Design and Optimization of an Origami-Inspired Foldable Pneumatic Actuator

A novel origami-inspired foldable pneumatic actuator is proposed in this letter to satisfy the comprehensive requirements in wearable assistive application. The pneumatic actuator combines the origami structure of designed Quadrangular-Expand pattern and the foldable pneumatic bellow. Integrated origami structure regulates the motion of actuator with high contraction ratio and enables accurate modeling. The origami framework also improves the strength of bearing negative pressure, and thus can provide bidirectional actuation. The workflow including design, fabrication and mathematic modeling of the pneumatic actuator is presented in detail. Based on the actuator modeling, the multi-objective optimization for parameters using Genetic Algorithm is then conducted to obtain the trade-off design. The verifications for static characteristics of output torque, as well as the dynamic characteristics of power density, mechanical efficiency and frequency response, have been conducted. In summary, the proposed actuator is powerful and energy-efficient.