Researchers have developed a new type of wearable sensor that can mimic the sensing properties of skin, an advance that could someday lead to artificial skin that helps burn victims 'feel'.

Our skin's ability to perceive pressure, heat, cold and vibration is a critical safety function that most people take for granted. But burn victims, those with prosthetic limbs and others who have lost skin sensitivity for one reason or another, can't take it for granted and often injure themselves unintentionally.

The new sensor is built with iron oxide nanoparticles in silicone and shows promise as a skin replacement material. Besides helping burn victims, it can also safeguard people exposed to dangerously high magnetic fields, and alert parents if their child falls into deep water in a pool.

"It would be very cool if it (the sensor) had abilities human skin does not; for example, the ability to detect magnetic fields, sound waves and abnormal behaviour," said Islam Mosa, a chemist from the University of Connecticut and a part of the research team.

The new sensor, detailed in the journal Advanced Materials, is built with a silicone tube wrapped in a copper wire and filled with a special fluid made of tiny particles of iron oxide just one billionth of a meter long, called nanoparticles. 

The nanoparticles rub around the inside of the silicone tube and create an electric current. The copper wire surrounding the silicone tube picks up the current as a signal. When this tube is bumped by something experiencing pressure, the nanoparticles move and the electric signal changes. 

Sound waves also create waves in the nanoparticle fluid, and the electric signal changes in a different way than when the tube is bumped. The researchers found that magnetic fields alter the signal, too. Even a person moving around while carrying the sensor changes the electrical current, and the team found they could distinguish between the electrical signals caused by walking, running, jumping and swimming.

The researchers hope it could help burn victims "feel" again, and perhaps act as an early warning for workers exposed to dangerously high magnetic fields. Because the rubber exterior is completely sealed and waterproof, it could also serve as a wearable monitor to alert parents if their child falls into deep water in a pool.