Super Tough and Self-Healable Poly(dimethylsiloxane) Elastomer via Hydrogen Bonding Association and Its Applications as Triboelectric Nanogenerators

Abstract

Poly­(dimethylsiloxane) (PDMS) as one of the electron-drawing materials has been widely used in triboelectric nanogenerators (TENG), which is expected to generate electron through friction and required to endure dynamic loads. However, the nature of the siloxane bond and the low interchain interaction between the methyl side groups result in low fracture energy in PDMS elastomers. Here, a strategy that combined the advantages of the dynamic of hierarchical hydrogen bonding and phase-separation-like structure was adopted to improve the toughness of PDMS elastomers. By varying both stronger and weaker hydrogen bonding within the PDMS network, a series of super tough (up to 24,000 J/m2), notch-insensitive, transparent, and autonomous self-healable elastomers were achieved. In addition, a hydrophilic polymeric material (PDMAS-U10) was synthesized as the conductive layer. A transparent TENG was fabricated by sandwiching the PDMAS-U10 between two pieces of the PDMS elastomer. Despite its hydrophilic nature, PDMAS-U10 exhibit strong adhesion interaction with hydrophobic PDMS elastomers. As such, a tough (16,500 J/m2), self-healable (efficiency ∼97%), and transparent triboelectric nanogenerator was constructed. A self-powered system employing the TENG is also demonstrated in this work.

Dynamic Polymer Networks: A New Avenue towards Sustainable and Advanced Soft Machines

“…[45] Thet riboelectric layer was synthesised by cross-linking amine functional [39];b)V oc output of asupramolecular TENG under strain (left) and before and after self-healing( right), adapted with permission from Ref. [42];c)demonstration of TENG devices based on an associative DPN being built up from identical TENG "bricks", adapted with permission from Ref. [43].…”

“…Chen et al. developed a high‐toughness PDMS electrification layer that was cross‐linked through hydrogen bonding between urea and urethane groups (A x –H 10− x ) [42] . The A x –H 10− x network was able to bond strongly with the UPy groups in the electrode layer, allowing for operation at 16 000 cycles of repeated contact‐separation with no loss in V oc output (approx.…”

Bioimpedance Sensors: A Tutorial

“…Some common examples have been compared in [146]. Such elastomers can be modified or synthesized to demonstrate self-healing properties or good skin adhesion [147], [148]. Printing methods commonly used include inkjet [149], [150], screen [151], stencil, molding [140], [141] and extrusion-based (that we have been exploring in our Centre due to their simplicity) [152]- [154] and other 3D printing technologies [155], [156], as well as roll-to-roll contact printing approaches, such as gravure, flexographic printing [11] and transfer printing methods.…”

Dynamic Polymer Networks: A New Avenue towards Sustainable and Advanced Soft Machines

“…Thehigh interfacial adhesion in multi-layered devices that are subject to movement and friction, such as TENGs,i s critical for their long term performance.C hen et al developed ah igh-toughness PDMS electrification layer that was cross-linked through hydrogen bonding between urea and urethane groups (A x -H 10Àx ). [42] TheA x -H 10Àx network was able to bond strongly with the UPy groups in the electrode layer, allowing for operation at 16 000 cycles of repeated contact-separation with no loss in V oc output (approx. 12 V).…”

“…Ahigh transparencyfor the TENG was [39];b)V oc output of asupramolecular TENG under strain (left) and before and after self-healing( right), adapted with permission from Ref. [42];c)demonstration of TENG devices based on an associative DPN being built up from identical TENG "bricks", adapted with permission from Ref. [43].…”