"Sensor, heal thyself," goes an old saying, and North Carolina State University researchers have given it a new spin. Structural stress monitors can break during, say, an earthquake or explosion: just when you most need information about a building's integrity. So the NCSU crew added a reservoir of ultraviolet-curable resin; if their sensor cracks, the resin flows into the gap, where a UV light hardens it. An infrared light, which does the actual monitoring, then has a complete circuit through which to pass, and voila: stress data flows once more, aiding decision-makers. Obviously we never tire of UV-reactive gadgetry, especially for making safer buildings, and we're doubly glad to see self-healing that doesn't involve the phrase "he's just not that into you." To see the self-repair in action, check the picture after the break, and hit the source link for more info.