Engineers at the University of California, Berkeley and UC San Francisco have created a new smart bandage that uses electrical currents to detect early tissue damage from pressure ulcers, or bed sores, before they can be seen by human eyes – and while recovery is still possible. The researchers exploited the electrical changes that occur when a healthy cell starts dying. They tested the thin, non-invasive bandage on the skin of rats and found that the device was able to detect varying degrees of tissue damage consistently across multiple animals. The smart bandage is fabricated by printing gold electrodes onto a thin piece of plastic. This flexible sensor uses impedance spectroscopy to detect bedsores that are invisible to the naked eye.