Recent breakthroughs in particle synthesis leading to nanoscopic and colloidal particles of unusual shape and patterning have paved the way for a revolution in materials formed from the self-assembly of these building blocks. The unprecedented anisotropy of today's new particulate building blocks starkly contrasts with the isotropic, spherical colloids that have been the focus of particle assembly for more than a generation. As the materials community gains further control over the design and fabrication of these new particles, they are poised to become the “atoms” and “molecules” of tomorrow's materials and devices, provided we can learn to assemble them into predictable and useful structures.

Fundamentally, no comprehensive theory exists to predict the range of structures possible for these new building blocks as a function of thermodynamic conditions, and the complementary problem of inverse design of a particular building block that can self-assemble into a desired target structure is difficult with as yet no standard design algorithm. In this talk, we discuss the need for a conceptual framework and common language with which to describe these new building blocks and their assemblies. We discuss the concept of "anisotropy dimensions" and show how various measures of anisotropy, including particle shape, patterning, functionalization and interaction selectivity, can be combined and exploited to achieve complex mesoscale one-, two- and three-dimensional structures through self-assembly[1].

[1] S.C. Glotzer and M.J. Solomon, The shape revolution: anisotropy and assembly of new building blocks, Nature Materials, in press.