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Recyclable and biodegradable microelectronics, i.e., “green” electronics, are emerging as a viable solution to the global challenge of electronic waste. Specifically, flexible circuit boards represent a prime target for materials development and increasing the utility of green electronics in biomedical applications. Circuit board substrates and packaging are good dielectrics, mechanically and thermally robust, and are compatible with microfabrication processes. Poly(octamethylene maleate (anhydride) citrate) (POMaC) – a citric acid-based elastomer with tunable degradation and mechanical properties – presents a promising alternative for circuit board substrates and packaging. Here, we report the characterization of Elastomeric Circuit Boards (ECBs). Synthesis and processing conditions were optimized to achieve desired degradation and mechanical properties for production of stretchable circuits. ECB traces were characterized and exhibited sheet resistance of 0.599 Ω cm⁻², crosstalk distance of <0.6 mm, and exhibited stable 0% strain resistances after 1000 strain cycles to 20%. Fabrication of single layer and encapsulated ECBs was demonstrated.

This study presents a set of strategies for producing potent antibacterial fabrics by functionalizing nonwoven fabrics (NWFs) with antimicrobial peptides and polymers (AMPs). The incorporation of AMPs is initially optimized on 2D substrates by evaluating conjugation on a poly(maleic anhydride) copolymer coating versus adsorption on polycationic/anionic films and microgels. The evaluation of the resulting surfaces againstS. aureusandE. colihighlights the superior antibacterial activity of poly‐ionic films loaded with daptomycin and polymyxin B as well as microgels featuring controlled release of bacitracin and polymyxin B. These formulations are translated onto spun‐bond polypropylene and poly(ethylene terephthalate) NWFs. The poly‐ionic coatings are either covalently anchored or physically adsorbed onto the surface of the fibers, while the microgels and antibacterial polymers are adsorbed and photo‐crosslinked thereon using a ultraviolet (UV)‐crosslinkable benzophenone‐based polymer. Selected formulations loaded with bacitracin and polymyxin B afford a 10⁵‐fold reduction ofStaphylococcus aureus (S. aureus)andEscherichia coli (E. coli)in artificial sweat, respectively, on par with commercial antibacterial NWFs. The proposed antibacterial fabric, however, outperforms its commercial counterparts in terms of biocompatibility, showing virtually no adverse effect on human epidermal keratinocytes. Collectively, these results demonstrate affordable and scalable routes for developing antimicrobial NWFs that efficiently eliminate resilient pathogenic bacteria.

This study presents a comprehensive survey of microgel‐coated materials and their functional behavior, describing the complex interplay between the physicochemical and mechanical properties of the microgels and the chemical and morphological features of substrates. The cited literature is articulated in four main sections: i) properties of 2D and 3D substrates, ii) synthesis, modification, and characterization of the microgels, iii) deposition techniques and surface patterning, and iv) application of microgel‐coated surfaces focusing on separations, sensing, and biomedical applications. Each section discusses – by way of principles and examples – how the various design parameters work in concert to deliver functionality to the composite systems. The case studies presented herein are viewed through a multi‐scale lens. At the molecular level, the surface chemistry and the monomer make‐up of the microgels endow responsiveness to environmental and artificial physical and chemical cues. At the micro‐scale, the response effects shifts in size, mechanical, and optical properties, and affinity towards species in the surrounding liquid medium, ranging from small molecules to cells. These phenomena culminate at the macro‐scale in measurable, reversible, and reproducible effects, aiming in a myriad of directions, from lab‐scale to industrial applications.