Biaxially stretchable transparent conductors that use nanowire networks

Stretchable transparent conductors are required for flexible and wearable electronics. This study demonstrates biaxially stretchable transparent conductors that use silver nanowire networks. The use of buckled nanowire networks has previously been reported to lend stretchability to the transparent conductor in a single axis. However, a nanowire network that is prestrained and then buckled out-of-plane biaxially shows a deterioration of the electrical conductivity after a single cycle of stretching and releasing the strain uniaxially. This has been attributed to the loss of good electrical contact between the nanowires. By hot pressing the out-of-plane buckled nanowires to obtain an in-plane wavy nanowire network with good wire-to-wire junctions, a biaxially stretchable transparent conductor that maintains good electrical conductivity with stretching up to 10% is demonstrated. The methods of prestraining the nanowire network to achieve out-of-plane buckled nanowires and hot pressing the out-of-plane buckled nanowires to obtain an in-plane wavy nanowire network with fused junctions are expected to be practical for other classes of percolative networks based on one-dimensional (1D) materials used in flexible and stretchable applications.