A prototype device was developed that can electronically replicate the way human skin senses pain. The device mimics the body's near-instant feedback response and can react to painful sensations with the same speed that nerve signals travel to the brain. The artificial skin reacts instantly when pressure, heat, or cold reach a painful threshold.
As well as the pain-sensing prototype, the research team has also developed devices made with stretchable electronics that can sense and respond to changes in temperature and pressure. Three functional prototypes were designed to deliver key features of the skin's sensing capability in electronic form. With further development, the stretchable artificial skin could also be a future option for non-invasive skin grafts, where the traditional approach is not viable or not working.
The prototype combines three technologies:
- Stretchable electronics combine oxide materials with biocompatible silicone to deliver transparent, unbreakable, and wearable electronics as thin as a sticker.
- Temperature-reactive coatings that are 1,000 times thinner than a human hair based on a material that transforms in response to heat.
- Brain-mimicking electronic memory cells imitate the way the brain uses long-term memory to recall and retain previous information.
The pressure sensor prototype combines stretchable electronics and long-term memory cells, the heat sensor brings together temperature-reactive coatings and memory, while the pain sensor integrates all three technologies. The sensors are somatosensors — replicating the key features of the body's complex system of neurons, neural pathways, and receptors that drive human perception of sensory stimuli.
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. As a result, the artificial skin knows the difference between gently touching a pin with your finger or accidentally stabbing yourself with it.