Satoshi Takane1,2,Yuki Noda1,Naomi Toyoshima1,Tsuyoshi Sekitani1,2
Osaka University1,National Institute of Advanced Industrial Science and Technology (AIST)2
Satoshi Takane1,2,Yuki Noda1,Naomi Toyoshima1,Tsuyoshi Sekitani1,2
Osaka University1,National Institute of Advanced Industrial Science and Technology (AIST)2
Stretchable electronics have gained substantial interest due to their applicability in unconventional elastic, deformable devices such as epidermal/implantable healthcare sensors [1,2]. One-dimensional conductive material including metal nanowire is one of the promising candidates for stretchable electrode owing to their percolation network structure [3]. In this work, we investigate the effect of tensile strain on the conductivity of gold nanowire (AuNW) network electrodes with macroscale mesh structures (macromesh AuNW network electrodes) and the mechanism by which the macromesh structure affects its conductive property, for the purpose of maintaining a stable conductivity as the electrodes are stretched. We synthesized AuNW by solution phase reduction method and fabricated macromesh AuNW network electrodes with three different mesh designs of square, rhombic, serpentine. In strain-resistance test, the serpentine macromesh electrode exhibited a relative resistance change (<i>ΔR/R<sub>0</sub></i>) of 11 under 150% tensile strain, as opposed to 30 for AuNW network electrodes without a macromesh structure. Among the three mesh designs, serpentine showed the smallest relative resistance changes, followed by rhombic and square. Using microstructural analytic model [4], we revealed that resistance changes in the macromesh AuNW network electrodes depend on the electrode stretching direction and the current flow direction determined by the macromesh design [5]. This is different from the mechanism in the case of macromesh electrodes with vacuum deposited gold, where the resistance change depends on the tensile stress distribution in the mesh design. Our experimental results and microstructural analysis establish a basis for optimizing the macromesh design for metal nanowire networks used in stretchable electrodes.<br/>[1] S. Niu, <i>et al.</i>, <i>Nat. Electron.</i> <b>2</b>, 361-368, (2019).<br/>[2] S. Choi, <i>et al.</i>, <i>Nat. Nanotech.</i> <b>13</b>, 1048-1056, (2018).<br/>[3] P. Lee, <i>et al.</i>, <i>Adv. Mater.</i> <b>24</b>, 3326-3332, (2012).<br/>[4] L. Jin, <i>et al.</i>, <i>Proc. Natl. Acad. Sci. U. S. A.</i> <b>115</b>, 1986-1991, (2018).<br/>[5] S. Takane, <i>et al.</i>, <i>Appl. Phys. Lett.</i> <b>118</b>, 243102, (2021).