Reversible photo-patterning of soft conductive materials via spatially-defined supramolecular assembly

Abstract

A strategy for reversible patterning of soft conductive materials is described, based upon a combination of peptide-based block copolymer hydrogelators and photo-thermally-active carbon nanotubes. This composite displays photo-responsive gelation at application-relevant timescales (< 10 s), allowing for rapid and spatially-defined construction of conductive patterns (> 100 S/m), which, additionally, hold the capability to revert to sol upon sonication for reprocessing.

Smart Hydrogels Meet Carbon Nanomaterials for New Frontiers in Medicine

“…An alanine-based amphiphile hydrogelator was used with redox-active viologen to obtain a hydrogel, and addition of CNTs rendered the system quasi redox reversible for applications in bioelectronics [ 155 ]. CNTs were also used to impart photo-responsiveness to a hydrogel that already displayed gel-to-sol transition upon ultrasonication, thus providing a multi-responsive system envisaged for bioelectronics [ 158 ]. A poly(N-isopropylacrylamide) thermo- and pH-responsive hydrogel embedding CNTs provided an artificial muscle which, upon inclusion of the glucose oxidase enzyme in the system, displayed responsiveness to glucose as a model biomolecule [ 147 ].…”

Flexible and Stretchable Elastomer Composites Based on Lightweight Liquid Metal Foam Spheres with Pod-like Contacts

“…Strain- and temperature-sensitive soft composites have been extensively developed in recent years because of their broad applications for emerging wearable electronics or flexible robotics. − These conductive composites with flexible/stretchable mechanical and electrical properties have attracted great interest due to their high sensitivity and good deformability. , Traditional soft conductive composites usually combine flexible matrix, such as polyurethane (PU) and polydimethylsiloxane (PDMS), , with conductive fillers, such as metallic microparticles, , carbon nanotubes, graphene, etc. In order to achieve highly conductive, sensitive, and flexible features, the soft composites can also be prepared by printing or transferring conductive patterns on a flexible matrix to form conductive laminated structures. , However, there will be a significant compliance mismatch between the rigid conductive fillers and the flexible elastomer matrix, increasing the risk of composite failure and reducing the extensibility, which not only limits the flexibility of composites but also affects the conductivity of flexible sensors under external loadings.…”

“…1−4 These conductive composites with flexible/ stretchable mechanical and electrical properties have attracted great interest due to their high sensitivity and good deformability. 5,6 Traditional soft conductive composites usually combine flexible matrix, such as polyurethane (PU) 7 and polydimethylsiloxane (PDMS), 8,9 with conductive fillers, such as metallic microparticles, 10,11 carbon nanotubes, 12 graphene, etc. 13 In order to achieve highly conductive, sensitive, and flexible features, the soft composites can also be prepared by printing or transferring conductive patterns on a flexible matrix to form conductive laminated structures.…”

Modularly Constructed Polyhedral Oligomeric Silsesquioxane-Based Giant Molecules for Unconventional Nanostructure Fabrication

“…Achieving materials with desired properties and functionalities via reverse thinking and designing has been demonstrated as one of the most promising ways in self-assembly (“bottom-up”) approaches. In the past two decades, different functionalized nanoscale building blocks have been used to achieve various interesting nanostructures and properties in soft matters. − Specifically, Frank–Kasper (F–K) phases, which originally appeared in metal-alloys with specifically required spherical motifs, , are receiving researchers’ attention since they have been observed in soft materials, such as supramolecular dendrimers, − self-organizable dendronized polymers, − block copolymers, − surfactants, − and giant molecules. − For example, in 1997, the first thermotropic A15 ( Pm 3̅ n ) phase in soft matter was discovered in dendrimers by Percec et al Since then, a number of dendrimers were found to assemble into the A15 ( Pm 3̅ n ) phase, − σ ( P 4 2 /mnm ) phase, and quasicrystal phase , together with the traditional phases, providing a “nanoperiodic table” of supramolecular structures. ,, Bates et al discovered the F–K σ ( P 4 2 /mnm ) phase, C14 ( P 6 3 /mmc ) phase, and C15 ( Fd 3̅) phase in sphere-forming block copolymer melts. − Mahanthappa et al found F–K phases formation in surfactant micelles. − In the meantime, some simulation and theoretical works about F–K phases have been carried out. − For example, Kamien et al investigated the theory of F–K phase formation using a packing model of a hard core and soft corona system. , Goddard et al conducted molecular dynamic simulation of supramolecular dendr...…”