A 3D printable artificial muscle capable of lifting 1000 times its weight

Small, but strong… An artificial muscle designed by Italian researchers would be able, according to their latest research, to lift up to 1000 times its weight. The secret of this strength lies in the resin chosen for its manufacture as well as in the design of the “muscle” structure.

The research of this team from the Italian Institute of Technology is based on a particular type of actuator. What is called an “actuator” is a device that converts a signal and energy into movement. In this case, it is a pneumatic mechanism capable of contracting and relaxing, like a muscle.

Indeed, nature has provided us with machinery that engineers still struggle to match in many ways. ” Although artificial actuators have achieved the performance of muscle contraction, the versatility and grace of movements achieved by complex muscle arrangements remain largely unmatched. “, underline the scientists in their research document, published in the journal Scientific robotics.

So they created a device that partly mimics certain characteristics of muscles. They named their creation ” Geometry-based actuators that contract and expand » or GRACE (in French, « Geometry-based actuators that contract and expand “). They used a specific resin that gives the actuator great flexibility and good resistance. This was structured to form the muscle via 3D printing. Another special feature: GRACE was designed in one piece. So there is no part to assemble. On the other hand, the researchers composed this rounded shape extremely precisely, following a very precise mathematical model that they established beforehand. Pleats built into the membrane allow for optimal elongation and contraction, providing added strength and flexibility to the artificial muscle.

8kg load for an 8 gram muscle

Thanks to this method, the scientists say they have managed to create an 8 gram actuator capable of lifting up to 8 kg of load. Or 1000 times its weight, which represents a notable performance.

The team then continued their experiments by combining several of these actuators. In order to create what looks like a robotic hand, they assembled no less than 18 actuators of different sizes. As can be seen in the video below, the hand was able to move quite smoothly. By using the right actuators as needed, the scientists were able to make it perform different types of movements. The hand can therefore bend the fingers, simultaneously or individually, turn the wrist, twist the palm at different angles…

However, the researchers are still working on improving the properties of their artificial muscle. They are counting in particular on the new resins that could be developed in the future, in particular to benefit from better tensile properties in order to further increase the capacities of this type of 3D printable device.

Source: Science Robotics

Video showing the muscles in action (proposed by the new scientist):