Graduate students Mingzhu Liu and Veronica Grebe use regioselective depletion interactions to introduce directional bonding and direct the assemble anisotropic biphasic colloids. By changing the depletion conditions, the assembly of a binary colloidal mixture can be tuned. Combining these materials as triblock biphasic colloids yields particles of various aspect ratios that can similarly be tuned by depletion conditions. The particle assemble into various colloidal superlattices and superstructures with optimized center-to-center or pole-to-pole interactions, dependent on the aspect ratio. Polymorphic crystallization is observed and quantified using algorithms developed. The work contributes selective control of regional attractive interactions, precluding the need for surface treatment and functionalization. Check out the article here.