In a method for synthesizing polymeric microstructures, a monomer stream is flowed, at a selected flow rate, through a fluidic channel. At least one shaped pulse of illumination is projected to the monomer stream, defining in the monomer stream a shape of at least one microstructure corresponding to the illumination pulse shape while polymerizing that microstructure shape in the monomer stream by the illumination pulse. An article of manufacture includes a non-spheroidal polymeric microstructure that has a plurality of distinct material regions.