During the last decade significant advances in controlling nano objects and polymer/DNA clusters with optical traps have been demonstrated along with the ability to create various phase changes induced by photon pressure.
Here we present a novel method were colloidal particles with controlled size are created when an optical trap is introduced while an emulsion or micro-emulsion polymerization is taking place. Nucleation seeds, oligomers and micelles are attracted to the trap and (under certain parameters) coalesce and polymerize, thus creating a colloidal particle.
To create numerous colloids the optical trap is focused within a microfluidic channel. The size of the forming colloids is determined by the intensity of the laser and the flow rate of the solution. Using Holographic Optical Tweezers (HOT) we create hundreds of traps that are independently controlled and therefor create any kind of colloidal size combination.
The versatility and ease of making various changes to the end product without the need for chemical modifications makes this approach appealing for testing model systems.
hagay.shpaisman@biu.ac.il
