Gas‐Permeable, Multifunctional On‐Skin Electronics Based on Laser‐Induced Porous Graphene and Sugar‐Templated Elastomer Sponges

Abstract

closely relevant to normal bodily functions as well as clinical cues of the progression of various diseases. Thus, their continuous and real-time acquisition with soft on-skin electronics, in a manner that does not disrupt our routine daily activities, will be useful for medical diagnostics, fitness tracking, human-machine interface, athletic training, and many others. During the past decade, soft on-skin electronics have been achieved by employing flexible and stretchable forms of inorganic electronic materials, [1][2][3] intrinsically soft organic electronic materials, [6][7][8][9] or emerging nanomaterials [10][11][12][13] as device components and using elastomers or plastics as substrates. However, one critical scientific challenge is that most materials used for on-skin electronics have limited gas permeability, which blocks sweat gland and constrains perspiration evaporation, resulting in adverse physiological and psychological effects, such as rashes, stuffiness, and/or other inflammatory skin responses, limiting their longterm feasibility. [10] In addition, the device fabrication process of on-skin electronics usually involves e-beam or photolithography, thin-film deposition, etching, and/or other complicated procedures, which are costly and time-consuming, constraining their practical applications.Great progress has been recently achieved to address the aforementioned two challenges. For example, free-standing gold nanomesh conductors were used to develop on-skin electronics with high gas permeability, which can significantly suppress the risks of skin inflammation, but are limited to complex fabrication processes such as electrospinning and vacuum deposition. [10] In another study, a "cut-and-paste" manufacturing method was developed to offer a simple way of fabricating multiparametric on-skin electronic systems. [17] However, the materials used for device fabrication, such as gold and aluminum, have limited gas permeability. Therefore, it is highly desirable to develop a simple and effective approach of making on-skin electronics using highly gas-permeable materials.Introducing porous structures into existing functional materials is a powerful way to tailor their gas permeability as well Soft on-skin electronics have broad applications in human healthcare, humanmachine interface, robotics, and others. However, most current on-skin electronic devices are made of materials with limited gas permeability, which constrain perspiration evaporation, resulting in adverse physiological and psychological effects, limiting their long-term feasibility. In addition, the device fabrication process usually involves e-beam or photolithography, thin-film deposition, etching, and/or other complicated procedures, which are costly and time-consuming, constraining their practical applications. Here, a simple, general, and effective approach for making multifunctional on-skin electronics using porous materials with high-gas permeability, consisting of laserpatterned porous graphene as the sensing components and sugar-templa...

A Highly Stretchable Microsupercapacitor Using Laser‐Induced Graphene/NiO/Co3O4 Electrodes on a Biodegradable Waterborne Polyurethane Substrate

“…This gradient structure is beneficial to both electrochemical properties and the transfer process because the outer hydrophilic multilayer surface is capable of being impregnated with electrolyte as well as with WPU and because the inner structure is expected to maintain a porous structure in favor of enormous charge accumulation. [27] After the peeling step, some smooth residual fragments without redundant WPU are clearly observed in Figure S4 (Supporting Information). Additionally, the cross-section morphology in the middle and bottom are shown in Figure 1g,h.…”

“…After 1000 cycles of stretching and releasing at 100%, there is only slight deformation with some structure distortion shown in the morphology (Figure 5g). [27] Furthermore, the stretchable WPU "bridges" are studded with visible graphene fragments, thereby forming a temporary conducting path during the dynamic stretching process. [27] Furthermore, the stretchable WPU "bridges" are studded with visible graphene fragments, thereby forming a temporary conducting path during the dynamic stretching process.…”

“…[27][28][29][30] For example, Lamberti et al demonstrated PDMS based stretchable MSCs with an areal capacitance of 650 µF cm −2 that showed an 84% capacitance retention after 1000 cycles of stretching. [27][28][29][30] For example, Lamberti et al demonstrated PDMS based stretchable MSCs with an areal capacitance of 650 µF cm −2 that showed an 84% capacitance retention after 1000 cycles of stretching.…”

Semi‐Liquid‐Metal‐(Ni‐EGaIn)‐Based Ultraconformable Electronic Tattoo

“…Nonstretchable inorganic electronic materials, such as gold, copper, and silver, change the geometric structure to fit the stretched substrates. With low-cost fabrication methods, such as direct printing [20,25] and transfer printing, [21] these materials have been highly successfully used to fabricate stretchable circuits, [26] sensing arrays, [27] and near field communication antennae. Alternatively, other inorganic electronic materials, such as nanoparticles [19][20][21] and carbon nanotubes, [22][23][24] are deposited on elastomer substrates to form a thin nanopath that can be extended when the substrates are stretched.…”

“…Alternatively, other inorganic electronic materials, such as nanoparticles [19][20][21] and carbon nanotubes, [22][23][24] are deposited on elastomer substrates to form a thin nanopath that can be extended when the substrates are stretched. With low-cost fabrication methods, such as direct printing [20,25] and transfer printing, [21] these materials have been highly successfully used to fabricate stretchable circuits, [26] sensing arrays, [27] and near field communication antennae. [21] Meanwhile, organic electronic materials, such as conductive small molecules and polymers and carbon-based conductive materials, [28] have good stretchability and their special chemical groups provide good conductivity.…”