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Abstract Paper has remained the world's most‐widely accessible information medium even as sustainable and reusable paper replacements have attracted increasing attention. Here, an ink‐free rewritable paper concept is developed that combines recent developments in photonic crystals, shape memory polymers, and electroactive polymers in a nanocomposite that matches the benefits of paper as a zero‐energy, long‐term data storage medium, but provides the additional advantage of rewritability. The rewritable paper consists of a ferroferric oxide‐carbon (Fe₃O₄@C) core–shell nanoparticle (NP)‐based photonic crystal embedded in a bistable electroactive polymer (BSEP). Electrical actuation induces large deformation in the z‐axis of the nanocomposite, creating distinct color change in the actuated area. This nanocomposite stores high fidelity color images without inks, the images remain stable after more than a year of storage in ambient conditions, and the stored images can then be rewritten over 500 times without degrading. A seven‐segment numerical display is also demonstrated. 

The development of intrinsically stretchable electronics poses great challenges in synthesizing elastomeric conductors, semiconductors and dielectric materials. While a wide range of approaches, from special macrostructural engineering to molecular synthesis, have been employed to afford stretchable devices, this review surveys recent advancements in employing various morphological and nanostructural control methods to impart mechanical flexibility and/or to enhance electrical properties. The focus will be on (1) embedding percolation networks of one-dimensional conductive materials such as metallic nanowires and carbon nanotubes in an elastomer matrix to accommodate large external deformation without imposing a large strain along the one-dimensional materials, (2) design strategies to achieve intrinsically stretchable semiconductor materials that include direct blending of semiconductors with elastomers and synthesizing semiconductor polymers with appropriate side chains, backbones, cross-linking networks, and flexible blocks, and (3) employing interpenetrating polymer networks, bottlebrush structures and introducing inclusions in stretchable polymeric dielectric materials to improve electrical performance. Moreover, intrinsically stretchable electronic devices based on these materials, such as stretchable sensors, heaters, artificial muscles, optoelectronic devices, transistors and soft humanoid robots, will also be described. Limitations of these approaches and measures to overcome them will also be discussed. 

Poly( l -lactide) (PLA) is a bioderived and biodegradable polymer that has limited applications due to its hard and brittle nature. Incorporation of 1,3-trimethylene carbonate into PLA, in a block copolymer fashion, improves the mechanical properties, while retaining the biodegradability of the polymer, and broadens its range of applications. However, the preparation of 1,3-trimethylene carbonate (TMC)/ l -lactide (LA) copolymers beyond diblock and triblock structures has not been reported, with explanations focusing mostly on thermodynamic reasons that impede the copolymerization of TMC after lactide. We discuss the preparation of multiblock copolymers via the ring opening polymerization (ROP) of LA and TMC, in a step-wise addition, by a ferrocene-chelating heteroscorpionate zinc complex, {[fc(PPh 2 )(BH[(3,5-Me) 2 pz] 2 )]Zn(μ-OCH 2 Ph)} 2 ([(fc P,B )Zn(μ-OCH 2 Ph)] 2 , fc = 1,1′-ferrocenediyl, pz = pyrazole). The synthesis of up to pentablock copolymers, from various combinations of LA and TMC, was accomplished and the physical, thermal, and mechanical properties of the resulting copolymers evaluated. 

A thin-film field-effect transistor (TFT) is a three-terminal device comprising source, drain, and gate electrodes, a dielectric layer, a semiconductor layer, and a substrate. The TFT is a fundamental building component in a variety of electronic devices. Developing an intrinsically stretchable TFT entails availability and usage of a functional material with elastomeric deformability in response to an externally applied stress. This represents a major materials challenge. In this article, we survey strategies to synthesize these elastomeric functional materials, and how these materials are assembled to fabricate intrinsically stretchable TFT devices. Developing solution-based printing technology to assemble intrinsically stretchable TFTs is considered a prospective strategy for wearable electronics for industrial adaptation in the near future.