An Innovative Laser-Processed NiTi Self-Biasing Linear Actuator

The revolutionary multiple memory material technology allows local modification of shape memory alloy functional properties to create monolithic actuators that exhibit several different thermomechanical characteristics. In this work, high density laser energy was used to process a monolithic piece of NiTi shape memory alloy material to allow synergistic pseudoelastic and shape memory effect behavior. The resulting actuator contains self-biasing properties eliminating the need for a separate biasing mechanism for cyclic actuation. The characteristics of these different local behaviors were analyzed using tensile testing and differential scanning calorimetry. The stress and strain amplitude of the self-biasing linear actuation was characterized with relation to input current control. This work provides proof of concept for local modification of martensitic and austenitic phases; enabling self-biasing linear actuation.