SOMA: Innovative silicone hand enables robots to delicately handle objects

The human hand has evolved into a highly precise instrument over millions of years of evolution. It is capable of skillfully polishing glassware, pressing stamps to affix them using a fist, dexterously reaching through narrow gaps, or typing rapidly on a computer keyboard. In all situations, the surrounding factors are always taken into consideration: fragile surfaces, confined spaces, different shapes, moving elements, and so on. For humans, this finesse in using our hands is just part of our nature. Rough robot grippers are still light-years away from achieving such sensitivity. But that’s all about to change.
In collaboration with European partners from business and industry, researchers from the Technische Universität Berlin (Technical University of Berlin – TU) are developing gentle hands for robots. Funded by the European Union, the project is being conducted under the name “SOMA” – short for “Soft Manipulation.” This technical term denotes sensitive gripping and lifting in service robotics. Air chambers which can be inflated with compressed air when needed have been integrated into the fingers on the hand of the robot (RBO Hand 2) which are made out of rubber-like silicone. The artificial hand is therefore able to gently wrap around objects without leaving any marks or scratches. It adapts precisely to the object’s shape: effortlessly succeeding in picking up pens, fruit, or a pair of glasses.
The “RBO Hand 2” developed at TU Berlin is very similar to a real human hand.

Radically new orientation

According to the Technical University of Berlin, SOMA represents a radically new orientation, due to the fact that robotic grippers have mainly been made out of metal up until now, crushing soft objects and costing thousands of euros. In contrast, it only costs up to 400 euros to produce the new silicone hands. The SOMA hand also offers further advantages, as it uses special computer programs to make observations about its environment and can therefore be used for a wide variety of purposes. For example, it can be employed outside the warehouse for apple harvesting or in service areas.

Gentle for fresh fruit

Robots that can handle fragile objects as well as hard objects, no matter the shape, size, or material, are in demand throughout the industry. The logistics industry in particular has shown great interest. While the transport of crates in warehouses is already fully automated, fragile goods must still be sorted and packaged by human hands in order to avoid damage. The British online supermarket Ocado, one of the SOMA project partners, has already tested the newly developed robot hands on artificial fruit. The result: It was able to remove many differently shaped test fruits from a standard-sized fruit box without causing any damage. “The RBO Hand 2 is a versatile, affordable, and reliable robot solution that integrates well into our highly automated warehouse,” says Graham Deacon, who leads the robotics research team at Ocado. His team plans on carrying out further, more complex tests with the sensitive hand in the months to come. The online supermarket operates several large-scale warehouses stocked with over 48,000 items. In the hope of expediting delivery and reducing costs, Ocado is on the hunt for a robust, automated process that will carefully get groceries ready for shipment.

SOMA Partners

  • Technische Universität Berlin (Faculty of Electrical Engineering and Computer Science)
  • University of Pisa
  • Italian Institute of Technology in Genoa
  • German Aerospace Center (DLR) in Munich
  • Institute of Science and Technology Austria
  • Online supermarket Ocado in Hatfield, Great Britain
  • Disney Research in Zurich

Text by Gesine Oltmanns
Photos: TU Berlin/Raphael Deimel