Polymer Chemistries Underpinning Materials for Skin-Inspired Electronics

Abstract

Polymers play a multifaceted role in driving the progress of research in skin-inspired electronicsan emerging technology with promising implications in human health, the environment, and information infrastructure. Polymers may function as the substrate, encapsulant, adhesive, matrix, or active material. A vast chemical design space to molecularly engineer polymer structures allows physical properties and functionalities to be readily tuned. Diverse opportunities exist to exploit the recent synthetic advances and methodologies in polymer chemistry to advance skin-inspired electronics. This Perspective highlights chemistries underpinning polymeric materials currently employed in skin-inspired electronics and provides an outlook on chemistries that are potentially exciting to utilize. The aim of this Perspective is to concurrently expose device engineers to the chemical diversity of polymers and enthuse chemists to evaluate their synthetic expertise for potential skin-inspired electronics. Ultimately, the collective collaborations between chemists and engineers are critical to further advance the field of electronic skin.

Soft mixed ionic–electronic conductive electrodes for noninvasive stimulation

“…The electrical conductivity versus loading of SWNTs in the NBR composite is shown in (Figure ). It is well known that adding a conductive additive (such as SWNTs) to a host material increases it electrical conductivity . As the loading of filler increases, a percolating network of conducting particles is achieved and the conductivity begins to increase; this percolation threshold is a function of the particle aspect ratio and dispersion in the matric.…”

“…The demand for noninvasive, stimulating, and recording wearable electronic devices is expanding, with broad applications including electrotherapeutics, biosensing, remote healthcare/wellness monitoring, wound healing, human machine interface systems, and sports medicine . These systems all require electrodes to facilitate charge transfer across the interface between the device and the skin.…”

“…On‐going research efforts seek to address this issue through improvements in the electrodes and/or the coupling with the skin. Flexible electrodes, which can adhere, conform, and stretch along with the skin, offer a means to bypass challenges of rigid electrodes . By matching the mechanical and thermal properties of the skin improved interfacial charge transfer may be achieved.…”

A Skin‐Inspired Substrate with Spaghetti‐Like Multi‐Nanofiber Network of Stiff and Elastic Components for Stretchable Electronics

“…[ 1–5 ] In such systems, the mechanical stretchability and motion‐immune stability of skin mountable devices is essential for many applications including human motion and activity monitors, [ 6–9 ] human–machine interfaces, [ 10 ] observing virtual reality, [ 11 ] physical rehabilitation, [ 12,13 ] energy harvesting, [ 14 ] and stretchable epidermal electronics. [ 15–17 ] User comfort, stretchability, high conformality, mechanical durability, and motion‐immune device stability are essential features. [ 3,18,13 ] Tunability of mechanical modulus and design freedom with respect to shape can be used to avoid a potential mismatch between rigid electronics and soft tissues, where incompatibility leads to a degradation in device performance, discomfort, and delamination.…”

Binding Capability and Non–biofouling Efficacy of Poly[2‐(methacryloyloxy)ethyl‐4‐pentynoate‐co‐oligo(ethylene Glycol) Methacrylate] Films on Gold Surfaces

“…Polymeric thin films are playing an increasingly important role in the elucidation of biological phenomena, such as cell–cell interactions and are also important constituents of various technologies, including coatings, lithography, adhesives, analytical detection, drug delivery, sensors, and energy conversion and storage devices . For example, cell–surface engineering with polymeric thin films to form cell‐in‐shell structures has recently emerged as a promising strategy for biocatalysis, cell‐based therapies, and tissue engineering .…”