Design Of Tribo-Piezoelectric Hybrid Nanogenerator Based On Bionic Structure

With the rapid improvement of socio-economic level,the consumption and dependence on energy have further increased.The depletion of traditional fossil fuels such as coal,oil,and natural gas and environmental issues are becoming increasingly prominent,and the development and optimization of new renewable energy sources is urgent.Solar energy,geothermal energy,wind energy,tidal energy,wave energy,bioenergy and other clean energy are increasingly concerned by society,and these types of energy have been used by human beings.However,due to limitations in development technology,economic costs,and effects,their utilization and proportion in human society’s energy have long been low.Developing and optimizing methods for collecting and converting these energy sources is particularly important.Due to the influence of solar radiation,lunar gravity,monsoons,and ocean currents,the water in the ocean is constantly in motion,which makes seawater contain a huge amount of mechanical energy.If it can be collected and utilized,it will bring huge economic benefits to human society.Piezoelectric effect and the emerging technology of triboelectric nanogenerator provide a good solution to the above problems.Based on the principle of triboelectrification and electrostatic induction,triboelectric nanogenerator converts mechanical energy into electrical signal output to realize the collection of randomly scattered mechanical energy in the environment.However,its inherent defects of high internal resistance and low current limit its application in mechanical energy collection.In order to solve this problem,in the second chapter of this paper,its surface was modified to improve its output performance.The most classic way to apply the piezoelectric effect to energy collection is through a cantilever beam structure piezoelectric energy collector,which utilizes the vibration of the cantilever beam to achieve electromechanical conversion of piezoelectric materials,thereby achieving the collection of mechanical energy in the environment.But its eigenfrequency is generally high,and its output efficiency is low under most conditions.In the third and fourth chapters of this article,the experimental analysis of the coupling structure with triboelectric nanogenerator is conducted to reduce the eigenfrequency and improve output performance.The details are as follows:(1)By mechanical imprinting,the fiber structure of mesh materials such as nylon mesh is imprinted onto Al foil.Then,using Al with indentation as the template,polydimethylsiloxane(PDMS)liquid was scraped onto the Al template,cured,demolded,and PDMS thin films with micro-nano structures were obtained.SEM and CLSM were used as characterization methods for the surface morphology of PDMS thin films and Al templates.The PDMS film with micro nano structure is used as the negative friction material of triboelectric nanogenerator(TENG),and the other friction material is smooth Al foil.The electrical output is characterized by the open circuit voltage,short circuit current,and charge transfer of TENG.The experimental results show that TENG made from PDMS thin films with micro-nano structures has higher electrical output performance than smooth PDMS thin films,that is,the output is increased to twice the original.The modified TENG can meet the power supply needs of microelectronic devices such as watches and calculators.by Φ The 3mm 304 SS provides cathodic protection,which can reduce its open circuit potential by 275 m V.(2)Inspired by the flapping characteristics of birds’ wings during flight,a flapping wing friction piezoelectric hybrid generator was constructed.The piezoelectric energy collector of a cantilever beam using polyvinylidene fluoride(PVDF)as the piezoelectric material is the main body of the flapping wing structure.A cube device is added at the end of the cantilever beam as a concentrated mass to improve the motion of the cantilever beam and reduce the eigenfrequency of the low cantilever beam.The so-called cube device refers to the installation of PVDF piezoelectric thin films around the modified TENG mentioned in the previous paragraph.When the two electrode plates of TENG contact and separate to output electrical signals,it can drive the four PVDF piezoelectric thin films around to generate deformation and output electrical signals.The experiment also explored the influence of geometric parameters of the structure on the eigenfrequency,ultimately reducing the eigenfrequency of the entire structure to around 2.5 Hz,significantly reducing the eigenfrequency compared to individual cantilever beam structures and cube devices.(3)Based on the motion characteristics of fish body when swimming,a triboelectric-piezoelectric hybrid generator is constructed.The piezoelectric energy collector with a cantilever beam structure serves as the fish spine,and the TENG electrode plate strung on the beam serves as the fish bone.When the bending deformation of the beam causes the PVDF to produce tensile deformation and output electrical signals,at the same time,the fishbone electrode plate connected to the beam also produces contact separation,and the electrical signals are output due to triboelectrification and electrostatic induction.The electrical output response of the fish spine structure under stable sinusoidal and pulse excitation was experimentally tested.The characteristics and causes of the electrical output of the structure were discussed in detail,and the waveform characteristics of short-circuit current and charge transfer were analyzed in detail.