Triboelectric Nanogenerator Based on Copper Foam with Graded Porous Architectures for Energy Harvesting and Human Motion Monitoring

With the rising development of the Internet of Things(IoTs) andartificial intelligence, triboelectric nanogenerators (TENGs) haveshown great application potential to dramatically improve our dailylives as self-powered sensors in portable and wearable electronics.In this study, copper foam with graded porous architectures (CFGA),featuring interconnected micro- and nanoporous composite structures,has been developed via a cost-effective and convenient industrialstrategy, including electro galvanizing, thermal diffusion, and corrosionmethods in sequence. Based on the measurement and evaluation of compressedforce, frequency, and reliability, the obtained CFGA can enlarge thecontact surface areas and improve the output performance of TENG effectivelyas a positive electrode. The results show that TENG based on CFGAcan yield an open-circuit voltage and a short circuit current of ashigh as 45.8 V and 1.88 mu A, respectively. The correspondingmaximum output peak power can reach similar to 52.9 mu W. For practicalapplication, CFGA-TENG can be designed in a spacer-free structurefor keyboards with the function of electronic code lock. Meanwhile,it can also be applied in smart shoe insoles as a self-powered CFGA-TENGsensor array for human motion monitoring in real time. Our work providesan industrial production approach for functional electronics as energyharvesters and sensors and makes it more accessible for practicalapplications.