Nanomaterial‐Enabled Stretchable Conductors: Strategies, Materials and Devices

Abstract

Stretchable electronics are attracting intensive attention due to their promising applications in many areas where electronic devices undergo large deformation and/or form intimate contact with curvilinear surfaces. On the other hand, a plethora of nanomaterials with outstanding properties have emerged over the past decades. The understanding of nanoscale phenomena, materials, and devices has progressed to a point where substantial strides in nanomaterial-enabled applications become realistic. This review summarizes recent advances in one such application, nanomaterial-enabled stretchable conductors (one of the most important components for stretchable electronics) and related stretchable devices (e.g., capacitive sensors, supercapacitors and electroactive polymer actuators), over the past five years. Focusing on bottom-up synthesized carbon nanomaterials (e.g., carbon nanotubes and graphene) and metal nanomaterials (e.g., metal nanowires and nanoparticles), this review provides fundamental insights into the strategies for developing nanomaterial-enabled highly conductive and stretchable conductors. Finally, some of the challenges and important directions in the area of nanomaterial-enabled stretchable conductors and devices are discussed.

Nanomaterial-based stretchable and transparent electrodes

“…Another strategy is to blend conducting ions with stretchable transparent elastomers or hydrogels [92,93]. These approaches are well described in the previous literature [8][9][10].…”

“…Transparent electrodes are particularly important for optoelectronic devices such as organic light-emitting diodes (OLEDs) and organic photovoltaics. Accordingly, transparent electrodes with a stretchable form factor have been extensively studied for the realization of stretchable electronics [8][9][10]. As the conventional metals or transparent conductive oxides (e.g.…”

Ultrastretchable Fiber Sensor with High Sensitivity in Whole Workable Range for Wearable Electronics and Implantable Medicine

“…Here, the slope of the curve represents the gauge factor GF = (Δ R / R 0 )/ε, which represents the sensitivity to strain, where ε is the strain of the sensors. As shown in Figure 2a‐right1, a small strain (under 50%) decreased the contact area between the MWCNTs filled in a NTTF 27. As the strain increased from 50% to 275%, periodic bucklings perpendicular to the fiber axis gradually formed due to the reduction of the fiber diameter according to the Poisson effect, and the adjacent buckles began to contact one another (Figure 2a‐right2).…”

“…In general, three configurations can be employed to produce stretchable electronics: i) rigid functional device islands and stretchable interconnects; ii) intrinsically stretchable functional device components; and iii) a combination of (i) and (ii) 4. Although conventional metals and silicon have a certain degree of deformability by combining with the various stretchable structural designs, such as buckling,5 a wavy shapes,6 and a serpentine architecture,7 these materials cannot withstand dramatic mechanical deformation.…”

Two-beam laser fabrication technique and the application for fabricating conductive silver nanowire on flexible substrate

“…These deformable electronics and displays are applicable on curvilinear surfaces. Therefore, there has been a recent surge in the demonstration of metal nanowire fabricated on flexible substrates, such as polydimethylsiloxane (PDMS), 7 polyethylene terephthalate (PET), 8 and TiO films. 9 Such metal nanowire on flexible substrate has enabled not only conductivity but also excellent flexibility.…”