The effective conversion of vibrational energy from the motion of human body into electricity has been considered as one of the most promising technologies for charging portable electronic devices. Here, we report an electric polarization-controlled PVDF-based hybrid triboelectric-piezoelectric nanogenerator (TP-NG) as for an effective energy harvesting of various mechanical vibrations from human foot. The hybrid TP-NG simply consists of PVDF, Al, and acrylic, and the triboelectric NG component is vertically stacked on the piezoelectric NG component. We observed the strong electric-polarization-dependent electric power due to the modulated surface potential and negative piezoelectricity of PVDF. We also observed the in-phase power generation due to the vertical stacking of two flat NGs, irrespective of various loading rate, contact time, force, and frequency. Three hybrid TP-NGs were embedded at the forefoot, arch, and heel positions in a shoe insole. During normal walking, the shoe insole generated sufficient power to operate light-emitting diodes, which could be used in lightning at night. In addition, the insole operated a wireless pressure network, which could be used in monitoring and transmitting the pressure distribution on the foot to a cellular phone. This work provides an important step in the harvesting of random and irregular vibrational energy from the human foot, and in the realization of self-powered lightning for safety and self-powered wireless pressure monitoring system for diagnostic healthcare.
Bibliographical noteFunding Information:
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology ( 2019R1F1A1058514 and 2016M3A7B4910940 ). G-H.L. also acknowledges the support from the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) ( 20173010013340 ). H.S.K. and H.-C.S. would like to acknowledge the support from the National Research Council of Science & Technology (NST) grant by the Korea government ( MSIP ) (No. CAP-17-04-KRISS ). G.M. appreciates the financial support from La Caixa Foundation under the Junior Leader Retaining Fellowship ( LCF/BQ/PR19/11700010 ) and EnSO project, accepted for funding within the Electronic Components and Systems For European Leadership Joint Undertaking in collaboration with the European Union's H2020 Framework Programme ( H2020/2014–2020 ) and National Authorities , under grant agreement no. 692482 .
© 2020 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Electrical and Electronic Engineering