Design optimisation of soft silicone pneumatic actuators using finite element analysis

The current trend in soft robotic solutions is to pneumatically actuate chambers within manipulators that feature elastomeric material. This work describes the development of a repeating module actuator with each module capable of producing 3 degrees of freedom, as well as longitudinal expansion, intended for use as a laparoscopic tool in minimal invasive surgery. The design of the manipulator geometry as well as the choice of suitable material is dependent on the application, range of motion, and the suitable actuation pressure. This work describes the use of finite element analysis to simulate the range of motion of the hyperelastic response of two different soft silicones. Different geometry ratios and channel designs of the actuator are then optimized in terms of bending angle, maximum stress generated, radial expansion due to air pressure, and the amount of free area that the design allows in the actuator for other tools necessary in laparoscopic surgery. The optimum geometries are then selected as candidates for the development of the repeating module design, and the addition of skins to the module is investigated for the optimized module design