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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