Macroscopic Self-Assembly of Binary Crystals
Formed by Vigorous Shaking in a Music SLAM

Whitesides and Weitz are investigating the remarkable macroscopic self-assembly of large particles. By shaking a binary mixture of two different types of particles, they induced charges on the particles through tribocharging. The particles start in a random, disordered structure as shown in the left figure. After shaking the particles for several minutes, order begins to arise in the particles as they are shaken. Eventually they adapt a crystalline ordering of a binary two-dimensional crystal, as shown in the right figure. Remarkably, they retain this compact, ordered structure despite being vigorously shaken. This represents a new approach to creating macroscopic self-assembled structures. Graduate student Sarah Battat set this whole process to the music of Michael Jackson's Beat It with original lyrics in her MRSEC SLAM.

Article:
First-ever NSF-MRSEC Science Slam