Stencil Printing of Liquid Metal upon Electrospun Nanofibers Enables High-Performance Flexible Electronics

Abstract

Flexible electronics as an emerging technology has demonstrated potential for applications in various fields. With the advent of the Internet of Things era, countless flexible electronic systems need to be developed and deployed. However, materials and fabrication technologies are the key factors restricting the development and commercialization of flexible electronics. Here we report a simple, fast, and green flexible electronics preparation technology. The stencil printing method is adopted to pattern liquid metal on the thermoplastic polyurethane membrane prepared by electrospinning. Besides, with layer-by-layer assembly, flexible circuits, resistors, capacitors, inductors, and their composite devices can be prepared parametrically. Furthermore, these devices have good stretchability, air permeability, and stability, while they are multilayered and reconfigurable. As proof, this strategy is used to fabricate flexible displays, flexible sensors, and flexible filters. Finally, flexible electronic devices are also recycled and reconfigured.

Stretchable, breathable, and highly sensitive capacitive and self-powered electronic skin based on core–shell nanofibers

“…The TPU matrix comprises a solid ellipsoid and soft segments, which leads to visco-poroelastic characteristics when TPU is mixed with ionic liquids. 37 In recent times, liquid metal (LM) has emerged as a new generation of electronic materials, 38,39 which is extensively utilized in flexible electronics due to its great electrical conductivity, good environmental stability, and fluidity. 40 The proposed sensor is made layer by layer; both bottom and top layers are the TPU nanofibrous mat used as the supporting device, LM is printed on the bottom layer, and core-shell dielectric nanostructures (detailed in the Experimental section).…”

High Sensitivity, Broad Working Range, Comfortable, and Biofriendly Wearable Strain Sensor for Electronic Skin

“…TPU has excellent comprehensive properties such as high elasticity, high toughness, and excellent biocompatibility, and is widely used in medical and wearable devices. [5,38] In comparison with other film-forming processes such as dip-coating, spin-coating, and vacuum filtration, the film prepared by the electrospinning process has excellent air permeability and better hydrophobicity (the static contact angle of the electrospinning film is 125°), and is more suitable for wearable devices. [39,40] The CI mainly composed of CNTs and graphene not only has the stability and printability of ordinary inks but also has excellent conductivity.…”

“…[1][2][3] This is particularly true for resistive-type strain sensors, which are designed to detect a broad variety of subtle or large deformations. They are considered to be indispensable components in novel applications such as electronic skin, [4][5][6] soft robots, [7][8][9] human health monitoring, [10][11][12] and humancomputer interaction owing to their versatility. [13,14] In previous studies, the sensitivity, responsiveness, and linearity of sensors have been continuously optimized.…”

Graphene-Based Polymer Composites for Flexible Electronic Applications

“…Moreover, the manufacture of conductive materials in a quick, economic, and sustainable way is one of the main prerequisites for flexible electronics [ 15 ]. In this regard, a simple, fast, and sustainable flexible electronics preparation technology was reported by Wang et al [ 18 ] to address the key restraints of materials and fabrication techniques. They prepared a thermoplastic polyurethane (TPU) membrane by electrospinning, which was used as substrate in a sandwich structure, assembled layer by layer, and each layer was composed of a TPU membrane, and a liquid metal printed on it.…”