle comes from the combination of contact triboelectrification and electrostatic induction during contact-separation.The main research content for this thesis are as follows:First,a flexible waterproof dual-mode textile TENG has been developed for simultaneously harvesting all the energy sources which exist in raindrop.And the structure parameters of F-TENG are optimized,including the width,the number of electrodes,and different water quality.Considering that the output of each TENG cannot be synchronized,the electrical output can be measured after the rectification circuit.Second,the CS-TENG has been constructed that can adapt to the changing wind direction and wind speed.The wind blowing in the perpendicular direction generates the highest electricity output.Nevertheless,it is also confirmed that wind energy from arbitrary directions can be harvested by the CS-TENG.And last,the CS-TENG has been constructed for collecting mechanical energy from human motions.And its performance is improved by optimizing tiny air gaps between the CS-TENG.the output performance of CS-TENG is measured under various relative humidity conditions,which indicate that this waterproof TENG can resist the failure caused by the rainy weather.Therefore,we demonstrated a facile preparation of TENG-based energy textile that can harvest multiple kinetics energies.And it can be flexibly integrated it in a smart cloth,a tent or some other outdoor facilities.This work will not only take a promising step toward gathering distributed energy,but also open up new prospects for wearable technology.