Triboelectrification-Induced Electricity in Self-Healing Hydrogel for Mechanical Energy Harvesting and Ultra-sensitive Pressure Monitoring

Abstract

Triboelectric nanogenerators (TENGs) have shown huge application potential in the fields of micro–nano energy harvesting and multifunctional sensing. However, the damage of triboelectric material is one of the challenges for their practical applications. Herein, we fabricated a flexible TENG employing self-healing hydrogel and fluorinated ethylene propylene film as triboelectric materials for mechanical energy harvesting and pressure monitoring. The prepared hydrogel not only has excellent flexibility, transparency, and self-healing property but also exhibits good mechanical property without plastic deformation and damage under a large stretchable strain of 200%. The output electric signals of TENGs are as high as 33.0 V and 3 μA under a contact frequency of 0.40 Hz and a pressure of 2.9 N, respectively, which can charge a capacitor of 0.22 μF to 24.3 V within 300 s. Note that the voltage retention rate of TENGs after self-healing is up to 88.0%. Moreover, hydrogel-based TENGs can act as a wearable pressure sensor for monitoring human motion, exhibiting a high sensitivity of 105.9 mV/N or 1.73 nA/N under a contact frequency of 0.40 Hz. This research provides a reference roadmap for designing TENGs and self-powered pressure sensors with flexibility, self-healing, and robustness.

Liquid Metal Nanoparticles Physically Hybridized with Cellulose Nanocrystals Initiate and Toughen Hydrogels with Piezoionic Properties

“…Normalizing by the area of touch (4 cm 2 ), this translates to a current density of 9.55 μA/cm 2 . Such a large electrical current and current density are similar to those of previous high-performance hydrogel touch sensors and triboelectric energy harvesters that use hydrogel electrodes, − ,,− yet the gels here are simple to make and have attractive mechanical properties.…”

Self‐Healable Triboelectric Nanogenerators: Marriage between Self‐Healing Polymer Chemistry and Triboelectric Devices

“…[ 161 ] The rich structural designability and self‐healing properties of hydrogels promote the application in conductive electrodes of TENG devices. [ 162,163 ]…”

“…[161] The rich structural designability and self-healing properties of hydrogels promote the application in conductive electrodes of TENG devices. [162,163] The first application of self-healing hydrogels as conductive electrodes in TENG devices dates back to 2017, when Parida et al [39] fabricated a self-healing TENG by cross-linked poly(vinyl alcohol) (PVA) gel using the electrode and commercial VHB tape using the friction layer, in which sodium tetraborate was introduced into the PVA cross-linked network to act as the cross-link of hydrogen bonds for ionic conduction. The fabricated TENG was stretchable, transparent, and repairable with 12 times the energy harvesting performance over Agbased electron collectors.…”

Recent progress in self-healable energy harvesting and storage devices – a future direction for reliable and safe electronics

“…Taking reference from previous research, many SH polymers have been investigated for versatile applications like energy harvesting and storage devices, electronic skin (E-skin), etc. [9][10][11][12] Over the past decade, various SH-based electrodes and electrolytes have been tremendously developed, which can identify the damage and repair themselves. Therefore, SH polymers are ideal candidates for the next generation of electronics.…”