Authors: P.D. Fallon, A.P. Gerratt, B.P. Kierstead, R.D. White
Affilation: Tufts University, United States
Pages: 470 - 473
Keywords: nitinol, SMA, actuator, robot
Shape memory alloy (SMA) microactuators are under development for use in soft bodied robotics. These actuators take advantage of the shape memory effect of nickel-titanium alloys (nitinol) to deliver high force and large strain in a solid-state, thin film actuator. The actuators will be used for generating motion in an all-soft-material robotic platform that attempts to mimic some of the features of the tobacco hornworm caterpillar, Manduca Sexta. The devices described in this work are unique due to their thin patch-like structure, which will allow them to be laminated onto, or embedded into, the soft wall of the robot. The actuator patches consist of a nitinol microwire on a flexible polyimide base. The overall dimensions of the patches vary from 7.75 x 3.5 mm to 22 x 10 mm. The wires are 0.1 -0.8 mm wide. The polyimide is photodefined in a mesh structure so that the sheet is much more compliant in tension and compression than a flat sheet. The nitinol microwire meanders across the polyimide structure in what may be considered a planar imitation of a coil spring. Characterization of the SMA actuators is ongoing.