Wearable Piezoelectric Yarns with Inner Electrodes for Energy Harvesting and Signal Sensing

Abstract

Wearable device‐based gait data analysis is being used in medical research to prevent and treat serious diseases such as dementia beyond modern health management strategies. For gait‐related data collection and analysis, it is advantageous to place the sensor on the sole of the foot as a foot‐pressure, it is advantageous to use a piezoelectric generator‐based electronic textile (E‐textile) that can supply its own power by converting mechanical energy from the foot into electrical energy. In order to apply E‐textile materials to the sole of the foot, excellent durability, flexibility, and high signal accuracy through noise minimization are required. In this study, a piezoelectric polymer was used to coat the surface of a conductive fiber using the reverse dip coating technique. This method is easily scalable, feasible for large‐scale processing with a continuous process. The electrodes of this process are placed inside a piezoelectric fiber to minimize noise from the electrodes. The inner‐electrode piezoelectric yarn (IEPY) used during the process has excellent tensile strength (maximum stress and strain value: 54.2 MPa, 54%) and strong durability, maintaining its performance over 105 cycles under pushing force of 60 kg and generating excellent piezoelectric output (292 mVmax, 16.2 µW). The IEPY can drive the sensor for gait data, with the sensors being capable of continuous and large‐scale operation and feasible for the manufacturing of custom sensors.

A Review on Wearable Product Design and Applications

“…Ryu et al [93] applied a piezoelectric wearable device on a human foot for energy generation and signal detection. First, an Inner-Electrode Piezoelectric Yarn (IEPY) piezoelectric filament was created.…”

Elastic Kernmantle E‐Braids for High‐Impact Sports Monitoring

“…The significance of converting human-mechanical energy into electricity motivates the exploration for cutting-edge energy-conversion technologies. Despite the numerous available working mechanisms the yarnbased energy harvesters are mainly developed from such as electromagnetic effect [24,25] and piezoelectric effect, [26,27] an emerging triboelectric nanogenerator (TENG) utilizing the coupling effect of electrostatic-induction and contact-electrification has enabled widespread applications in low-frequency mechanical energy harvesting and self-powered sensing. [28][29][30] With the advantages of light-weight, easy implementation, and high output, TENG technique displays attractive possibility in the field of soft electronics, where large amounts of distributed monitoring devices must be applied.…”

A Dual‐Functional Triboelectric Nanogenerator Based on the Comprehensive Integration and Synergetic Utilization of Triboelectrification, Electrostatic Induction, and Electrostatic Discharge to Achieve Alternating Current/Direct Current Convertible Outputs

“…DOI: 10.1002/adma.202208139 electric power have been systematically studied, including thermal generators, [3,4] piezoelectric nanogenerators, [5,6] electromagnetic generators, [7,8] and triboelectric nanogenerators (TENGs). [9,11] Among them, TENGs demonstrate a number of distinct advantages due to their simple working mechanism and structure, such as, light weight, [12,13] low cost, [14,15] and superior performance in high-entropy environmental energy harvesting.…”