Scientists at the Technical University of Munich (TUM) have constructed the first autonomous humanoid robot with full-body artificial skin.
Researchers have been investigating artificial skin since the 1970s. However, creating a skin-like covering that’s as sensitive as human skin is not an easy task. As human skin has about five million receptors, it’s challenging for fake skin to understand so much data. The computing capacity networks typically run into problems after trying to compute data from just a few hundred sensors. According to TUM, one robot with a similar number of receptors would need an entire building full of computers just to process the information.
This new system, which greatly reduces the processing energy that a humanoid robot needs to function, is composed of skin cells developed by Dr Gordon Cheng a decade ago. Each hexagonal cell is about an inch (about 2.4 cm) in diameter and equipped with a microprocessor and sensors to observe factors such as acceleration, temperature, proximity and contact. The cells help robots to experience their surroundings with more detail and sensitivity, enabling them to operate more safely around people and avoid accidents, similar to a human.
Now, Dr Cheng’s innovation is closer to reaching its full potential. By using a neural engineering approach, Dr Cheng and his team monitor the cells with an event-based system, rather than observing them continuously. In other words, the cells only transmit data from their sensors when the values are changed—reducing the processing effort needed by up to 90 percent.
According to TUM, the human nervous system functions in a similar way. After putting a hat on, the average person gets used to the sensation of wearing it. There’s no need to continuously notice it unless the wind blows it off, for example, which helps the nervous system focus on other sensations and events that do need a response.
Using the event-based approach, Dr Cheng and his team can now apply synthetic skin to the H-1—a human-sized autonomous robot. The H-1 uses 1,260 cells with more than 13,000 sensors throughout its entire body, increasing its “bodily sensation.” As an example, the cells on the soles on its feet can react to uneven floor surfaces and even balance on one leg.
With its numerous sensors, the robot can accurately sense humans and function without hurting them, even processing the complex information and pressure needed to give someone a hug.
“This might not be as important in industrial applications, but in areas such as nursing care, robots must be designed for very close contact with people,” Dr Cheng explained in a statement.
The artificial skin system is robust, versatile and can work even if some cells stop working. Dr Cheng and his team are now trying to improve the system, so it can be produced at scale and in several fields.
“Our system is designed to work trouble-free and quickly with all kinds of robots,” Dr Cheng said. “Now we’re working to create smaller skin cells with the potential to be produced in larger numbers.”