An iron-based artificial skin can sense the lightest touch.

Ahmed Alfadhel and Jürgen Kosel at the King Abdullah University of Science and Technology in Thuwal, Saudi Arabia, made a tactile sensor by embedding iron nanowires in hair-like structures called cilia, made of a polymer called polydimethylsiloxane, on a magnetic sensor. When the magnetized cilia are bent by touch, they trigger the sensor.

The skin can flex and, depending on the size of the cilia, can be sensitive enough to measure a person's wrist pulse. Because the cilia use permanent magnets rather than electromagnets, the device does not require much power and — unlike most other tactile sensors — it can work underwater and measure liquid flow, the authors say.

Adv. Mater. http://doi.org/f3jp2n (2015)