An Ultrathin Flexible Single‐Electrode Triboelectric‐Nanogenerator for Mechanical Energy Harvesting and Instantaneous Force Sensing

Abstract

The trends in miniaturization of electronic devices give rise to the attention of energy harvesting technologies that gathers tiny wattages of power. Here this study demonstrates an ultrathin flexible single electrode triboelectric nanogenerator (S‐TENG) which not only could harvest mechanical energy from human movements and ambient sources, but also could sense instantaneous force without extra energy. The S‐TENG, which features an extremely simple structure, has an average output current of 78 μA, lightening up at least 70 LEDs (light‐emitting diode). Even tapped by bare finger, it exhibits an output current of 1 μA. The detection sensitivity for instantaneous force sensing is about 0.947 μA MPa−1. Performances of the device are also systematically investigated under various motion types, press force, and triboelectric materials. The S‐TENG has great application prospects in sustainable wearable devices, sustainable medical devices, and smart wireless sensor networks owning to its thinness, light weight, energy harvesting, and sensing capacities.

Triboelectric Nanogenerators for Mechanical Energy Harvesting

“…In 2017, a flexible (transparent and non‐transparent) TENG was fabricated by Chen; it could harvest mechanical energy and be used as force sensor. The non‐transparent TENG consisted of three layers (i.e., PTFE, Al, and PET) as the triboelectric layer, electrode layer, and substrate layer, respectively.…”

“…[8] Thee lectrostatic induction effect, which is used to generatee lectricity,h as crucial improvement in the TENG working. Thet riboelectric charges are induced on the back sideo ft he conductive electrodes.T he inducedc harges on the back side of the electrodes providem obile charges; when these two materials make ar elative motion, they acquires opposite chargesd ue to the consistentf low of induced charges electric potential that is created between these two electrodes.T herefore,m echanical energy is converted into electrical energy.T here are various forms of relative motion in the movement of the TENG to harvest mechanicale nergy are vertical contactm ode, lateral sliding mode, [56][57][58][59][60][61][62][63][64][65] single electrode mode, [66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84] and free standing triboelectric layer mode, [85][86][87][88][89][90][91][92][93][94][95] as shown in Figure 2.…”

“…In 2017, af lexible (transparent and non-transparent) TENG was fabricated by Chen; [74] it could harvest mechanical energy and be used as forces ensor. Then on-transparent TENG consisted of three layers (i.e., PTFE, Al, and PET) as the triboelectric layer, electrodel ayer, and substrate layer, respectively.W hile the transparent TENG also had three layers:f luorinated ethylene propylene (FEP), an indium tin oxide (ITO) layer, and ap olypropylene (PP) layer as the tribo-electric surface,e lectrodel ayer, and substrate layer, respectively.W hen the TENG was pressed by latex-glove-covered human palm, the peak output current and voltage were observedt ob e7 8mAa nd 340 V, respectively,a nd had the capacity to light 70 LEDs.W hen the TENG acted as af orce sensor, it had ad etection sensitivity of 0.947 mAMPa À1 .D ue to the simple,l ight-weight,a nd flexible structure,t he TENG has potential for many applications in the fabrication of sensing systemsand wearable electronics.…”

Modulation of surface physics and chemistry in triboelectric energy harvesting technologies

“…In this respect, an energy harvesting technology is newly emerging as one solution that can substitute or supplement the existing batteries [5][6][7][8][9][10]. Especially, a flexible type of mechanical energy harvester converting the kinetic energy into the electricity has attracted much attention because it can provide the sustainable energy in isolated, indoor environment and biomechanical conditions [11][12][13][14][15][16][17].…”

A Self‐Powered Dynamic Displacement Monitoring System Based on Triboelectric Accelerometer

“…[7] The output voltage is a direct measurement of the gap distance, while the output current represents the impact speed. [8][9][10][11][12][13][14][15][16][17][18][19][20] In this study, based on the noncontact freestanding TENG, a novel self-powered accelerometer sensor with the sleeve-tube structure for vibration detection is proposed and fabricated. [6] TENGbased sensors have been demonstrated for sensing of motion, pressure, velocity, instantaneous force, and human triggering.…”