It sucks to get cut. It sucks even more (especially in the hospital) to continually remove a bandage and check for infections. Not only is this process annoying, but it can also increase the chance for infection. Crappy problem, awesome solution: a team of scientists at the Fraunhofer Research Institution for Modular Solid State Technologies in Munich have created a special dye that changes color at different pH's. Healthy skin has an acidic pH of 5 whereas infected skin has a pH in the alkaline range (pH>7). 

"If the pH value is between 6.5 and 8.5 an infection is frequently present and the indicator color strip turns purple," says Dr. Sabine Trupp, one of the lead scientists on the project. This provides an intelligent bandage material that can continuously check for infections without disrupting wound healing. 

What a smart bandage.