Novel Embroidered Actuator Fabrication and Design Optimization

Abstract

McKibben actuators have extensive applications in soft robotics and wearables; however, traditional manufacturing processes limit their ability to tailor design parameters to specific applications. This thesis explores a novel fabrication method for these actuators: using an embroidery machine to create the ‘outer mesh,’ thus allowing for variation of backing material and embroidery pattern. Having tested and iterated through six assembly processes, the most reliable method is presented, beginning with digital embroidery pattern creation and concluding with the final actuator assembly. Additionally, the actuators are characterized to illustrate how varying the design parameters affects performance. The effect of pressure on actuator movement is explored, and it can be seen that as pressure increases, actuator curvature increases. Out of the three embroidery backing materials explored – felt, cotton, and polyester – felt had the greatest curvature until 24psi, beyond which polyester surpasses it. This work also shows that the addition of embroidery onto the backing material decreases curvature and that varying the embroidery patterns results in different decreases. The resulting curvatures in all these experiments demonstrate how the response of embroidered actuators can be tailored to meet the design requirements for specific uses. Finally, different applications of these actuators are explored, and a robotic hand for which the actuators have been used as fingers is shown.