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Gentle strength for robots
Elastic machines: Membranes surrounding sealed, air-filled chambers can be used as actuators, facilitating risk-free contact between humans and robots. Compliant electrodes are attached to each side of the membrane and cause it to stretch when voltage is applied. The membranes are bistable, meaning that they can enclose two different volumes at the same air pressure. A membrane switches from its more compact state to its stretched state when voltage is applied to its electrodes. Even in the case of three or more linked, bubble-shaped chambers, one can be controlled in this way so that it inflates to a larger volume, thereby exerting force. © Photo: Alejandro Posada / MPI for Intelligent Systems

Gentle strength for robots

A soft actuator using electrically controllable membranes could pave the way for machines that are no danger to humans

In interacting with humans, robots must first and foremost be safe. If a household robot, for example, encounters a human, it should not continue its movements regardless, but rather give way in case of doubt. Researchers at the Max Planck Institute for Intelligent Systems in Stuttgart are now presenting a motion system - a so-called elastic actuator - that is compliant and can be integrated in robots thanks to its space-saving design. The actuator works with hyperelastic membranes that surround air-filled chambers. The volume of the chambers can be controlled by means of an electric field at the membrane. To date, elastic actuators that exert a force by stretching air-filled chambers have always required connection to pumps and compressors to work. A soft actuator such as the one developed by the Stuttgart-based team means that such bulky payloads or tethers may now be superfluous.


pi Metin Sitti
Metin Sitti
pi Lindsey Hines
Lindsey Hines
pi Kirstin Petersen