Recent advances in breathable electronics

The successful implementation of bioelectronic devices attached to living organism hinges on a number of material and device characteristics, including not only electrical and mechanical performances to gather physiological signals from living organism thus enabling status monitoring, but also permeability or breathability for gas/nutrient exchange between living organisms and surroundings to ensure minimum perturbation of the intrinsic biological function. However, most bioelectronic devices built on planar polymeric substrates, such as polydimethylsiloxane (PDMS), polyurethane (PU), and polyimide (PI), lack efficient gas permeability, which may hinder the emission of volatile compounds from the surface of living organism, affecting the natural metabolism and reducing the comfort of wearing. Thus, achieving permeability or breathability in bioelectronic devices is a significant challenge. Currently, the devices made of gas-permeable materials with porous structures, that combine electronic components with daily garments, such as fibric and textile, offer exciting opportunities for breathable electronics. In this review, several types of gas-permeable materials with their synthesis and processing routes are outlines. Then, two methods for measuring water vapor transmission rate of materials are discussed in depth. Finally, recent progress in the use of gas-permeable materials for the applications of plant- and skin-attached electronics is summarized systematically.