Highly Efficient and Water‐Insensitive Self‐Healing Elastomer for Wet and Underwater Electronics

Abstract

Integrating self-healing capabilities into soft electronic devices increases their durability and long-term reliability. Although some advances have been made, the use of self-healing electronics in wet and/or (under)water environments has proven to be quite challenging, and has not yet been fully realized. Herein, a new highly water insensitive self-healing elastomer with high stretchability and mechanical strength that can reach 1100% and ≈6.5 MPa, respectively, is reported. The elastomer exhibits a high (>80%) self-healing efficiency (after ≈ 24 h) in high humidity and/or different (under)water conditions without the assistance of an external physical and/or chemical triggers. Soft electronic devices made from this elastomer are shown to be highly robust and able to recover their electrical properties after damages in both ambient and aqueous conditions. Moreover, once operated in extreme wet or underwater conditions (e.g., salty sea water), the self-healing capability leads to the elimination of significant electrical leakage that would be caused by structural damages. This highly efficient self-healing elastomer can help extend the use of soft electronics outside of the laboratory and allow a wide variety of wet and submarine applications.

Multiple H‐Bonding Chain Extender‐Based Ultrastiff Thermoplastic Polyurethanes with Autonomous Self‐Healability, Solvent‐Free Adhesiveness, and AIE Fluorescence

“…The stretching vibration region of CO groups is split into two peaks at 1693 and 1647 cm −1 , which are ascribed to free CO groups and hydrogen‐bonded CO groups, respectively. [ 14c,15b ] The characteristic peak of NCO does not appear at 2260–2280 cm −1 in the spectra, proving that NCO of IPDI completely reacted with OH to form urethane. The 1 H NMR result also confirms the structures of the prepolymer (PUIP) and as‐prepared PU (PUIP‐NAGA) (Figure S4, Supporting Information).…”

“…A similar phenomenon has been reported in the previous literature. [ 14b ] The PUIP‐NAGA1.6 can be stretched to over 22 times (2200%) its original length without rupture at a loading rate of 50 mm min −1 , and the tensile strength and Young's modulus are 10 kPa, and 1.31 MPa, respectively. With increasing the OHNAGAOH content, the number of hard segments is accordingly increased, which act as H‐bonding cross‐linkages.…”

“…[ 13 ] Thus far, several design strategies have been developed to construct multiphase‐separated healable supramolecular PU with tunable soft segments and hard segments by combining the weak H‐bonds in the urethane with other non‐covalent interactions in main chain. [ 14 ] Nevertheless, these approaches are mainly based on the non‐covalent interactions in the main chains and the special designs of either soft segment or hard segment. Besides, due to the constrained mobility of backbone, input of external energy (either heat or light) [ 15 ] or addition of metal ions [ 16 ] is required to achieve self‐healing.…”

A Multifunctional Electronic Skin Empowered with Damage Mapping and Autonomic Acceleration of Self‐Healing in Designated Locations

“…The basic matrix that composes all three layers of the reported e‐skin relies on the dynamic self‐healing polymer, PBPUU ( Figure A,B), which was previously developed by our group. [ 11 ] This polymer was shown to have a tensile strength of ≈6.5 MPa besides its efficient self‐healing capability in a wide variety of underwater conditions including tap water, sea water, and water with different pH values (Figure 2C). It was also able to eliminate any electrical leakages caused by underwater damages.…”

Mechanically Stable Dynamic Urea Bond‐Based Crosslinked Polymer Blend with Tunable Self‐Healable and Physical Properties

“…The self‐healing mechanism of self‐healing polymers is mostly based on the dynamically reversible bond (e.g., hydrogen bonding, [ 4–7 ] π–π interactions, [ 8 ] metal–ligand interactions, [ 9,10 ] guest–host interactions, [ 11 ] Diels–Alder chemistry, [ 12,13 ] boronic ester, [ 14,15 ] diselenide, [ 16 ] diarylbibenzofuranone, [ 17 ] disulfide, [ 18,19 ] and alkoxyamine [ 20 ] ), shape memory effect‐assisted self‐healing, [ 21,22 ] and the enhanced movement of polymeric chain. Of note, the polymeric chain mobility is a key factor to facilitate dynamic bond reversibility and self‐healing.…”