Study On Triboelectric Nanogenerators Based On Stretchable And Healable Hydrogel Electrode

In recent years,with the rapid development of innovative technologies,wearable electronic devices with multiple functions such as transparency,stretchability,biocompatibility,healable capability,and biodegradability have broad application prospects.However,most of the existing power devices can hardly match the multifunctionality of these electronic products,so their rapid development has been severely hampered.In order to meet the power consumption requirements of the electronic devices mentioned above,it is extremely urgent to develop of energy devices possessing the comparable functionalities.Recently,triboelectric nanogenerator(TENG),as a new energy harvesting device,have attracted extensive attention owing to its low cost,high-efficiency,environmentally-friendly and wide applications in various energies harvesting and selfpowered sensors.So far,efforts have been made to develop multifunctional TENGs,such as stretchable,transparent,healable,or biodegradable TENGs.However,for practical applications,diverse working environments require people to continue to develop multifunctional TENG.Among diverse materials of TENG,the hydrogel with excellent mechanical properties,biocompatibility,biodegradability,and super healable capability might be a good candidate to endow TENG with similar performance characteristics.Based on the above problems,the main conclusions are as follows:Firstly,the desired ionic hydrogels(PLG-LiCl)with high tensile properties and self-healing ability were prepared by in-situ co-polymerization.The hydrogel exhibited high breaking strength with graphene oxide(GO)and Laponite as the physical cross-linking points.The hydrogel with 1 wt%GO achieved a tensile strength of 106 k Pa and an ultimate tensile strain of 1356%,the glass transition temperature is 50.6℃,and the ionic conductivity is 38.8 m S/cm at 25℃.Hydrogen bonding and electrostatic interaction between the GO,Laponite and polymer molecular chains make hydrogels have high healable efficiency,which can reach 99%after healing at 80℃for 36 h.And the existence of hydrogen bonds can dissipate a large amount of energy,so that the PLG-LiCl hydrogel also has good resilience performance and fatigue resistance.In addition,the hydrogel also has ultra-fast electrical healable properties.Second,an ultra-stretchable and healable hydrogel-based triboelectric nanogenerator(TENG)was designed and fabricated for mechanical energy harvesting and self-powered sensor for human motion monitoring and pressure sensing.The TENG in this work demonstrates an open-circuit voltage of 75 V,a short current of 0.6μA,and a short-circuit charge of 25 n C.The maximum output power density reaches up to 260 m W/m~2.When using the hydrogel and 3M VHB9469 film as the electrode and dielectric layer,The TENG can operate normally at 500%tensile strain;while the electrical output of the TENG can fully recover to the initial value after healing the damages.This hydrogel-based TENG is demonstrated to power wearable electronics,and is used as self-powered sensor for human motion monitoring and pressure sensing.This work shows opportunities for multifunctional power sources and potential applications in wearable electronics.