Online

Gopalkrishnan, Akiva

Mechanical Engineering

2022

M.S.

Tin doped Indium oxide currently is the dominant material used in the field of transparent electronics (TE) but suffers from Indium scarcity and brittle failure under small deformations. Silver Nanowires (AgNWs) are of considerable research interest due to their relative ease of fabrication, high conductivity, and mechanical ductility, as well as high corrosion stability. Existing research on single AgNWs via nanomechanical testing has shown an increase in the strength and ductility as both the diameter and gauge length is reduced, or a "smaller is stronger effect". The formation of a network structure of AgNWs on flexible plastic substrates is essential for the integration of AgNWs in the field of transparent electronics. For applications requiring large stretchability, AgNWs are embedded on a polydimethylsiloxane (PDMS) substrate via spin coating. Experimental tensile testing methods as well as theoretical methods like percolation theory that measure the increase in the resistance of the embedded AgNW-PDMS substrate, have indicated a mode of failure at the nanowire junctions. The objectives of this thesis are threefold: To characterize the structure of a spin coated nanowire network using SEM imaging, to simulate the structure of the AgNW network based on the characteristic length and diameter, to perform a finite element analysis of the simulated AgNW network embedded in a PDMS substrate to simulate yielding a the AgNW junctions due to tensile loading. It was found that the material properties of individual AgNW could be successfully incorporated in a finite element model to simulate the tensile deformation of an entire embedded AgNW network which included yielding at the junctions.