These glowing capsules shine in stressful situations—literally. Called polymersomes, the round, man-made membranes are studded with light-emitting pigments called porphyrins. When the membrane encounters stress, like tension or heat, the pigments change their configuration. Since shape determines how the porphyrins absorb and release light, the pigments glow in different hues. Here, the stressed region is evident before the membrane ruptures. Only a few microns in size, these miniscule mood rings could be used in body scanning or injected into the bloodstream to provide clues about nearby stresses, such as arterial blockages. Image courtesy of Neha Kamat, University of Pennsylvania. Read more... Link to external Website

Featured in the September 15, 2011, issue of Biomedical Beat.