A skin crafted from two layers of electrodes around an ion-infused sponge is better at sensing than human skin because it can detect nearby objects and what they are made of
25 January 2023
An artificial skin is even better than human skin at sensing objects, because it can detect and identify items that it hasn’t touched yet.
“Human skin has to touch something to tell it what is there,” says Yifan Wang at Nanyang Technological University in Singapore. “Human skin can only tell the softness or hardness of an object. We wanted our artificial skin to have more functions.”
Even without touching an object, Wang and his colleagues’ artificial skin can sense if it is close by and can also discern some clues about the type of material it is made of. “We can tell whether it’s a piece of metal, plastic… or some biological material,” he says.
The skin is made up of two outer layers of conductive fabric coated with nickel to serve as electrodes. These surround a porous sponge soaked in ionic liquid, which is a salt in a liquid state that acts as a conduit for electricity. The two layers act as a capacitor, storing electrical energy in an electric field.
The ions in the sponge boost the performance of the capacitor, which effectively measures how much the distance between the two layers of electrodes changes. That ability to detect tiny shifts is behind how the artificial skin is able to detect that it has touched something.
The sensing performance of the capacitor, which Wang claims is between 10 and 100 times more sensitive than a standard capacitor, means it is also able to detect very small changes in the electric field around the skin, allowing it to sense when objects are near. What’s more, those subtle changes can help it identify what type of material a nearby object is made of.
In tests, the skin managed to detect and successful classify a series of objects brought near it as being either polymer, metal or skin, indicated by specific changes in the capacitor’s measurements.
“The process is relatively simple. As the component comes close to contact, it enters the edges of the electric field of the capacitive structure,” says Jonathan Aitken at the University of Sheffield, UK. “There are several interesting future routes,” he says, but at present the skin relies on machine learning techniques to identify how the object it detects compares with data on known materials.
Wang thinks the skin could work on a robotic finger to allow factory robots to better understand which objects to pick up and which to leave without having to grasp them, as well as being useful for prostheses.
More on these topics:
Source link Recent advances in technology have shone a light on the immense potential of artificial skin. Now, scientists have taken this concept to a revolutionary new level, enabling the artificial skin to detect nearby objects without even touching them.
Developed by researchers at the Technical University of Munich, the artificial skin is made of a highly sensitive and stretchable mater called graphene. This material is capable of detecting near-field objects and their distance. According to the scientists, the underlying principle behind the artificial skin is that objects close to the skin emit electrostatic field and potentials, which can be detected and measured by the graphene nanoparticles.
The artificial skin is unlike any other sensor-based system, as it can detect surrounding objects even when it is not in direct contact with them. This makes it ideal for scenarios where tactile contact would be dangerous or undesirable, such as underwater search and rescue missions, as well as contactless industrial inspection.
What’s more, the artificial skin is exceptionally accurate. It is capable of detecting objects accurately within a range of up to one millimeter, making it a highly versatile tool for many applications.
Due to its unique features, the artificial skin can be used in a diverse range of applications, from robotics to prosthetics – making it particularly valuable for aiding people with disabilities.
This groundbreaking development is just one example of the potential of this remarkable material. The possibilities of what can now be achieved with graphene look set to keep advancing, as scientists uncover its myriad of uses.