Low‐Resistant Electrical and Robust Mechanical Contacts of Self‐Attachable Flexible Transparent Electrodes with Patternable Circuits

Abstract

Flexible, transparent, conductive electrodes are key elements of emerging flexible electronic and energy devices. Such electrodes should form an intimate physical contact with various active components of flexible devices to ensure stable, low-resistant electrical contacts. However, contact formation techniques are based largely on conventional soldering, conductive pastes, mechanical clamping, and thin film deposition. These generally result in damaged, contaminated, bulky, and uncontrollable contact interfaces. A self-attachable, flexible, transparent, and conductive electrode that is based on a distinctive design of regular grid patterns into which bioinspired adhesive architectures and percolating Ag nanowires are integrated is proposed. Based on this integrated design, the proposed electrode forms reliable, low-resistant electrical contacts; strong mechanical adhesive contacts; and ultra-clean, damage-free contact interfaces with active device components by attaching onto the components without using additional conductive pastes, mechanical pressing, or vacuum deposition processes. The contact interfaces of the electrode and device components remain stable even when the electrode is extremely bent. Moreover, specific electronic circuits can be generated on the electrode surface by a selective deposition of Ag nanowires. This enables simple interconnections of diverse electronic components on its surface.

Applications of Bioinspired Reversible Dry and Wet Adhesives: A Review

“…However, these methods not only cause damage or injury to a substrate but also delaminate the sensors from the substrate under wet conditions (Ameri et al, 2017;Park et al, 2020). The application of bioinspired dry/wet adhesives to sensors has superior advantages compared to previous methods: (1) reversible and restorable adhesion, (2) enhanced conformality to the rough surface, and (3) versatility to diverse substrates with different surface properties (Hwang et al, 2020).…”

“…Moreover, adhesive microstructures enable wearable sensors that strongly adhere to skin, where continuous deformation and sweat may occur (Drotlef et al, 2017;Wi et al, 2017;Chun et al, 2019). In recent years, bioinspired adhesives with functional materials, such as conductive, biocompatible, and stimuli-responsive polymers or nanocomposites, have been proposed for advanced applications (Gu et al, 2018;Hwang et al, 2020;Tian et al, 2020).…”

Highly flexible Ag nanowire network covered by a graphene oxide nanosheet for high-performance flexible electronics and anti-bacterial applications

“…A flexible and transparent conductive electrode (FTCE) is a thin film with high transparency, high conductivity, and outstanding flexibility [1][2][3]. Due to the rapid advancements in flexible electronics and wearable devices, FTCEs have gained a great deal of attention as a key component of flexible displays [4][5][6], flexible touch panels [7][8][9], flexible thin film heaters (TFHs) [10][11][12][13][14][15][16], photoelectric devices [17][18][19][20], and wearable electronics [21][22][23].…”

“…A flexible and transparent conductive electrode (FTCE) is a thin film with high transparency, high conductivity, and outstanding flexibility [ 1–3 ]. Due to the rapid advancements in flexible electronics and wearable devices, FTCEs have gained a great deal of attention as a key component of flexible displays [ 4–6 ], flexible touch panels [ 7–9 ], flexible thin film heaters (TFHs) [ 10–16 ], photoelectric devices [ 17–20 ], and wearable electronics [ 21–23 ]. Currently, most flexible electronics and wearable devices use Sn-doped In 2 O 3 (ITO) film coated on a flexible substrate through a typical magnetron sputtering process [ 24–26 ] owing to the high conductivity and transparency of commercially available ITO films.…”

A Pressure-Insensitive Self-Attachable Flexible Strain Sensor with Bioinspired Adhesive and Active CNT Layers

“…To enhance the sensing performance of flexible tactile sensors, close conformal contact with the target substrates is essential [32][33][34]. Even if the sensors have outstanding intrinsic sensing capabilities, in the absence of close conformal contact with target objects, the sensors cannot properly detect the mechanical deformations of the objects, thereby drastically reducing the device sensitivity [11].…”