Wednesday  |  Conference Center A  |  02:50 PM–03:10 PM

#13411, High-Throughput Tensile Testing of Silver Nanowires

Due to their small size, high strength and high conductivity, silver nanowires have been used in innovative applications such as sensing, actuation, interconnects, nanoelectronics, and other nanoelectromechanical systems (NEMS). Likewise, when used in transparent conductive films to improve their conductivity, they have been considered to be a more cost-effective substitute to indium-tin oxide (ITO) in touch displays.

Studying the mechanical properties of nanowires is important, due to the dependence of their elasticity and the increasing of the yield-strength with the reduction of diameter. In the past, due to challenges in sample preparation, tensile testing of silver nanowires has been limited to a small number of samples. This causes the results to have limited statistical significance, for example for the case of fracture strain, which should be a stochastic variable.

Here, we created channels on a microfluidic chip. This allowed us to pour a suspension of silver nanowires and align them to the flow direction over a polymer substrate, achieving high density and alignment. Then, a tensile test was performed on the substrate capturing images of the deformation of the nanowires at regular intervals. These images were stabilized, and several nanowires were selected to analyze their fracture strain, using digital image correlation (DIC). The program identified the frame in which the fracture of the nanowire occurs, and the strain was obtained using the data of said frame. The program also calculates the position in which the fracture occurs, and we could see that it was approximately in the middle of the nanowires, as predicted by theory. Complementary simulations in Abaqus show that small angular misalignments do not impact significantly the theoretical model used to analyze the results. We show results for more than 200 samples, achieving a statistical quantification of fracture strain of nanowires, useful for the design of applications based on them, such as stretchable electronics.

Brizeida Ojeda   University of Texas at Dallas
Al-Mustasin Hossain   University of Texas at Dallas
Rodrigo Bernal   University of Texas at Dallas