Flexible and sensitive piezoresistive electronic skin based on TOCN/PPy hydrogel films

Abstract

In recent years, the wearable electronic skin (E‐skin) has attracted more and more attention due to high sensitivity, good portability and flexibility. In this work, we used the 2,2,6,6‐tetramethylpiperidinyl‐1‐oxyl (TEMPO)‐oxidized cellulose nanofibril (TOCN) as the substrate, and used the in‐situ polymerization method to introduce polypyrrole (PPy) into the TOCN substrate. Then, the nylon gauze was used as microstructure template to prepare a TOCN/PPy E‐skin with a surface microstructure. This E‐skin possessed excellent sensing and mechanical properties. In the pressure range of 0–600 Pa, the sensitivity of E‐skin was 3.13 kPa−1. In addition, the E‐skin exhibited ultrafast response/recovery time (≤10 ms), ultralow detection limit of 0.3 Pa, good stability (>9000 cycles) and mechanical strength of up to 117 MPa. Therefore, the TOCN/PPy E‐skin has broad development prospects in the fields of artificial intelligence and health monitoring.

Cellulose Nanopaper: Fabrication, Functionalization, and Applications

“…Gao et al introduced PPy into TEMPO-oxidized CNFs (TOCN) through in situ polymerization and then prepared TOCN/PPy electronic skin with surface microstructure with nylon gauze as microstructure template, as shown in Fig. 4 a [ 124 ]. The prepared electronic skin exhibited excellent sensing and mechanical properties.…”

“…4 a Schematic illustration of the flexible E-skin preparation. b Real-time I-t curves of wrist bending, and c finger bending [ 124 ]. d Schematic representation of the fabrication of the transparent bacterial celluloses/MXene film with Janus structure.…”

Fabrication of conductive and superhydrophobic poly(lactic acid) nonwoven fabric for human motion detection

“…With the rapid development of emerging industries such as touchable displays, 1 electronic skins, 2 intelligent robotics, 3 and wearable devices, 4 sensors as the most important components have been paid enormous attention. According to the difference of function, pressure sensors can be divided into piezoresistive pressure sensor, 5,6 capacitive pressure sensor, 7 and piezoelectric pressure sensor 8 . As one of the important representatives, piezoresistive pressure sensor is promising in wearable devices because of their high sensitivity, fast response, cost‐effective process, and simplified signal collection 9 .…”

A Multifunctional Skin‐Like Sensor Based on Liquid Metal Activated Gelatin Organohydrogel

“…Particularly, most of the conductive hydrogels are comparing conductive nano-fillers (e.g., metal nano wire, [9,10] graphene, [11] carbon nanotubes, [12] and Perovskite [13] ) and polymer networks. [14,15] The mechanical mismatch between the rigid filler and soft polymer bulk will lead to concentrated internal stress and further affect the performance and lifetime of conductive hydrogel.In the past decade, liquid metals (LMs) [16][17][18] are emerging as novel conductive fillers for soft electronics, and among them, eutectic gallium and indium alloys (EGaIn) are the most widely used due to their negligible toxicity, low cost, and good thermal and electrical conductivity. More importantly, the melting point could be controlled below room temperature by appropriately adjusting the ratio of the Ga and In components, thus rendering EGaIn excellent ductility and fluidity to address the issues caused by rigid conductive fillers.…”

“…Particularly, most of the conductive hydrogels are comparing conductive nano-fillers (e.g., metal nano wire, [9,10] graphene, [11] carbon nanotubes, [12] and Perovskite [13] ) and polymer networks. [14,15] The mechanical mismatch between the rigid filler and soft polymer bulk will lead to concentrated internal stress and further affect the performance and lifetime of conductive hydrogel.…”