A GIANT PIEZOELECTRIC EFFECT has been observed in strontium titanate at low temperatures. The piezoelectric process, by which mechanical energy in a crystal is converted into electricity (and vice versa), generally gets worse below 50 K, but in the case of SrTiO₃, it gets better. At 1.6 K, in fact, STO competes with the best room-temperature piezoelectrics. The ultralow-temperature manifestation of this effect might result in new forms of microscopy or thermometry. (Science, 18 April 1997.)