SciTech

Magnetic skin and robot soft sensing

The largest human organ is not the lungs or the stomach, but the skin. Protecting our sensitive internal workings from the elements, our skin serves an important purpose as both a barrier and a vehicle for sensory stimulation, without which we would be literal piles of flesh.

Unlike humans, robots can get along without any soft outer covering. Their metallic exteriors protect their sensitive electronics and their sense data, delivered via intricate arrays of sensors and circuits. But just because something works doesn’t mean it can’t be improved. Once again, Carnegie Mellon researchers have advanced the field of robotics by giving robots soft sensing through an outer layer of magnetic skin.

Conventional methods of detecting tactile sensations require a single wire connected to every contact point. "The wires might be fine inside hard cases such as smartphones and other devices, but if you're talking about fabric-skin or something else that's soft — then suddenly all those wires become sources of failure," explained Carmel Majidi, Associate Professor of Mechanical Engineering, in a university press release.

To solve this problem, Majidi and his colleagues at the Soft Machines Lab developed a silicon rubber skin that relies on magnetic field disturbances inside the skin when it touches another object. These disturbances are detected by a magnetometer, which then relays the information to central processing. The data can be used to infer the location and pressure of contact with the skin.

With this more streamlined method for detection of tactile sensations, the researchers were able to create “soft” robots that are more efficient and less prone to electrical or mechanical failures. This makes it possible for soft robots to more effectively fulfill their roles in sensitive industries, such as healthcare and assisted living for elderly or physically frail individuals. These are only two of the potential applications for this magnetic skin and the soft robots that it will cover, technology that could lead to exciting new robot designs that appear more science fiction than reality.

The magnetic skin is still in development, with the researchers experimenting on creating larger magnetic microparticles or placing the magnetometer in different locations to increase the magnetic field and sensitivity. If the magnetic skin becomes widely integrated, it could revolutionize soft robotics and soft sensing by broadening the limits of robot design, but also change our stereotypes of robots from hard, stainless steel automatons to machines that are capable of feeling similarly to us.

Another day, another step closer to the singularity.