Research On The Design Of Triboelectric-electromagnetic Hybrid Nanogenerator For High-efficeient Energy Harvesting

In recent years,with the maturity and popularization of 5G technology,the technology of Internet of things(IoT)will gradually infiltrate in all aspects of our lives.However,in the process of IoT popularization,energy supply for wireless monitoring network nodes has become an urgent problem.Due to shortcomings of service life and environmental pollution,traditional chemical batteries are no longer suitable for the development trend of IoT power supply.New energy harvesting devices with good environmental adaptability,high output performance,and long service life are prepared by integrating triboelectric nanogenerator(TENG)with electromagnetic generator(EMG),which can convert mechanical energy into electrical energy to power the sensor network.There are many forms of mechanical energy in nature,such as wind energy,mechanical equipment vibration energy,and wave energy.If these widely distributed and easy to convert energy can be collected and converted into electrical energy,which can meet the energy consumption requirements of electronic equipment.In this paper,to meet actual demand of energy supply of electronic equipment in the IoT,we have proposed some triboelectric-electromagnetic hybrid nanogenerators with different structures.By integrating TENG and EMG,the frequency response bandwidth of the hybrid nanogenerator is broaden.The main work of this paper includes:A triboelectric-electromagnetic hybrid nanogenerator with high efficiency for wind energy harvester based on the cam structure is proposed and constructed.By integrating two different power generation technologies into one device structure,the device has characters of high output performance,high conversion efficiency and wide frequency response.The device generator unit consists of two groups of TENG and two groups of EMG.The negative material and positive material are room temperature vulcanized silicone rubber(RTV)and Al.The vertical contact-separation structure design is used to avoid the damage of the friction material surface achieving the stability of the mechanical performance and electrical output performance of the device;EMG is designed with a relative rotation structure between coils and magnets.Wind energy is converted into rotational kinetic energy through the cam structure,thereby generating an induced current.The hybrid nanogenerator constructed in this chapter can not only provide power output for commercial electronic products,but also provide stable power output for t wireless monitoring system by ourselves at the wind speed of 12m/s.Aiming at the problem that most of the auxiliary components(springs,cantilever beams,etc.)currently lead to low utilization of the structure space,a self-powered portable triboelectric-electromagnetic hybrid nanogenerator for vibration mechanical energy harvesting designed and prepared.The generator is designed as a cylinder structure with a dimension of ? 70 mm × 50 mm.The energy capture structure is composed of two helical structures and an oblate magnet located in the middle.The spiral structure acts both as a magnet support structure and works as a carrier of friction film.The maximum output power of TENG and EMG is 0.88 mW and 216.7 mW,respectively.In addition,combined with the requirements of designing application scenarios,commercial blue LED and thermohygrographs are selected for physical demonstration.TENG and EMG can drive 75 LEDs in series and 189 LEDs in parallel to work normally,respectively.With the aid of energy management circuit,the device can realize continuous power supply to two thermohygrographs in series.Under external vibration conditions,the device can achieve the purpose of self-powered design of the wireless sensor monitoring system,and transmit the data to the mobile phone monitoring terminal through wireless transmission technology.In order to solve the problem of single degree of freedom for most energy harvesters,a triboelectric-electromagnetic hybrid nanogenerator with multiple degrees of freedom is proposed and fabricated.The energy harvester adopts a spherical structure design.When the external load resistance is about 200 M? and 1 K?,the maximum output power of TENG and EMG is 18 ?W and 640 ?W,respectively.Through the analysis of the output response of each power generation unit at different excitation frequencies,it is known that the output performance of device increases with the increase of the external excitation frequency,and the maximum output open circuit voltages of TENG and EMG are 88 V and 3.75 V.The device can directly light up 200 green LEDs during the process of reciprocating motion,and drive a commercial temperature and humidity meter with the aid of capacitor.