Highly conductive and elastic nanomembrane for skin electronics

Abstract

Skin electronics require stretchable conductors that satisfy metallike conductivity, high stretchability, ultrathin thickness, and facile patternability, but achieving these characteristics simultaneously is challenging. We present a float assembly method to fabricate a nanomembrane that meets all these requirements. The method enables a compact assembly of nanomaterials at the water–oil interface and their partial embedment in an ultrathin elastomer membrane, which can distribute the applied strain in the elastomer membrane and thus lead to a high elasticity even with the high loading of the nanomaterials. Furthermore, the structure allows cold welding and bilayer stacking, resulting in high conductivity. These properties are preserved even after high-resolution patterning by using photolithography. A multifunctional epidermal sensor array can be fabricated with the patterned nanomembranes.

Flexible Electronics and Devices as Human–Machine Interfaces for Medical Robotics

“…For both of these examples, interface problems mainly arise in heterogeneous integration of different materials, such as for material bonding and embedding, which can be addressed by micromechanics and chemical bonding links. [ 606 ] Specifically for human–device interfaces, there are additionally macro interface problems one must consider. For example, the large conformal attachment of prosthetic skin, [ 149 ] sweat trap between the wearable sensor and the skin, [ 75 ] and fixation of neural implants.…”

Omnidirectional printing of elastic conductors for 3D-structured stretchable electronics

“…Skin electronics augment the capability of shareable signals from personal and metabolic activities over communication networks by blurring the physical discontinuity between electronic devices and human skin [1][2][3][4] . With their unique mechanical characteristics, such as lightweight design, softness, and stretchability, skin electronics can be functionalized on various body parts 5,6 and even brains 7 and hearts 8 in the forms of biosensors, processors, and displays.…”

Ultra-thin foldable transparent electrodes composed of stacked silver nanowires embedded in polydimethylsiloxane

“…In particular, the recent launch of foldable display terminals has inspired and given more attention to development of truly foldable and rolled display devices. For these devices, preparation and performance optimization of transparent electrodes that can be flexibly formed are important steps [1]. The quality of the transparent electrode materials is the key factor to determine the performance of electron transport and collection in various photoelectric devices, including wearable electronics, light-emitting diodes, solar cells, touch screens, electronic paper and electromagnetic interference shields [2][3][4][5].…”

“…However, the brittleness of ITO and the requirements of high-temperature annealing and a vacuum deposition environment are not compatible with potential flexible processing technology [6][7][8][9]. To solve this problem, several alternative materials have been developed by different research groups, such as graphene [10][11][12], carbon nanotubes [13][14][15], conductive polymers [16][17][18] and metal nanowires [1,[19][20][21]. Among these alternative materials that can be flexibly processed, metal nanowire (NW) structures, especially silver NW (AgNW) networks, have high optical transmittance and good conductivity properties.…”