This project was an experiment into the capabilities of Nitinol shape memory alloy actuators. I built a system that resembles a traditional servo by having 2 opposing coils twist a potentiometer providing positional feedback. The coils are actuated by a pulsing signal from an Arduino, and pulses at lesser widths as the servo approaches the designated midpoint.

The range of the servo is dictated by the max reasonable Stretch of the opposing coil. Better mechanical designs would yield higher range. The servo was able to find and hold any position within the range and followed the lower desired position pot as it was twisted.

Performance was limited by the Arduinos simplistic code and required delays. Problems include: slower position response, jumping past the desired position, and random actuations due to the Arduino. A non-linear feedback system would better model the position, and an FPGA would better drive multiple of these actuators with greater precision.