Stretchable, Washable, and Ultrathin Triboelectric Nanogenerators as Skin‐Like Highly Sensitive Self‐Powered Haptic Sensors

Abstract

Accompanying the boom in multifunctional wearable electronics, flexible, sustainable, and wearable power sources are facing great challenges. Here, a stretchable, washable, and ultrathin skin‐inspired triboelectric nanogenerator (SI‐TENG) to harvest human motion energy and act as a highly sensitive self‐powered haptic sensor is reported. With the optimized material selections and structure design, the SI‐TENG is bestowed with some merits, such as stretchability (≈800%), ultrathin (≈89 µm), and light‐weight (≈0.23 g), which conformally attach on human skin without disturbing its contact. A stretchable composite electrode, which is formed by homogenously intertwining silver nanowires (AgNWs) with thermoplastic polyurethane (TPU) nanofiber networks, is fabricated through synchronous electrospinning of TPU and electrospraying of AgNWs. Based on the triboelectrification effect, the open‐circuit voltage, short‐circuit current, and power density of the SI‐TENG with a contact area of 2 × 2 cm2 and an applied force of 8 N can reach 95 V, 0.3 µA, and 6 mW m−2, respectively. By integrating the signal‐processing circuits, the SI‐TENG with excellent energy harvesting and self‐powered sensing capability is demonstrated as a haptic sensor array to detect human actions. The SI‐TENG exhibits extensive applications in the fields of human–machine interface and security systems.

Flourishing energy harvesters for future body sensor network: from single to multiple energy sources

“…The evolution trend of the EHs in terms of growing systematic complexity (A) Emerging energy harvesters with versatile effects targeting different energy sources. Reprinted from ref (Chen et al, 2019c;Hu et al, 2019;Jiang et al, 2020c;Kim et al, 2020;Maharjan et al, 2019;Sun et al, 2020a) (Wang et al, 2020f) with permission, Copyrightª2020 Elsevier Ltd. (C) Self-powered strain sensing enabled by a flexible perovskite solar cell (PSC) and lithium-ion capacitor (LIC). Reprinted from ref with permission, Copyrightª2019 Elsevier Ltd. (D) A self-powered wireless sensor node via a TENG-based direct sensory transmission mechanism.…”

“…With the persistent efforts devoted to the advancement of the energy harvesting technologies, we have seen their evolution trend toward more capable and advanced systems. Single-source wearable EHs have experienced unprecedented development in the past decades, including but not limited to triboelectric ( Jiang et al., 2020c ), piezoelectric ( Kim et al., 2020 ), electromagnetic ( Maharjan et al., 2019 ), photovoltaic ( Hu et al., 2019 ), thermoelectric ( Sun et al., 2020a ), and biofuel cells ( Chen et al., 2019c ) as listed in Figure 7 A. Their mechanical property and output performance have been largely improved targeting for various wearable applications, and the hybridized EHs to further improve the energy conversion efficiency of a single source or to collect more energy from the surroundings have also been attaining growing attention.…”

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Figure 7 The evolution trend of the EHs in terms of growing systematic complexity (A) Emerging energy harvesters with versatile effects targeting different energy sources. Reprinted from ref ( Chen et al., 2019c ; Hu et al., 2019 ; Jiang et al., 2020c ; Kim et al., 2020 ; Maharjan et al., 2019 ; Sun et al., 2020a ) with permission, Copyright©2020 WILEY-VCH Verlag GmbH & Co, Copyright©2020 2020 Elsevier Ltd, Copyright©2019 Elsevier Ltd, Copyright©2019 The Royal Society of Chemistry, Copyright©2020 Springer Nature, Copyright©2019 WILEY-VCH Verlag GmbH & Co. (B) A self-powered wearable pressure monitoring system powered by a flexible thin-film thermoelectric generator. Reprinted from ref ( Wang et al., 2020f ) with permission, Copyright©2020 Elsevier Ltd. (C) Self-powered strain sensing enabled by a flexible perovskite solar cell (PSC) and lithium-ion capacitor (LIC).

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“… (A) Emerging energy harvesters with versatile effects targeting different energy sources. Reprinted from ref ( Chen et al., 2019c ; Hu et al., 2019 ; Jiang et al., 2020c ; Kim et al., 2020 ; Maharjan et al., 2019 ; Sun et al., 2020a ) with permission, Copyright©2020 WILEY-VCH Verlag GmbH & Co, Copyright©2020 2020 Elsevier Ltd, Copyright©2019 Elsevier Ltd, Copyright©2019 The Royal Society of Chemistry, Copyright©2020 Springer Nature, Copyright©2019 WILEY-VCH Verlag GmbH & Co. …”

Recent Progress of Nanogenerators Acting as Self‐Powered Drug Delivery Devices

“…Professor Zhong Lin Wang first proposed and developed the NG in 2006, realizing the conversion of mechanical energy into electrical energy. [ 12 ] In the past decade, a series of NG technologies, including piezoelectric nanogenerators (PENG), [ 13 ] triboelectric nanogenerators (TENG), [ 14 ] and pyroelectric nanogenerators (PYENG), [ 15 ] have been invented to make a great progress in self‐powered systems. There are a variety of mechanical energy, chemical energy and heat energy in human body, among which mechanical energy is the most common and abundant.…”