Front Cover: The properties of elastomers are exploited to trigger wrinkling instabilities in curved shells. Each electrospun micro‐ or nanofiber consists of a soft core and a stiff outer half‐shell, which are length‐mismatched because of differential solvent de‐swelling. The fibers only wrinkle after attaining a well‐defined helical shape. A simple analytical model is proposed to find the curvature and wrinkle wavelength. Further details can be found in the article by A. C. Trindade, J. P. Canejo, P. I. C. Teixeira, P. Patrício,* and M. H. Godinho* on page 1618.

Stimulus‐sensing biohybrid materials have attracted significant interest as smart materials with applications especially in the biomedical field. Such materials harnessing unique properties of chemical and biological polymers are engineered to translate molecular stimuli into precisely defined mechanical material properties. This article gives an overview of how biological polymers can be used to control material properties and on their applications.

Ring‐opening metathesis polymerization (ROMP) of acene‐annulated norbornadienes leads to acene comprising polynorbornadienes. A pentacene‐containing polymer is successfully integrated into an organic field‐effect transistor (OFET) and a tetracene‐containing polymer is integrated into an organic light‐emitting diode (OLED). The monomers result from the Diels–Alder reactions of the corresponding arynes and cyclopentadiene.

This work exploits the properties of elastomers to trigger wrinkling instabilities in curved shells. Each electrospun micro‐ or nano‐fibre consists of a soft core and a stiff outer half‐shell, which are length‐mismatched because of differential solvent de‐swelling. The fibres only wrinkle after attaining a well‐defined helical shape. A simple analytical model is proposed to find the curvature and wrinkle wavelength.

An indacenodithiophene‐based conjugated polymer presenting pendant n‐hexylthiophene as conjugated side chains is synthesized. A deep HOMO energy level of –5.46 eV is obtained due to conformational twisting of the polymer main chain, induced by the side chain conjugated units. An open circuit voltage of 0.947 V and PCE up to 4.5% can be achieved.

A new class of stable complex colloidal polymer clusters with a colloid within a colloidal particle morphology is synthesized via redox‐initiated heterophase polymerization, in which ceric ion and β‐cyclodextrin (β‐CD) as redox initiators are used to initiate the polymerization of N‐isopropyl acrylamide (NIPAM) and styrene in sequence.

Branched ring‐opening metathesis polymerization (ROMP)‐polymer architecture is successfully constructed employing AB_n‐type macromonomer that carries several thiol groups along the polymer chain and one acrylate group at the chain end. A thiol‐Michael addition click reaction between these functional groups yields long‐chain highly branched polymer. The coating of gold nanoparticles is shown as one interesting application of such functionalized metathesis polymers.

The incorporation of increasing loading fraction of PS‐coated gold nanoparticles into cylinder‐forming block copolymer films induces a facile vertical to random‐in‐plane horizontal morphology transition under dynamic thermal gradient field. Soft‐shear could further align the hybrid nanostructures.

A new polymer, functionalized with pendant oligoaniline groups, that exhibits the unique multi‐stimuli‐responsive fluorescence switching properties by redox, pH, and electrical potential stimuli is reported. In this system, the oligoaniline segments are used as fluorophore and regulatory units simultaneously. The fluorescence switching operation shows reasonable reversibility and reproducibility when subjected to multiple stimuli, which demonstrate the availability of controlling/adjusting the fluorescence of polymer through a variety of inputs.

A general picture of structural transitions and relaxation processes in gradient copolymer micelles is presented, which is made up of a unimers to micelles transition, a star‐like micelles to crew‐cut micelles transition, and a morphological transition.