Ultrastretchable, Adhesive, Fast Self-Healable, and Three-Dimensional Printable Photoluminescent Ionic Skin Based on Hybrid Network Ionogels

Abstract

Developing multifunctional stretchable ionic skin (I-Skin) to mimic the sensations of the human skin is of great interest and shows promising potential in wearable sensors and human−machine interfaces (HMIs). However, common ionogels prepared with small-molecule cross-linkers and single networks can hardly satisfy the requirements of adjustable mechanical properties, strong adhesion, fast self-healability, and good stability in extreme environments. Herein, an ultrastretchable (>10,000%), ultrastrong adhesive (>6.8 MPa), ultrafast selfhealable (10 s), high thermally stable (−60 to 250 °C), and three-dimensional (3D)-printable photoluminescent ionogel with shape memory properties has been designed. The ionogel consists of hyperbranched polymer covalent-cross-linked poly(zwitterionic ionic liquid)-co-poly(acrylic acid) and multiple dynamic bonding cross-linked networks. The excellent performance of the ionogel-based high-stretchable strain sensor and the triboelectric nanogenerator (TENG)-based self-powered touch sensor is further demonstrated over a wide temperature range (−40 to 150 °C). More importantly, ionogel-based I-Skin can work as an HMI for human gesture recognition and real-time wireless control of robots under extreme vacuum conditions and can also self-heal immediately along with function recovery after mechanical damage.

Poly(N,N-dimethyl)acrylamide-based ion-conductive gel with transparency, self-adhesion and rapid self-healing properties for human motion detection

“…The self-healing mechanism of the ion-conductive gel may be due to the dynamic ion–dipole interaction formed between the CO in DMA and the cation [BMIM] in the ionic liquid and the formation of dynamic hydrogen bonding between –CF 3 and the anion [Tf 2 N]. 36,63…”

Object recognition by a heat-resistant core-sheath triboelectric nanogenerator sensor

“…3f). 20,[32][33][34][35][36][37] Then the I-TENGs were placed in a heating furnace and heated at different temperatures for various times. These sensors were then removed and tested at room temperature.…”

A Review on Epidermal Nanogenerators: Recent Progress of the Future Self‐Powered Skins

“…Stretchable and/or shape adaptable 41 [53,79,126,130,158, Ultrathin d) 5 [183,190,205,210,213] Transparent 9 [130,158,182,187,194,196,203,206,213] Sweat permeable 1 [213] Wireless connected 5 [208,[214][215][216][217] Low-cost 11 [179,183,188,190,191,198,199,204,211,214,218] Facile manufacturing 6 [179,183,184,188,199,214] Biocompatible 4 [53,79,190,213] Metal-free 1 [219] Humidity resistive 2 [181,220] Self-healable 5…”