Sep 2 2020
Scientists have designed a novel electronic artificial skin that responds to pain in a similar way to real skin. This latest breakthrough can pave the way to smarter robotics, better prosthetics, and non-invasive alternatives to skin grafts.
The skin-like sensing prototype device, made with stretchable electronics. Image Credit: RMIT University.
A research team from RMIT University developed the prototype device that can electronically simulate the way the human skin perceives pain.
The novel device imitates the near-instant feedback reaction of the body and can rapidly respond to painful sensations, that is, the same speed at which nerve signals reach the brain.
According to lead researcher and Professor Madhu Bhaskaran, the pain-sensing device represents a major advancement towards smart robotics and state-of-the-art biomedical technologies.
Skin is our body’s largest sensory organ, with complex features designed to send rapid-fire warning signals when anything hurts. We’re sensing things all the time through the skin but our pain response only kicks in at a certain point, like when we touch something too hot or too sharp.
Madhu Bhaskaran, Lead Researcher and Professor, RMIT University
Bhaskaran continued, “No electronic technologies have been able to realistically mimic that very human feeling of pain—until now. Our artificial skin reacts instantly when pressure, heat or cold reach a painful threshold. It’s a critical step forward in the future development of the sophisticated feedback systems that we need to deliver truly smart prosthetics and intelligent robotics.”
Functional Sensing Prototypes
In addition to the pain-sensing prototype, the researchers have also designed devices with the help of stretchable electronics. These electronics are capable of sensing and reacting to variations in pressure and temperature.
Bhaskaran, who is also the co-leader of the Functional Materials and Microsystems group at RMIT University, added that the three functional models were developed to provide crucial features of the skin’s sensing potential in electronic form.
With additional advancement, the new, stretchable artificial skin could also serve as a future option for non-invasive skin grafts, in which the conventional method is either not working or not feasible.
We need further development to integrate this technology into biomedical applications but the fundamentals–biocompatibility, skin-like stretchability–are already there.
Madhu Bhaskaran, Lead Researcher and Professor, RMIT University
How to Make Electronic Skin
The new study integrates three technologies that were already pioneered and patented by the researchers. The study has been published in the Advanced Intelligent Systems journal and filed as a provisional patent.
- Stretchable electronics—by integrating biocompatible silicone with oxide materials, these electronics offer wearable, unbreakable, and transparent electronics that are as thin as a sticker.
- Temperature-reactive coatings—based on a material that converts in response to heat, these self-modifying coatings are 1000 times thinner than a single strand of human hair.
- Brain-mimicking memory—electronic memory cells that mimic the way long-term memory is used by the brain to recollect and retain earlier information.
The heat sensor brings the memory and temperature-reactive coatings together; the pressure sensor model integrates long-term memory cells and stretchable electronics; the pain sensor incorporates all the three technologies.
Md Ataur Rahman, a PhD researcher, stated that the memory cells in every prototype account for initiating a reaction as soon as the pain, heat, or pressure reaches a set threshold.
We’ve essentially created the first electronic somatosensors–replicating the key features of the body’s complex system of neurons, neural pathways and receptors that drive our perception of sensory stimuli.
Md Ataur Rahman, PhD Researcher, RMIT University
Rahman continued, “While some existing technologies have used electrical signals to mimic different levels of pain, these new devices can react to real mechanical pressure, temperature and pain, and deliver the right electronic response.”
“It means our artificial skin knows the difference between gently touching a pin with your finger or accidentally stabbing yourself with it–a critical distinction that has never been achieved before electronically,” Rahman further added.
The study was financially supported by the Australian Research Council and undertaken at RMIT University’s advanced Micro Nano Research Facility dedicated to device prototyping and micro/nano-fabrication.
Journal Reference:
Rahman, M. A., et al. (2020) Artificial Somatosensors: Feedback Receptors for Electronic Skins. Advanced Intelligent Systems. doi.org/10.1002/aisy.202000094.