Since the project begin in September 2023, the SARA team has developed an unprecedented robotic arm with three degrees of freedom powered by artificial muscles. These constitute of an elbow joint, wrist rotation and a gripping mechanism actuated with HASEL actuators, and further three degrees of freedom are added through a motorized shoulder joint.

Why?

The mission is to develop a new breed of robotic arms using soft actuators. These devices can mimic the functionality of human muscle tissue, endowing robotic devices with unparalleled lightweight and humanoid agility, which would mean a major improvement in prosthetic applications.

Who?

The SARA team consists of ten mechanical engineering students from ETH Zurich.

Why soft actuators for our arm?

Conventional Actuators

Conventional electromechanical and fluidic actuators are widespread due to their accuracy and resistance to stresses. However, their rigidity limits their range of motion and inhibits a capability to adapt to new circumstances, apart from the fact that their metal components make them heavy. There has thus been a new lineage of research in developing actuators consisting out of soft materials and being able to respond dynamically such as systems found in nature.

Soft Actuators

Soft Actuators are actuators composed of soft materials that deform when triggered. They can contract and relax in a very natural and muscle-like manner, which makes them the perfect choice for SARA. These devices come in various types, shapes and sizes, and can be driven pneumatically, thermally or electrostatically, to mention just a few. In recent years, soft actuators have been increasingly used to challenge the boundaries of biorobotics and to make more versatile and natural moving robots.