Julia Greer, professor of materials science, mechanics and medical engineering in Caltech’s Division of Engineering and Applied Science, creates materials out of micro- and nano-scale building blocks that are arranged into sophisticated architectures that can be periodic, like a lattice, or arbitrary. Described as “architected materials,” they sometimes exhibit unusual properties. For example, Greer has created ceramics with foam-like recoverability, lightweight but ultrastrong frames that can bounce back after compression, and mechanically robust batteries.