Piezoelectric Paint in Finland
Pressure-sensitive paint will warn when a bridge is about to collapse. VTT Technical Research
Centre in Helsinki, Finland, added piezoelectric crystals, which produce a voltage when stressed, to a resin which was painted on the underside of a steel footbridge (Smart Materials and Structures, vol 16, p 2571). Electrodes at each end of the bridge detected changes in voltage as people crossed the bridge. The crystals can be used to detect pressure changes due to structural flaws.