The Research Of Flexible Triboelectric Nanogenerator For Self-powered Human Motion Information Collection

In recent years,many new types of wearable electronics are being widely used in our daily life,and their associated energy supply devices are required to be flexible,bendable,good reliability,adaptable to the body's movement and easy to be integrated.Traditional chemical battery has the fatal defects of non-flexible structure,large size,limited lifetime and environmentally unfriendliness,and is not suitable for the development trend of flexible electronic devices.As a novel energy harvesting method,triboelectric nanogenerator?TENG?have been proposed to convert many kinds of mechanical energy into electricity as the result of the coupling of triboelectrification and electrostatic induction.With the advantages of structural flexibility,environmental friendliness and high efficiency,triboelectric nanogenerator?TENG?have received extensive attention in the field of energy harvesting.The energy from human motion exist everywhere in our daily lives,including walking,running,flapping and so on.If these energy can be converted into electric energy,they can meet the energy consumption requirements of most wearable electronic devices.Therefore,converting low-frequency,different-amplitude human motion energy into electrical energy is an effective and environmentally friendly way to solve the energy supply problem for wearable electronic devices,and to construct self-powered sensors for human motion signal monitoring and health signal monitoring.On the basis of the practical energy supply demand of wearable electronic devices and human motion status monitoring,we analyzed the factors that improve the output performance of the triboelectric nanogenerator.A textile-based flexible triboelectric nanogenerator was fabricated which can efficiently convert the human motion energy into electrical energy and realized the motion statistics.A core–shell coaxially structured triboelectric nanogenerator with high sensitive characteristics was designed for energy harvesting and motion sensing.The whole research can be concluded as below.1?The approach to improve the output performance of triboelectric nanogenerator was discussed from the capacitance model theory.Composite nano polymer film was prepared by filling the high dielectric constant barium titanate?BaTiO₃?nano-particles into room temperature vulcanized silicone rubber,which presented an effective way to improve the output performance of triboelectric nanogenerator from the view of modifying material dielectric property.Porous film was prepared by filling the foamable microsphere particles into room temperature vulcanized silicone rubber,which proposed a new approach to improve the output performance of triboelectric nanogenerator from the view of reducing the effective dielectric layer thickness.2?For the special application requirements of human motion energy harvesting,we designed and presented a lightweight,sustainable,effective,biocompatible and wearable textile-based flexible triboelectric nanogenerator using traditional“plain weave”.In order to further improve the output performance of triboelectric nanogenerator,a double-layer-stacked textile-based flexible triboelectric nanogenerator?DTET?was fabricated.A maximum output short-circuit current of 160?A and an open-circuit voltage of 600V can be obtained only by flapping the DTET with human palm.When the DTET was fixed at various parts of human body to harvest human motion energy,for example,under the arm or foot,or at the joint of the elbow or knee,the electric energy produced through walking,running or flapping.The electric energy can directly drive 100 LEDs connected serially,the competition timer,the digital clock and electronic calculator,which indicated that the DTET can be applied to drive self-powered illuminating devices and wearable electronics.Through acquiring the output signals of triboelectric nanogenerator,after rectification,amplification,counting and displaying,a movement monitoring equipment can be designed to count and display the number of movements.3?A unique core–shell coaxial structure triboelectric nanogenerator?CSTN?was fabricated with the self-made flexible electrode material and room temperature vulcanized silicone rubber.The CSTN can effectively convert various forms of human motion energy,such as pressing motion,twisting motion and bending motion energy into electric energy,with the advantages of flexibility,light weight,sustainability and biological compatibility.The CSTN can be used as an energy generation unit to harvest energy as well as a sensing unit to acquire motion information from different directions and adapt for the diverse motion situation.According to the characteristic of current multiplication,different numbers of CSTNs can be used as an effective power source for the different power requirements of the electronic devices,which can maximize energy utilization effectively.The core–shell coaxial structure triboelectric nanogenerator has a unique gasbag structure,making the device extremely sensitive to external force,and could generate different electric signal outputs with different bending and twisting angles.So a simple bending or twisting angle sensor function can be realized according to its signal outputs,which can also be used to detect the bending angle of body joint movement,which reveals the broad application prospects in human motion signal monitoring and health signal monitoring.