From Science Fiction to Reality: A Bionic Finger Could Replace X-rays for Medical Imaging

A team of researchers has created a bionic finger that is capable of emulating the sensory capabilities of a human finger. This innovative device can precisely map and detect any object or surface it comes into contact with, providing a remarkable level of accuracy and detail in its sensing function. For many years, medical technologies such as X-rays, MRI, and ultrasound have been the go-to methods for examining the human body. However, these methods are not without their drawbacks. X-rays, in particular, carry the risk of cancer with even a slight increase in exposure. Meanwhile, MRI can cause a range of side effects due to the use of magnetic imaging. Despite their benefits, these technologies have yet to be replaced with a safer alternative.

Imagine being able to create detailed images of the insides of human bodies and electronic devices using just the sense of touch. This possibility has now become a reality, thanks to the groundbreaking work of researchers at Wuyi University. They have developed a bionic finger that can generate 3D maps of complex objects' internal shapes and textures by touching their outer surface. The device was inspired by the incredible sensory capabilities of the human finger, which can not only detect the texture of our skin but also discern the outline of the bone beneath it.

The bionic finger utilizes a "scanning" method by moving across the object and applying pressure, much like a continuous series of pokes or prods. Each poke causes the carbon fibers within the device to compress, providing valuable information about the object's stiffness or softness. Depending on the object's material, it may also deform under pressure from the bionic finger. Rigid objects maintain their shape, while soft ones will bend or give way. This information, along with its corresponding location, is then transmitted to a personal computer where it is processed and displayed as a 3D map.

To assess its capability of mapping the internal and external characteristics of complex objects composed of multiple materials, the bionic finger underwent rigorous testing. Researchers chose to scan a small, compound object comprised of three distinct materials: a rigid internal material, a soft internal material, and a soft outer coating. The bionic finger was able to successfully differentiate between the soft outer coating and the internal hard ridges, demonstrating its ability to discriminate between different materials.

Continuing their development efforts, the researchers decided to assess the bionic finger's ability to replicate human tissue sensing. To achieve this, they created a synthetic tissue using 3D printing technology, which included a skeletal component made of three layers of hard polymer and a soft silicone "muscle" layer. The bionic finger successfully generated a 3D profile of the tissue's structure and was able to locate a simulated blood vessel beneath the muscle layer, demonstrating its impressive capacity to sense and map out internal components of the human body.

The researchers have outlined their plans to expand the bionic finger's capabilities to include omnidirectional detection. This development will pave the way for a non-optical and non-destructive method of testing both the human body and flexible electronics. With this upgrade, the bionic finger will be able to detect and map objects from all angles, thereby enabling a more comprehensive and detailed analysis of complex structures.

Reference : Jianyi Luo & colleauges, A smart bionic finger for subsurface tactile-tomography, Cell Reports Physical Science (2023).