- University of Toronto researchers have developed a stretchy, transparent and self-powering sensor that records the sensations of human skin
- It consists of a layer of hydrogel that can convert mechanical stimuli and humidity into variable resistance and capacitance
The need for efficient sensors that can measure humidity and temperature is increasing day by day. The medical sector is seeking solutions that can provide sensing data without the use of power sources.
The University of Toronto has claimed that they have found a solution for battery-free temperature and moisture sensing. The researchers told that they have developed a stretchy and transparent sensor that can sense and record the sensations in human skin. The device is said to be self-powered and does not require any power source to work.
The self-generating power can be measured as an open-circuit voltage or short-circuit current. The device is made up of hydrogels. More than 90 per cent of structural hydrogel consists of water content. The developed sensor is a ‘double-network’ hydrogel. It is formed by mixing two different hydrogels. It consists of a stiff and soft hydrogel.
Coined as ‘AI-Skin’
Double-network hydrogels are a known route to highly flexible materials. These materials are generally strong and tough. The team of researchers, in an experiment, provided the two hydrogels with opposite ionic charges. As a result, a sensing junction created at the gel’s surface. This developed gel is coined as ‘ AI-Skin’.
Inexpensive and biocompatible
According to the researchers, AI-Skin is inexpensive and biocompatible. The material also shows high adhesive properties. This property helps in sturdy placement of the sensor in human skin. When the AI-Skin senses humidity or changes in temperature, it generates ion movements across the sensing junction. These electric signal can be measured as changes in voltage or current.
Liu, Researcher for AI-Skin, told about the new innovation saying,
“If you look at human skin, how we sense heat or pressure, our neural cells transmit information through ions – it’s really not so different from our artificial skin. For muscle rehabilitation “if you were to put this material on a glove of a patient rehabilitating their hand, for example, the health care workers would be able to monitor their finger-bending movements.”
Works over a wide humidity sensing range
The hydrogel is stretchable for up to 400 per cent of its original size. The sensor can work in relative humidities ranging between 13 and 85 per cent. It and has been demonstrated as a wearable strain-humidity sensor. It is helpful in human-machine interactions. Additionally, in general purposes, it can be utilised as a walking energy harvester.
Primary applications such as smart bandages
The AI-Skin can be utilised in a number of applications associated with wearable electronics, personal health care and robotics. Robotic hands could be lined with the material to sense the temperature or pressure on the gripped objects. The researchers are seeking its applications into a smart bandage. As it is a water-based hydrogel, it can regulate moisture content that is necessary for wound healing.