We report a simple and effective method to synthesize composite bowl-shaped colloidal particles composed of a magnetic bottom and polymer wall. The bowl-shape is determined by the stirring and the resulting centrifugal force acting on the components during the synthesis. By systematically varying the stirring speed, we have found the lower and upper bounds for the bowl formation. Moreover, the size and thickness of the bowl can be tuned by changing the amount of the TPM monomer during synthesis. Functional groups can be easily introduced in the solidifying step through the polymerization of TPM by adding initiators and functional monomers. For example, by copolymerization of glycomonomer with TPM, bowl-shaped particles with biological activity can be obtained. In addition, such composite particles can be further modified to produce micromotors with well-controlled motions.
