The Collaborative Design Optimization of Structure and Fabrication Process Parameters for Compound Twisted and Coiled Actuators

Compound Twisted and Coiled Actuators (CTCAs) are promising candidates for artificial muscles due to their exceptional capability to generate large output forces and achieve long strokes. However, their thermal actuation performance is influenced not only by structure parameters but also by the parameters of the fabrication process. To further enhance their performance, an innovative collaborative design optimization method for structure and fabrication process parameters is proposed, in which both the fabrication process and structure parameters of the CTCA are optimized simultaneously to maximize contraction displacement. Based on the response surface method, a coupling model is established that describes the performance of the CTCA with respect to both structure and fabrication process parameters. An optimization algorithm based on Genetic Algorithm is proposed to maximize contraction displacement of the CTCA. The CTCA prototypes are fabricated, and thermal actuation experiments are conducted. The experimental results show a significant performance improvement, with a maximum contraction strain of 55.4% and a maximum output force of 5N at 80°C. driving temperature.