The Working Principle And Influence Factors Of Triboelectric Nanogenerator Based On PDMS

The ambient environment contains abundant mechanical energy, which is relatively small and irregular. Because of that, conventional generators can not effectively achieve energy conversion. Triboelectrical naogenerator(TENG) which is based on the contact triboelectricification and electrostatic induction provides a promising route for harvesting ambient mechanical energy and converting it into electric energy. In this paper, several polydimethylsiloxane(PDMS) films are prepared by mold method and fabricate a TENG. Inductively coupled plasma(ICP) and particles adding are ultilized to modify the surface and change the peopertity of PDMS films, and the electrical output of PDMS films are systematically studied. The specific work and the results are as follows:Firstly, several PDMS films are prepared through mold method by spin coated. ICP is used to etch the surface of flat PDMS films and PDMS films with micro rod array. Surface morphology, roughness and section thickness were characterized by scanning electron microscopy(SEM) and atomic force microscopy(AFM). The results show that the surface of PDMS films are relatively smooth, the surface average roughness is 0.837 nm, the thickness of PDMS films are 250 μm and the height of PDMS micro rod array is 30 μm.Secondly, the Matlab software is used to simulate and analyse the open-circuit voltage-transfered charge-distance(V-Q-X) relationship, and the electrical output of flat PDMS films shows that the open-circuit voltage(Voc) and short-circuit current(Isc) are 2.8 V and 0.24 μA, respectively. The analysis reveals that electrical output increases quasilinearly with the increase of the external load, and then shows a tendency toward saturation.Thirdly, several influences as the surface structure and external load on the electrical output of the TENG are systematically studied by integrating use of experimenal tests and ANSYS simulation. Results show that the existence of micro rod array on the PDMS films effectively enlarges the contact area and provides more surfaces for charge storage and hence improve the output performance of TENG. When keeping the external load constant, the output increases with decreasing distance between micro rods. When the external load is 5 N and the distance is 15 μm, the average output voltage and current as high as 88 V and 15 μA can be achieved respectively, which is 1.5 times higher than the output generated when the distance is 50 μm. The electrical output increases quasilinearly with the increase of the external load. Simulation results show that the micro rods of PDMS films are mainly compressed by normal load, which results in a larger diameter of micro rods. The deformations of PDMS substrate leads to the lateral friction between the micro rods and the upper electrode, which produces more charges because of the friction.Lastly, the PDMS films are etched by ICP processing, when using argon treatment, the optimized parameters are 60% of the power and 5 min. The electrical output increased by more than 2.6 times compared to none-processed PDMS films. The Voc and Isc of ICP processed micro rod array increase from 42 V and 4.2 μA to 72 V and 8.3 μA, respectively. The output has increased by more than 3.6 times, compared to the flat PDMS films, showing that compound processing has a distinct improvement to the output performance of TENG. However, the output performance decreases by 35% after the processed films were preserved for 3 months. The influence of copper nanoparticles on TENGs reveals that the copper nanoparticles adding can improve output perfomance of TENGs. When the mass fraction of copper nanoparticles is 2.5%, the output is the highest. Voc and Isc are 6.8 V and 0.56 μA, repectively, increasing by 2.33 times comparing with that of pure PDMS films. The electrical output increases quasilinearly with the increasing of external load.