Cracking Crystallization: Self-assembly of Photonic Crystals by Controlling the Nucleation and Growth of DNA-Coated Colloids

Abstract:
Assembling optical metamaterials from DNA-coated colloids has been a central goal of programmable self-assembly for decades. Despite significant advances in expanding the structural diversity of colloidal crystals, a lack of understanding of the dynamic crystallization pathways has hindered the realization of programmable metamaterials. In this talk, I will describe how we combine experiments and theory to develop a complete understanding of the crystallization dynamics of DNA-coated colloids. Specifically, I will show that the nucleation and growth kinetics of DNA-coated colloids are fundamentally different from those of atoms or small molecules, owing to an effective friction that arises from transient DNA hybridization. By incorporating this effective friction into classical theories, such as classical nucleation theory, we can predict the absolute rates of nucleation and crystal growth with quantitative accuracy. I will conclude by showing how we use this quantitative picture of the crystallization dynamics to design new non-equilibrium protocols for making macroscopic photonic crystals that contain tens of millions of particles and can even be seen by the naked eye. Taken together, these experiments constitute one of the most well-controlled studies of nucleation and growth to date, and represent a key development in the creation of next-generation optical metamaterials from colloids.

Biography: 
Ben joined the Martin A. Fisher School of Physics at Brandeis University as an Assistant Professor in January 2016. His research program is focused on developing quantitative tools for understanding and controlling self-assembly at the nano- and micrometer scale. Before coming to Brandeis, Ben was a postdoctoral fellow in the Manoharan Lab within the School of Engineering and Applied Sciences at Harvard University, where he studied assembly and optical properties of colloidal suspensions. He received his Ph.D. in Chemical and Biomolecular Engineering from the University of Pennsylvania in 2012. With John Crocker, Ben used optical tweezers to study colloidal interactions and single-molecule kinetics. Ben graduated magna cum laude in 2005 from the University of Delaware, earning an Honors Bachelor of Chemical Engineering, with Distinction.