Failure modes of silver versus gallium-alloy conductive traces at flex-to-stretch interfaces

Failure modes of silver versus gallium-alloy conductive traces at flex-to-stretch interfaces

Presenter(s)

Josafat Jimenez

Comments

Presentation: 1:15-2:30, Kennedy Union Ballroom

Description

Traces made from a conductive liquid-metal ink are blade coated onto a Thermoplastic Polyurethane (TPU) substrate for flexible and stretchable applications. The same process is used for a silver flake composite ink to compare with liquid-metal samples. Uniaxial strain is applied to the samples to test resistance response of 2 mm-wide traces for both inks to investigate electrical loss and failure modes. Results show 10x increase from initial resistance at strains of 15% for silver composite inks and 140% for liquid-metal inks on average. The failure mode of the silver composite is attributed to intrinsic material loss under strain while failure for liquid-metal inks is due to localized strain at the interface between TPU and polyimide. Bilayer traces with both inks exhibit both positive ink qualities, showing silver-like initial resistance and liquid-metal-like strain tolerance. Finally, using a softer substrate of styrene-ethylene-butylene-styrene (SEBS) demonstrates higher straintolerance than TPU, without plastic deformation and lower resting state resistance creep after cycling.

Publication Date

4-17-2024

Project Designation

Independent Research

Primary Advisor

Alex M. Watson

Primary Advisor's Department

Engineering Management, Systems, and Technology

Keywords

Stander Symposium, School of Engineering

Institutional Learning Goals

Scholarship

Failure modes of silver versus gallium-alloy conductive traces at flex-to-stretch interfaces

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