Design of a Multi-connection Pneumatic Artificial Muscle

The pneumatic artificial muscle(PAM) has widespread applications from prosthetics, humanoid robots, continuum robots, and soft robots. Traditional PAMs imitate the movement mode of biological mus-cles, and control the contraction of muscles through the increase or decrease of internal pressure. PAMs have the advantages of light weight, high cleanliness, natural flexibility and safety. However, they also have problems such as a low contraction, difficult to change contraction force based on demand, and hard to adapt to soft systems. Human muscle is a kind of bundle structure. Multiple muscle fibers work together to make the muscle structure more stable and provide great power for human beings. Thus, we propose an improved Multi-connector pneumatic artificial muscle(MPAM), which is more similar to the structure of human muscle. Six self-made McKibben muscles, only 7 mm in diameter, are fixed into a bundle through Y-shaped multi-way valves. This structure can produce 8% more contraction ratio than the traditional McKibben muscles, and the number of muscle fibers can be increased or decreased according to different application scenarios. Due to its detachable nature, MPAM can be applied to a wider range of fields. The MPAM provide a simple new option for soft robotic actuation and has potential to push the development of the soft robot assistant suit.