Axiomatic Design of Equipment for Analysis of SMA Spring Degradation During Electronic Actuation

The Shape Memory Alloy, Nickel-Titanium i.e. Nitinol is greatly lacking in published research about its properties. Both degradation through electronic actuation and degradation through heat actuation are lacking, as well comparison of them. This means that both inventors and manufacturers are missing important information, limiting their ability to reliably apply the material in the soft robotic field, automotive design, consumer electronics, or aerospace. Accurate and reliable testing equipment is essential to gather needed data about the material for further development. This paper presents a static test bench for SMA springs that is designed according to Axiomatic Design Theory. The tester is designed to actuate and measure six springs at a time to increase the rate at which testing data is gathered. The measurements collected are the force, current, and temperature of each spring along with the ambient temperature. The test bench was successfully designed and built. An initial test run lasted for two days for approximately 6700 cycles; no springs experienced a complete failure.