Lock and key colloids through polymerization-induced buckling of monodisperse silicon oil droplets

We have developed a new simple method to fabricate bulk amounts of colloidal spheres with well defined cavities from monodisperse emulsions. Herein, we describe the formation mechanism of ‘‘reactive’’ silicon oil droplets that deform to reproducible shapes via a polymerization-induced buckling instability. Owing to their unique shape, the resulting particles can be successfully used as colloidal building blocks in the assembly of composite clusters via ‘‘lock-andkey’’ interactions.