Ultra-Thin Hybrid Electronic Skin Is a Thousand Times More Sensitive Than the Tip of Your Finger
Easily mass-produced in existing chip fabs, this flexible skin packs thousands of sensors into an ultra-thin layer for extreme sensitivity.
A team of researchers at the Graz University of Technology and Joanneum Research's Institute for Surface Technologies and Photonics has developed a new hybrid material which, it is claimed, could give future robots and sensing systems smart human-like multisensory capabilities.
"[Multisensory materials are] a kind of 'holy grail' in the technology of intelligent artificial materials," explains Anna Maria Coclite, researcher at TU Graz' Institute of Solid State Physics and co-author of the paper revealing the work. "In particular, robotics and smart prosthetics would benefit from a better integrated, more precise sensing system similar to human skin."
The culmination of a six-year project, the hybrid material Coclite and colleagues have developed boasts 2,000 sensors per square millimeter — making it, they claim, more sensitive than the tip of your finger. Each sensor is made up of a smart polymer hydrogel and a piezoelectric zinc oxide shell. "The hydrogel can absorb water and thus expands upon changes in humidity and temperature," Coclite explains. "In doing so, it exerts pressure on the piezoelectric zinc oxide, which responds to this and all other mechanical stresses with an electrical signal."
Not only is the hybrid material potentially more sensitive than human skin, it's also thinner: The team's first samples are just six micrometers in thickness, or 0.006mm, while human skin varies from around 0.03mm to 2mm. Overall, the electronic skin is claimed to perceive objects up to a thousand times smaller than those detectable by human skin — down to the size, the team claims, of microorganisms.
A key part of the appeal to the team's material is that it is surprisingly easy to manufacture using a vapor-based process common to the integrated circuit manufacturing industry — meaning, the researchers claim, it should be easy and cost-effective to scale using existing production lines.
The team's work has been published in the journal Advanced Materials Technologies, and is accessible online under open early-access terms.