Embroidery Triboelectric Nanogenerator for Energy Harvesting

Abstract

Triboelectric nanogenerators (TENGs) are devices that efficiently transform mechanical energy into electrical energy by utilizing the triboelectric effect and electrostatic induction. Embroidery triboelectric nanogenerators (ETENGs) offer a distinct prospect to incorporate energy harvesting capabilities into textile-based products. This research work introduces an embroidered triboelectric nanogenerator that is made using polyester and nylon 66 yarn. The ETENG is developed by using different embroidery parameters and its characteristics are obtained using a specialized tapping and friction device. Nine ETENGs were made, each with different stitch lengths and line spacings for the polyester yarn. Friction and tapping tests were performed to assess the electrical outputs, which included measurements of short circuit current, open circuit voltage, and capacitor charging. One sample wearable embroidered energy harvester collected 307.5 μJ (24.8 V) of energy under a 1.5 Hz sliding motion over 300 s and 72 μJ (12 V) of energy through human walking over 120 s. Another ETENG sample generated 4.5 μJ (3 V) into a 1 μF capacitor using a tapping device with a 2 Hz frequency and a 50 mm separation distance over a duration of 520 s. Measurement of the current was also performed at different pressures to check the effect of pressure and validate the different options of the triboelectric/electrostatic characterization device. In summary, this research explains the influence of embroidery parameters on the performance of ETENG (Embroidery Triboelectric Nanogenerator) and provides valuable information for energy harvesting applications.

Keywords: ETENGs (embroidered triboelectric nanogenerators); electrostatic characterization device; embroidered stitch length; energy extraction; energy harvesting; tapping and sliding devices; wearable electronics.

Figure 1

Biomechanical power sources for wearable energy harvesting generators involve techniques such as bending of the elbow, compressing of the knee, pressing of the heel, and generating friction on the side torso.

Figure 2

Schematic diagrams of charge transfer mechanisms. (a) Electron transfer mechanism; (b) ion transfer mechanism.

Figure 3

Triboelectric series shows the comparative tendency of materials to either gain or lose electrons.

Figure 4

The four fundamental working modes of TENG. (a) The vertical contact–separation mode. (b) The lateral sliding mode. (c) The single electrode mode. (d) The free-standing mode.

Figure 5

Schematic diagram of the (a) embroidery machine and (b) embroidery.

Figure 6

Different parameters to control the surface morphology of ETENG, Inkstitch v3.0.1 (an extension of Inkscape software).

Figure 7

Surface morphology of ETENG.

Figure 8

(a) The main sample made by 100% Polyester yarn embroidering on conductive fabric, (b) magnified view.

Figure 9

(a) Tapping characterization device used to characterize ETENG (b) Schematic diagram of the tapping device.

Figure 10

Sliding test device setup for characterization of the embroidery TENG.

Figure 11

(a) Schematic diagram of a rectifier circuit for energy harvesting in a capacitor, (b) rectifier circuit with capacitor.

Figure 12

Experimental results of tapping test average maximum open circuit voltage and average maximum short circuits current.

Figure 13

Maximum power density and surface charge generated in 60 s by tapping test in 2 Hz frequency.

Figure 14

The harvested voltage in 1 μF capacitor during the tapping test.

Figure 15

The harvested voltage of sample ETFS2.3 in 1 μF capacitor for tapping test throughout 520 s.

Figure 16

External load resistance to obtain the maximum power density.

Figure 17

Experimental results of average maximum open circuit voltage and average maximum short circuits current for the sliding test.

Figure 18

Maximum power density and surface charge generated in 60 s for sliding test.

Figure 19

Harvested voltage in 4.7 μF capacitor by sliding at 1.5 Hz frequency.

Figure 20

The harvested voltage of sample ETFS3.1 in different capacitance capacitors.

Figure 21

(a) Rectifier circuit for energy harvesting in capacitor, (b) lighted LEDs by harvested energy.

Figure 22

Measurement of the short current at different pressures.

Figure 23

Energy harvesting from human kinetics by generating friction on the side torso.

Figure 24

Output performance after washing: (a) short circuit current, (b) capacitor charging of 1 μF.

Figure 25

Optical microscope image of ETENG after 30 h of washing.

Figure 26

Martindale test for the mechanical durability of ETENG.