Materials scientists are constantly trying to tweak their products to be a little stronger, a little less brittle, a little more malleable--it's the engineer's job to imbue any material with the properties it needs to do its job. That often means striking a compromise between conflicting properties, but perhaps not for much longer. Researchers at the Technical University of Hamburg and the Helmholtz Center Geesthacht have engineered a new nanomaterial that changes from hard to soft with the flip of a switch.