Scientists Develop Biologically-Inspired Artificial Skin for Robots

Scientists from the Technical University of Munich have developed a biologically inspired artificial skin for robots to make them safer for working around humans. The researchers state the synthetic skin, combined with control algorithms, allows robots to sense their own bodies and surroundings, aspects that are crucial when working around humans. The team used their technology to create the first autonomous humanoid robot with full-body artificial skin capable of providing hugs without injuring anyone, which isn’t as trivial as it may sound, considering some robots can exert forces strong enough to break bones.

The artificial skin was made using a series of hexagonal cells about an inch in diameter, with each outfitted with a microprocessor and a set of sensors that detect contact, proximity, acceleration, and temperature. The cells were actually designed 10 years ago by Professor of Cognitive Systems (at TUM) Gordon Cheng, but have only now have been utilized for their full potential.

Getting artificial skin to ‘feel’ or sense outside stimuli is a complicated process, especially when the human version has 5-million receptors that let us feel everything from heat to a pinprick. Previous systems that tried to approximate human skin quickly became overloaded with processing sensor data from a few hundred sensors. To put that into perspective, the scientists’ H-1 robot is outfitted with 1,260 sensor cells covering its body.

To overcome the data processing issue, the team doesn’t monitor the sensors continuously, but rather an event-based system where the sensors only transmit data when their values have changed due to an event. The robot uses the data to ‘sense’ and adapt to its environment. For example, the artificial skin on its feet allows it walk on uneven flooring or even balance on one leg if needed. On the hugging aspect, the robot uses the skin on its torso to detect contact at many different points, which lets it perform the act without damaging us humans. What’s more, since the artificial skin consists of many individual cells if one becomes damaged the others continue to function normally.

According to Cheng, “Our system is designed to work trouble-free and quickly with all kinds of robots. Now we're working to create smaller skin cells with the potential to be produced in larger numbers.”