Piezoelectric-Driven Self-Powered Patterned Electrochromic Supercapacitor for Human Motion Energy Harvesting

Abstract

The rapid development of a self-powered system (SPS) has aroused an increasing interest in the field of wearable electronics. The current development trend in wearable electronics is toward integration, portability, miniaturization, and sustainability. Hence, a wearable piezoelectric-driven self-powered patterned electrochromic supercapacitor (ESC) is presented here, which is integrated with the energy harvesting, conversion, storage and indication technologies. The patterned polyaniline (PANI) electrodes electrodeposited by coupling cyclic voltammetric and galvanostatic (CV-GS) techniques were assembled as patterned ESC, which served to store the energy and indicate the charging/discharging status simultaneously. With the advantages of flexibility and biocompatibility, the polyvinylidene difluoride (PVDF) nanofibers were fabricated by electrospinning to establish the piezoelectric nanogenerators (PENGs) as the energy-harvesting device, which can be attached to human body to harvest mechanical kinetic energy. The integrated wearable self-powered system (SPS) can harvest human motion energy and other mechanical energy, then transfer the mechanical energy to electric energy by a rectifier for charging ESC, which provides a sustainable energy supply for wearable electronics. It is foreseen that the self-powered patterned ESC that we proposed will have a broad application in the fields of flexible artificial skin, smart robots, artificial intelligence, and implantable or portable medical devices.

A Review of Piezoelectric PVDF Film by Electrospinning and Its Applications

“…Electrochromic supercapacitors (ECS) were also prepared with electrospun PVDF film by He et al [ 157 ]. To obtain the ECS, PANi was used to achieve visual electrochromic performance and energy storage.…”

“…( d ) The equivalent circuit of the self-powered patterned ESC. Reprinted with permission from [ 157 ].…”

Electrode Materials for Supercapacitors: A Review of Recent Advances

“…FSCs have commanded a lot of concentration as one of the most important energy storage research focuses owing to their extraordinary capacitive behaviour, higher power density, higher rate capability, and higher cyclic stability in comparison with batteries and higher E d compared to the traditional capacitors [476], which provide them with a vast range of potential to be utilized in various applications. Each category of SC has its own specific features and applications, such as in portable/wearable electronic devices as well as in computer and mobile phones [2,477], high power sources for heavy lift trucks or cranes [478,479], the self-powered SCs in medical applications (e.g., flexible artificial skin, artificial intelligence, portable or implantable medical/biomedical devices) [480,481], solar applications [482][483][484]. There are several SC companies such as ELTON (Russia), Nesscap (Korea), CAP-XX (Australia), and Nippon Chemicon (Japan), which are developing various kind of SCs for different applications [485].…”

Stretchable Supercapacitors as Emergent Energy Storage Units for Health Monitoring Bioelectronics

“…[240,241] For example, a self-powered device with wearable PENG and electrochromic supercapacitor was reported for the immediate visualization of energy level. [242] Using PVDF nanofibers as the piezoelectric material, kinetic energy from human body, including elbows, knees, and feet during walking and running, was collected to charge a supercapacitor, as shown in Figure 13a. After four self-charging and discharging cycles for 50 s, the voltage of supercapacitor increased to 0.231 V. In another work, Maitra et al fabricated a PENG using natural biomaterials, namely fish swim bladder, to collect electricity from human body motions and charge supercapacitors to 281.3 mV in 80 s. [243] …”

“…Energy Mater. [242] Copyright 2019, American Chemical Society. Other energy harvesting strategies and corresponding applications based on different energy conversion including piezoelectric effect, photovoltaic effect, thermoelectric effect, and electromegnatic induction, as indicated.…”