PhD Seminar: "Combining Nanostructures for Highly Stretchable and Better Performing Conductive Ink" by Muhammed Kayaharman

Candidate: Muhammed Kayaharman

Title: Combining Nanostructures for Highly Stretchable and Better Performing Conductive Ink

Date: August 8, 2022

Time: 11:30 AM

Place: REMOTE 

Supervisor(s): Goldthorpe, Irene

Abstract:

A printable conductive ink which is both highly conductive and stretchable is highly desired for flexible and wearable electronics. However, current state-of-the-art inks, which contain either silver flakes or nanoparticles, show high change in electrical resistance under strain cycling. In this work I instead use silver nanowires as the conductive filler to achieve a much more mechanically flexible ink. The conductivity can be as low as 0.93 x 10-5  ·cm, and the resistance increases by only 5X after 250 cycles of 30% strain and remains conductive to at least 500% strain. I found the reason behind the high stretchability of nanowires is their long thin shape, which allows for an ink with a low metal fill and leads to a higher tensile strength compared to other state-of-the-art inks.

Based on these findings, I recently considered high aspect-ratio carbon-fibers as a cost-efficient alternative to silver nanowires. I will present my study on mixing carbon-fibers into silver-flake inks to improve their mechanical properties. I will also summarize my future plans on evaluating other nanostructures for flexible inks, and the fabrication of a fully-printable, stretchable, graphene oxide transistor.