After six years of hard work, an Italian researcher has managed to create state-of-the-art smart skin that is more sensitive than real skin and can even detect microorganisms.
Working at the Institute of Solid State Physics at the Technical University of Graz (TU Graz) in Austria, Anna Maria Coclite has revealed her pioneering development of a three-in-one “smart skin” hybrid material that can detect touch, temperature and humidity.
Coclite and his team worked on developing smart skin as part of their European Research Council (ERC) Smart Core project. With 2,000 individual sensors per square millimeter, the hybrid material is even more sensitive than a human fingertip.
Each of the sensors consists of a unique combination of materials: an intelligent polymer in the form of a hydrogel inside and a piezoelectric zinc oxide housing.
Coclite explains: “The hydrogel can absorb water and thus expand with changes in humidity and temperature. In doing so, it exerts pressure on the piezoelectric zinc oxide, which responds to this and all other mechanical stresses with a electrical signal”. The result is a thin material that simultaneously reacts to force, humidity and temperature with extremely high spatial resolution and emits corresponding electronic signals.”
The skin is the largest sensory organ and at the same time acts as the protective layer of the human being.
It “feels” multiple sensory inputs simultaneously and reports information about humidity, temperature and pressure to the brain. For Coclite, a material with such multisensory properties is “a kind of ‘holy grail’ in intelligent artificial materials technology.”
She said: “In particular, robotics and smart prosthetics would benefit from a more integrated and accurate detection system, similar to human skin.”
ERC Fellow and Researcher at the Institute of Solid State Physics at TU Graz, Coclite has published her pioneering research in the journal Advanced Materials Technologies.
She said: “The first samples of artificial skin are six micrometers thick, or 0.006 millimeters. But it could be even thinner.”
In comparison, the human epidermis is 0.03 to 2 millimeters thick.
Human skin perceives things to a size of about 1 square millimeter. The smart skin has a thousand times lower resolution and can register objects too small for human skin, such as microorganisms.
The individual sensor layers are very thin and at the same time equipped with sensor elements that cover the entire surface.
This was made possible in a unique worldwide process for which the researchers combined three methods known from physical chemistry for the first time: a chemical vapor deposition for the hydrogel material, an atomic layer deposition for the zinc oxide and nanoprint lithography for polymer model.
The lithographic preparation of the polymeric mold was in charge of the research group “Hybrid electronics and structuring” led by Barbara Stadlober. The group is part of the Joanneum Research Materials Institute, based in Weiz, Austria.
Various fields of application are opening up for the skin-like hybrid material.
In healthcare, for example, sensor material can independently detect microorganisms and report them accordingly. Also conceivable are prostheses that provide the user with information about temperature or humidity, or robots that can perceive their environment more sensitively.
On the way to application, smart skin scores with a decisive advantage: the sensory nanorods – the “smart core” of the material – are produced using a steam-based manufacturing process. This process is already well established in integrated circuit production plants, for example. Smart skin production can thus be easily scaled up and implemented in existing production lines.
Smart skin properties are being further optimized. Coclite and his team – in particular Ph.D. student Taher Abu Ali – want to expand the temperature range to which the material reacts and improve the flexibility of the artificial skin.
This story was provided to Newsweek by Zenger News.