High-Speed and Low-Energy Actuation for Pneumatic Soft Robots with Internal Exhaust Air Recirculation

Multichamber soft pneumatic actuators (m-SPAs) are widely used in soft robotic systems to achieve versatile grasping and locomotion. However, existing m-SPAs have slow actuation speed and are either limited by a finite air supply or require energy-consuming hardware to continuously supply compressed air. Herein, these shortcomings by introducing an internal exhaust air recirculation (IEAR) mechanism for high-speed and low-energy actuation of m-SPAs are addressed. This mechanism recirculates the exhaust compressed air and recovers the energy by harnessing the rhythmic actuation of multiple chambers. A theoretical model to guide the analysis of the IEAR mechanism, which agrees well with the experimental results, is developed. Comparative experimental results of several sets of m-SPAs show that the IEAR mechanism significantly improves the actuation speed by more than 82.4% and reduces the energy consumption per cycle by more than 47.7% under typical conditions. The promising applications of the IEAR mechanism in various pneumatic soft machines and robots such as a robotic fin, fabric-based finger, and quadruped robot are further demonstrated. An interactive preprint version of the article can be found at: .

Automated summary

Multichamber soft pneumatic actuators (m-SPAs) are widely used in soft robotic systems, but they have slow actuation speed and require continuous supply of compressed air. To address these issues, this study introduces an internal exhaust air recirculation (IEAR) mechanism for high-speed and low-energy actuation of m-SPAs. Comparative experiments show that the IEAR mechanism significantly improves actuation speed and reduces energy consumption per cycle under typical conditions. The study also demonstrates the promising applications of the IEAR mechanism in various pneumatic soft machines and robots.