Highly sensitive, self-powered and wearable electronic skin based on pressure-sensitive nanofiber woven fabric sensor

Abstract

The wearable electronic skin with high sensitivity and self-power has shown increasing prospects for applications such as human health monitoring, robotic skin, and intelligent electronic products. In this work, we introduced and demonstrated a design of highly sensitive, self-powered, and wearable electronic skin based on a pressure-sensitive nanofiber woven fabric sensor fabricated by weaving PVDF electrospun yarns of nanofibers coated with PEDOT. Particularly, the nanofiber woven fabric sensor with multi-leveled hierarchical structure, which significantly induced the change in contact area under ultra-low load, showed combined superiority of high sensitivity (18.376 kPa−1, at ~100 Pa), wide pressure range (0.002–10 kPa), fast response time (15 ms) and better durability (7500 cycles). More importantly, an open-circuit voltage signal of the PPNWF pressure sensor was obtained through applying periodic pressure of 10 kPa, and the output open-circuit voltage exhibited a distinct switching behavior to the applied pressure, indicating the wearable nanofiber woven fabric sensor could be self-powered under an applied pressure. Furthermore, we demonstrated the potential application of this wearable nanofiber woven fabric sensor in electronic skin for health monitoring, human motion detection, and muscle tremor detection.

Significance of Nanomaterials in Wearables: A Review on Wearable Actuators and Sensors

“…[100][101][102][103][104] Lou et al [100] have electrospun poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) nanofibers and encapsulated them with reduced graphene oxide (rGO) to form a rapid responsive pressure sensor. To date, there are typically three approaches to fabricate electrospun functional nanofibers for the realization of sensitive wearable sensors: (i) directly electrospin conductive polymers into functional nanofibers, [105,106] such as PEDOT:PSS, [107] poly aniline (PANI), [108] (ii) directly electrospin nanofibers by doping poly mer spinning solutions with graphene oxide, carbon, CNTs, or Cu, Ag nanoparticles, or (iii) electrospin nonconductive polymers into nanofibers first and then coat them with conductive materials by electron beam evaporation, [109] electroless deposition, electrochemical polymerization, in situ polymerization, [92,110] and so on. Strain sensor based on CNT and shape memory polymers has reported an impressive strain rate over 700% [103] strain and vacuum filtration based graphene nanopaper prepared by Yan and team [104] has shown strain rate over 100%.…”

Fiber/Fabric‐Based Piezoelectric and Triboelectric Nanogenerators for Flexible/Stretchable and Wearable Electronics and Artificial Intelligence

“…The simplest 2D fabric‐based PENGs are directly woven from one type of piezoelectric fibers. For instance, a wearable and self‐powered fabric‐based PENG as a highly pressure‐sensitive electronic skin was woven from PEDOT‐coated PVDF electrospun yarns ( Figure a) . The high sensitivity of the fabric‐based electronic skin was attributed the accumulation of PEDOT nanoparticle doped PVDF nanofibers which increased the contact joints and the total contact area under subtle stress.…”

Recent Advances in 1D Stretchable Electrodes and Devices for Textile and Wearable Electronics: Materials, Fabrications, and Applications

“…To date, some of the typical 1D stretchable electronic devices are mechanical sensors that measure a strain, pressure, bending, torsion sensor, and so on. Among these, because of the simplicity of sensor design, various strain sensors based on 1D stretchable electrodes have been developed . In particular, most existing 1D stretchable electrodes themselves that are made by the coating or percolation of conductive materials in an elastomeric matrix can be readily used as a resistive strain sensor by means of the strain‐dependent changes in their electrical conductivity.…”