Bandage Changes Color to Indicate State of Wound Underneath

Researchers in Germany have created bandages that turn purple at the first sign of infection.

A new wound dressing, developed at the Fraunhofer Research Institution for Modular Solid State Technologies EMFT in Munich, includes a special dye that reacts to different pH values.

The new trauma bandage insulates wounds just like any other bandage, but it provides a special window into how a wound is healing. Typically, healthy skin and healed wounds have a slightly acidic pH, around 5 or 6. If this value increases into the alkaline range, that can indicate infection, reports Gizmag.

If the pH value is between 6.5 and 8.5, the new bandage will turn purple, according to Dr. Sabine Trupp, a scientist at the EMFT. The indicator strip can allow patients and doctors to monitor for infection without having to change dressings. This is an advantage because removing a bandage can let in germs. The next step is to test the strips at a German hospital’s dermatology clinic.

Eventually, the researchers want to integrate an optical sensor, which could measure pH values and indicate the results on a screen, providing precise data about whether a wound is getting better.