Programmable Actuation in Bubble-Cast Soft Robotics

Abstract

Soft robotics is a rapidly growing field with applications ranging from medical devices and healthcare to industrial manufacturing and assembly. These systems excel in environments that require adaptable and flexible interactions, presenting opportunities for innovation in areas where traditional rigid robots are less effective. Challenges in soft robotics include the complex tethering systems, control precision, and the rigidity of actuation inputs, which limit the practical applications of soft actuators. This thesis proposes a new approach to soft robotic actuation by introducing programmability into the mold design of an existing soft robotic manufacturing method. Modifying the cross sectional properties of actuators more flexibly during the manufacturing phase paves the way for tailored mechanical responses under uniform pressure inputs.

Our study introduces a method for selectively modifying cross-sectional properties of bubble-cast actuators, directly affecting their bending behavior and curvature upon actuation. We validate this new method by modifying the cross-section along the length of a single actuator and analyzing the curvature behavior. We establish and test a more quantifiable relationship between applied pressure and curvature ranges of actuation using an experimental setup and a visual data analysis approach, offering a significant step forward in the design and functionality of soft robotic systems. This thesis also explores how these dynamics can be precisely controlled through structural variations within the actuator itself, setting the stage for achieving distinct mechanical responses based on predefined geometric configurations. The implications of this research extend to improved designs of soft actuators for various applications, highlighting the potential for untethered soft robotic systems with intrinsic mechanical control parameters. Ultimately, the research contributes to the field by detailing the manufacturing, testing, and validation of a technique that not only expands the scope of the fabrication process but also enhances the functional diversity of soft actuators, broadening the potential for adoption in industrial and medical applications.