Canadian scientists have designed and fabricated a very-stretchy, transparent and self-powering type of sensor that can measure the sensations of human skin. The sensor has been named ‘artificial ionic skin ‘ (AISkin). The aim is to help advance robotics as well as the next generation of wearable electronics and medical technology.
The snesor is a form of adhesive material fashioned from two oppositely charged sheets of hydrogels (which have stretchable properties). When the negative and positive sheets are laid across each other this generates a “sensing junction” across the gel’s surface.
As the AISkin is subjected to strain, or climatic changes like humidity or variations with the surrounding temperature, this generates a specific pattern of ion movements which traverse across the sensing junction. The ion movement is assessed by measuring electrical signals, like variations with voltage or current.
In a sense this is not very different from human skin, which senses pressure and temperature through ions gravitating within neurons.
According to lead researcher Professor Xinyu Liu, of the University of Toronto: “Since it’s hydrogel, it’s inexpensive and biocompatible — you can put it on the skin without any toxic effects. It’s also very adhesive, and it doesn’t fall off, so there are so many avenues for this material.”
A further advantage with the artificial skin is its relative strength and the fact that it can be stretched a relatively long way, up to 50 times the original size and still continue to retain the sensing capabilities imparted by the research team. A useful application will be in the field of soft robotics; these are flexible machines composed completely out of polymers and used to survey things like pipes or used to monitor more extreme environments.
The research has been published in the journal Materials Horizon. The paper is titled “An ambient-stable and stretchable ionic skin with multimodal sensation.”
