E-skin becomes wireless, without chips and batteries

Less than 20 years ago for robotics, today’s e-skin has evolved and gone wireless, paving the way for a new generation of wearable technologies beneficial to health and sports. Results, published In Science, it’s due to researchers from the Massachusetts Institute of Technology (MIT), who have developed an ‘electronic skin’ capable of detecting and transmitting signals related to pulses, sweats, and UV exposure without the use of Bluetooth communication chips and no bulky batteries.

The new e-skin is a flexible semiconductor film that sticks to the skin like a patch. The ‘core’ of the sensor is a very thin layer of gallium nitride, a material known for its piezoelectric properties (it can produce an electrical signal in response to mechanical deformation, and conversely, it can vibrate mechanically in response to an electrical pulse). Specifically, the researchers produced samples of pure gallium nitride and attached them to a conductive layer of gold to enhance the electrical input and output signals. They then explained that the device is sensitive enough to vibrate in response to heartbeats and salts in sweat: the material’s vibration then generates electrical signals that can be read by a nearby receiver. This “electronic skin” “can be placed on the body like a bandage and, combined with a wireless reader on a smartphone, allows you to monitor heart rate, sweating and other biological signals,” notes MIT engineer Jeehwan Kim.

This scenario may still sound like science fiction in the 1980s, when the first search for e-skin began, and perhaps even in the early 2000s, when the prototypes formed. The first fully flexible electronic skin capable of perceiving pressure and temperature dates back to 2005: it was developed at the University of Tokyo, and contained a dual network of sensors to give the automata a similar sense of touch. Only three years later, at the University of Illinois, an electronic adhesive skin was developed, which was applied to the skin like a tattoo, and was able to restore the tactile sensations of those who had lost them or monitor parameters such as those related to the work of the heart. Driven by growing environmental awareness, in 2018, it reached the first fully recyclable e-leather fix itselfLike a Terminator and rubber like a human.

Soon, the e-skin was able to feel hot, cold and wet: the tipping point for touch for robots but also for prosthetics. In 2020, the first electronic skin that senses pain It reacts almost instantaneously, just as our natural skin does: Useful for robotics and prosthetics, it is a candidate to become a high-tech alternative to implantable skin grafts. Finally, in 2021, MIT researchers developed the first e-skin with pores, able to adhere better to the human body to detect agents even when you sweat during sports.