Device and method for the thermo-electro- mechanical characterization of microscale wires

An electro-thermo-mechanical tensile testing device for wires, comprising:

• a sample frame comprising an upper part and a lower part, with the upper part coupled to the lower part through a plurality of sacrificial supports, the upper part and the lower part each comprising an electrical contact pad, wherein the upper part and the lower part are electrically non-conductive;
• a wire sample comprising a plurality of tracking beads, the wire sample affixed to the upper part and the lower part such that the electrical contact pad of the upper part is communicatively coupled to the electrical contact pad of the lower part through the wire sample;
• a piezo actuator coupled to the upper part;
• a weight of known mass coupled to the lower part;
• a DC power supply communicatively coupled to the wire sample through the electrical contact pads of the upper part and the lower part, the DC power supply configured to pass a current through the wire sample;
• an electronic balance positioned beneath the weight, with the weight resting on the electronic balance;
• and
• a digital camera pointed at the wire sample within the sample frame such that the tracking beads on the wire sample are visible.

A method for the thermo-electro-mechanical characterization of wires, comprising:

• affixing a wire sample to a sample frame, the sample frame comprising a plurality of sacrificial supports connecting an upper part of the sample frame with a lower part of the sample frame, the upper part and the lower part each being electrically non-conductive and each comprising an electrical contact pad, wherein the wire sample is affixed to the sample frame such that the electrical contact pad of the upper part is communicatively coupled to the electrical contact pad of the lower part through the wire sample;
• coupling the upper part of the sample frame to a piezo actuator above the sample frame;
• coupling the lower part of the sample frame to a weight of known mass below the sample frame, the weight located on an electronic balance;
• communicatively coupling the wire sample to a DC power supply through the electrical contact pads of the sample frame;
• destroying the sacrificial supports, making the wire sample the only connection between the upper part and the lower part;
• applying a desired current to the wire sample using the DC power supply;
• waiting for thermal changes in the wire sample due to Joule heating from the applied current to reach a steady state;
• applying a force on the wire sample by displacing the upper part of the sample frame upward using the piezo actuator;
• simultaneously capturing images of tracking beads on the wire sample with a digital camera and weight measurements from the electronic balance, at regular intervals while the upper part is being displaced upward, until the wire sample fails;
• and
• determining stress values and strain values using the captured images and weight measurements.