Research On Triboelectric Nanogenerator And Self-powered Strain Sensor Based On MXene Composite Film

Strain sensor is a kind of sensor based on measuring the strain produced by the deformation of an object.At present,most of the pressure sensors on the market require an external power supply.On the one hand,the volume and mass of the sensors are increased.On the other hand,the existing problems of highly cost,environmental pollution,and limited application scenarios largely restrict the development of the sensors.Sensors based on triboelectric nanogenerator(TENG)can not only directly convert the mechanical energy of human body into electrical signals,but also overcome various drawbacks driven by the traditional sensors with heavy external power sources.It might undoubtedly provide an effective solution for the efficient energy supply of the sensor.However,the existing methods for combining TENG electrodes with triboelectric layer materials may be too simple,thus making the bonding between the electrodes and the triboelectric layer not tightly enough and affecting the speed and efficiency of electron transfer;or the fabrication procedures are too complicated and require expensive equipment,resulting in cost-ineffective and difficult-to-large-scale fabrication.Therefore,it is urgently needed to explore a simple and direct method for preparing a material with a tightly bonded electrode and triboelectric layer.Our research has found that by using vacuum filtration,a film with tightly combined electrode and triboelectric layer can be prepared.By using MXene nanosheets as the electrode/triboelectric layer and PTFE as the triboelectric layer,TENG based on MXene-PTFE(MP)is prepared.After adding PEDOT:PSS to modify MXene,the rate and efficiency of charge transfer between the electrode and the triboelectric layer are enhanced,thereby improving the performance of TENG.This work used the integrated MXene-PEDOT:PSS/PTFE(MPP)film to investigate the performance when applied to fabricate a TENG sensor.The performance tests of TENG prepared based on MP and MPP films were carried out.The experimental results found that the TENG prepared based on MPP films has better cycle stability(no attenuation after 6000 cycles),higher electrical signal output under the action of external forces(increase the voltage from 8 V to 13.8 V),and there is a better response relationship between voltage and forces.The self-powered strain sensor based on MPP-TENG has high sensitivity,especially for subtle force sensitivity(>6.05V·N^-1),an extremely short response time(52 ms)and recovery time(34ms),and excellent stability(over 6000 cycles),which have broad application prospects in biomedicine and health monitoring.Meanwhile,the preparation method is suitable for most conductive nanomaterials.Other commercial films can also be chosen as the triboelectric layer,such as cellulose and Mixed fiber resin(MFR)films.The preparation method provides a simple and valuable new idea for preparing TENG materials with stable electrode-triboelectric layer interface.