Compliant materials could fly as well as protect hospital patients
Compliant systems, which transmit forces without using joints, are in the process of being brought to market in hospital beds but also show potential for use in medical tools, robot grippers and aircraft wings.
Such systems are being studied under the direction of Flavio Campanile at the Swiss Federal Laboratories for Materials Testing and Research – EMPA.
A robot gripper arm developed by the team uses the technology to reduce complexity to only 32 individual parts, is 60% lighter than its conventional equivalent and costs 98% less to manufacture.
Michael Sauter, one of Campanile's colleagues, showed in a feasibility study that a special bed using compliant structures could be used to prevent bedridden patients from developing bed sores. As well as winning various awards, the idea has now been spun off into a new company, Compliant Concept GmbH, to bring the nursing bed to market in the near future.
The idea of using compliance is in itself not new. Popular fishing boats developed by the US company, Hobie Cat depend on compliant fins for their patented MirageDrive propulsion system and Festo has developed compliant 'Fin Ray' effect actuators. Hobie's MirageDrive fins are moved from side to side by pedals as a more efficient and much cheaper alternative to a propeller or paddle wheel.
US 1982 Patent 4,312,486 also describes an aircraft wing that adapts its shape to suit airflow, and Campanile is convinced that the idea can be used to construct such wings which would allow aircraft to be built that could move more elegantly and more economically through the air. "Sooner or later it will be possible to make wings without ailerons, flaps and thousands of individual parts. They will have in principle only one component, which continually changes shape," Campanile said.
