Wednesday, October 5, 2022

E-skin with artificial hairs perceives touch from different directions

We have robots that can see, walk, talk, hear, and manipulate objects in their robotic hands. We even have a robot that can smell. But what about the sense of touch? Researchers are also attempting to replicate human touch in robots using artificial intelligence.

A team of researchers from the Chemnitz University of Technology and Leibniz IFW Dresden has developed a new type of sensitive electronic skin (e-skin) with integrated artificial hairs. The tiny surface hair can perceive and anticipate the slightest tactile sensation on human skin and even recognize the direction of touch.

Researchers have fabricated high-density integrated active-matrix magnetic sensors with three-dimensional (3D) magnetic vector field sensing capability. The 3D magnetic sensor is composed of an array of self-assembled micro-origami cubic architectures with biased anisotropic magnetoresistance (AMR) sensors manufactured in a wafer-scale process.

The research team has succeeded in integrating the 3D magnetic field sensors into an artificial e-skin with embedded magnetic hair, enabling real-time multidirectional tactile perception. The e-skin is made of an elastomeric material into which the electronics and sensors are embedded – similar to organic skin, which is interlaced with nerves.

The sensor matrix is not only able to register the bare movement of the hair but also determines the exact direction of the movement. Each hair on the e-skin becomes a full sensor unit that can perceive and detect changes in the vicinity. The magneto-mechanical coupling between the 3D magnetic sensor and magnetic hair root in real-time provides a new type of touch-sensitive perception by an e-skin system.

“Our approach allows a precise spatial arrangement of functional sensor elements in 3D that can be mass-produced in a parallel manufacturing process,” said Christian Becker, a Ph.D. student in Prof. Schmidt’s research group at MAIN and the first author of the study. “Such sensor systems are extremely difficult to generate by established microelectronic fabrication methods.”

The artificial electronic skin can be used in a range of applications, from skin replacement and medical sensors on the body to artificial skin for humanoid robots and androids.

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