An ultra-sensitive bionic finger creates 3D images of the object under study

Doctors have many ways to look under our skin, including MRI, X-rays and sonograms.Chinese researchers from Wuyi University have created a robotic finger that can offer a different way of analysis. Their bionic finger can detect structures such as blood vessels, tissues and bones that are located under the skin.

"We were inspired by human fingers, which have the most sensitive tactile perception of all known to us," says senior author Jianyi Luo, a professor at the university. "For example, when we touch our fingers to our body, we can feel not only the texture of the skin, but also the outlines of the bones under it."

The bionic finger is actually more like a tattoo machine. It works by repeatedly touching the tip, which methodically scans the surface. The tip is made of carbon fibers, which shrink to a greater or lesser extent when they collide with soft or hard materials.

Based on its own compression, as well as on the reaction of the material it encounters, the bionic finger is able to create 3D images of what it touches. Not only the surface is scanned, but also the structures under it.

During the tests, the finger was presented with various structures that needed to be displayed. Among them was a hard letter "A", covered with a layer of soft silicone, as well as many other forms, from soft to hard, also covered with silicone. The finger could not only easily display the letter, but also successfully identify soft shapes under silicone.

To test how a bionic finger will cope with the task of mapping a person, a team of researchers created structures consisting of artificial bones and muscle tissue made of silicone. They found that the probe's touch was sensitive enough to find simulated blood vessels embedded in artificial tissue.

"Similar to palpation [a method of examining a patient performed by a doctor's hands], a bionic finger can recognize simple tissue structures of the human body, but there is still some work to be done to recognize complex three-dimensional structures," the researchers write. - It is important to note that the bionic finger can reconstruct the 3D profile of tissue structures, which makes palpation visual and scientific. Overall, these results show fantastic prospects for subsurface tactile tomography for use in the human body."

The researchers also believe that the bionic finger system could be useful for finding bugs in flexible electronics, such as wearable sweat-powered batteries and stretchable display screens. To test the theory, they ran their finger over the flex circuit system, and it successfully detected an improperly drilled hole and an area where there was a gap preventing the system from working properly.

The study was published in the journal Cell Reports Physical Science.