Superflexible Artificial Soft Wood

Abstract

Soft woods have attracted enormous interest due to their anisotropic cellular microstructure and unique flexibility. The conventional wood‐like materials are usually subject to the conflict between the superflexibility and robustness. Inspired by the synergistic compositions of soft suberin and rigid lignin of cork wood which has good flexibility and mechanical robustness, an artificial soft wood is reported by freeze‐casting the soft‐in‐rigid (rubber‐in‐resin) emulsions, where the carboxy nitrile rubber confers softness and rigid melamine resin provides stiffness. The subsequent thermal curing induces micro‐scale phase inversion and leads to a continuous soft phase strengthened by interspersed rigid ingredients. The unique configuration ensures crack resistance, structural robustness and superb flexibility, including wide‐angle bending, twisting, and stretching abilities in various directions, as well as excellent fatigue resistance and high strength, overwhelming the natural soft wood and most wood‐inspired materials. This superflexible artificial soft wood represents a promising substrate for bending‐insensitive stress sensors.

A reflection on ‘A shape-memory scaffold for macroscale assembly of functional nanoscale building blocks’

“…Over the last ten years, a wave of related research efforts has been inspired by the proposed practical assembly strategy. 6–9,14–17 Some have focused on further expanding the compositions and types of scaffolds to build multifunctional macroscopic assemblies (Fig. 1).…”

“…9 Recently, Yu and co-workers successfully integrated a long-chain fatty acid macromolecule into the rigid one-dimensional pore walls of a resin wood-like scaffold fabricated by unidirectional freeze casting, which endows the artificial wood with super-flexibility. 14…”

Renewable biomass-based aerogels: from structural design to functional regulation

“…A “mortar–brick” aerogel can be fabricated by adding additional materials into the orientate channel of plant-based aerogels. 334 For example, Yan et al integrated a large number of silica nanoparticles into the pores of wood aerogel by in situ polycondensation to produce wood/silica aerogels with “mortar–brick” structures (Fig. 20a).…”

Transforming wastes into functional materials: natural cork-based physical structural components and polymers

“…By amalgamating isolated cork components with advanced nanomaterials, the trajectory of wearable technology can be propelled towards the realization of more flexible and high-performance electronic devices, thereby harnessing the full potential of cork's unique chemical composition and multilayered cell wall structure in informing the biomimetic design of functional materials. 166…”