The new electronic skin can react to pain like human skin

Researchers have developed electronic artificial skin that reacts to pain just like real skin, opening the way for better prosthetics, smarter robots, and non-invasive alternatives to skin grafts.

The model device developed by a team at RMIT University in Melbourne, Australia, could electronically replicate the way human skin feels pain.

The device mimics the body’s near-instantaneous reflex response and can react to painful sensations at the same speed as light as nerve signals travel to the brain.

Lead researcher, Professor Madhu Baskaran, said the prototype pain sensor was a major advance towards the next generation of biomedical technologies and smart robots.

“The skin is the largest sensory organ in our body, with complex features designed to send out quick warning signals when anything hurts,” Bhaskaran said.

“We feel things all the time through the skin, but our response to pain only begins at a certain point, such as when we touch something very hot or very sharp.

“There are no electronic technologies that can realistically simulate a person’s feeling of pain – yet.

Our faux leather reacts instantly when pressure, heat or cold reaches a painful threshold.

“It is a critical step forward in the future development of the sophisticated feedback systems we need to deliver truly intelligent prosthetics and intelligent robots.”

In addition to a prototype pain sensor, the research team has also developed devices that use expandable electronics that can sense and respond to changes in temperature and pressure.

The three prototypes were designed to present key features of skin-sensing ability in electronic form, said Baskaran, co-chair of RMIT’s Functional Materials and Microsystems Group.

With further development, stretchable artificial leather could also be a future option for non-invasive skin grafts, where the traditional approach is either not applicable or does not work.

“We need more development to integrate this technology into biomedical applications, but the fundamentals – biocompatibility, skin-like stretching – are already in place,” Bhaskaran said.

New research published in Advanced smart systems Registered as a provisional patent, it combines three technologies that were previously pioneered and patented by the team:

• Stretchable Electronics: Combine bio-compatible oxide and silicone to deliver clear, unbreakable, wearable electronics with the same thinness as a label.
• Temperature Reactive Coatings: Self-modifying coatings are 1,000 times thinner than a human hair based on a substance that transforms in response to heat.
• Brain simulation memory: electronic memory cells that simulate the way the brain uses long-term memory to retrieve and retain previous information.

The prototype pressure sensor combines stretchable electronics with long-term memory cells, the heat sensor combines temperature-reactive coatings and memory, while the pain sensor integrates all three technologies.

PhD researcher Md Ataur Rahman said the memory cells in each prototype were responsible for eliciting a response when pressure, heat, or pain reached a specific threshold.

“We basically created the first electronic physical sensors – to replicate key features of the body’s complex system of neurons, nerve pathways and receptors that drive our perception of sensory stimuli,” he said.

“While some current technologies use electrical signals to mimic different levels of pain, these new devices can react to real mechanical pressure, temperature and pain, and provide the correct electronic response.

“This means that our artificial leather knows the difference between gently touching a pin with your finger or accidentally stabbing yourself with it – a critical distinction never before achieved electronically.”

The research was supported by the Australian Research Council and conducted at RMIT’s state-of-the-art Micro Nano Research Facility for micro / nanoscale fabrication and device modeling.

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“Synthetic somatic sensors: e-skin feedback receptors”, in collaboration with the National Institute of Cardiovascular Diseases (Bangladesh), have been published in Advanced smart systems (DOI: 10.1002 / aisy.202000094).