Moving beyond flexible to stretchable conductive electrodes using metal nanowires and graphenes

Abstract

Stretchable and/or flexible electrodes and their associated electronic devices have attracted great interest because of their possible applications in high-end technologies such as lightweight, large area, wearable, and biointegrated devices. In particular, metal nanowires and graphene derivatives are chosen for electrodes because they show low resistance and high mechanical stability. Here, we review stretchable and flexible soft electrodes by discussing in depth the intrinsic properties of metal NWs and graphenes that are driven by their dimensionality. We investigate these properties with respect to electronics, optics, and mechanics from a chemistry perspective and discuss currently unsolved issues, such as how to maintain high conductivity and simultaneous high mechanical stability. Possible applications of stretchable and/or flexible electrodes using these nanodimensional materials are summarized at the end of this review.

Novel transparent conductor with enhanced conductivity: hybrid of silver nanowires and dual-doped graphene

“…That is, the hybrids of Ag NWs and conductive nanostructures have been developed with a combination of different nanomaterials, including carbon nanotubes, conductive polymers, metal oxide, and graphene [4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Especially, hybridization of Ag NWs with a two-dimensional graphene appears to be promising to address various issues.…”

“…To address the problems of Ag NW networks, it has been a highlight to introduce Ag NWs with a secondary conductive nanostructure to form a hybrid for forging inter-nanowire connection and enhancing performance [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. That is, the hybrids of Ag NWs and conductive nanostructures have been developed with a combination of different nanomaterials, including carbon nanotubes, conductive polymers, metal oxide, and graphene [4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

Metal‐Nanowire‐Electrode‐Based Perovskite Solar Cells: Challenging Issues and New Opportunities

“…MeNW-network electrodes have been considered to be more suitable, because of the mechanical stability against dimensional deformation along with excellent optoelectrical properties, represented by transparency and sheet resistance, comparable to those of ITO layers. [15,129] Accordingly, several groups have made efforts to employ MeNW-network electrodes as a transparent electrode ( Table 2). [90,98,99,[130][131][132] Schematic illustrations of each type of PSC employing flexible MeNW-network electrodes are presented in Figure 6.…”

From stretchable to reconfigurable inorganic electronics

“…Some initial work towards this goal began by fabricating stretchable electronics on polymeric substrates, such as polydimethylsiloxane (PDMS), polyethylene terephthalate and polyethylenimine (Figure 2a). The mechanical elasticity of these polymers suppresses strain localization on the relatively rigid metal layers, leading to the realization of bendable and stretchable devices for applications in stretchable displays, artificial skin, monitoring systems and bio-integrated devices [36] . However, the deposition of metal interconnects on top of polymeric substrates has its limitations: this technique gives rise to three possible modes of failure, such as slipping, cracking and delamination, seen in Figure 2b [36] .…”

“…The mechanical elasticity of these polymers suppresses strain localization on the relatively rigid metal layers, leading to the realization of bendable and stretchable devices for applications in stretchable displays, artificial skin, monitoring systems and bio-integrated devices [36] . However, the deposition of metal interconnects on top of polymeric substrates has its limitations: this technique gives rise to three possible modes of failure, such as slipping, cracking and delamination, seen in Figure 2b [36] . For example, elastic breakdown of metal films under only a small applied strain can cause microcracks that propagate in the metal eventually cause electrical discontinuity and delamination results from an accumulation of strain stress on the rigid metal conductor [37][38][39] .…”