Continuous-flow lithography for high-throughput microparticle synthesis

Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Nature Materials (Impact Factor: 36.5). 06/2006; 5(5):365-9. DOI: 10.1038/nmat1617
Source: PubMed


Precisely shaped polymeric particles and structures are widely used for applications in photonic materials, MEMS, biomaterials and self-assembly. Current approaches for particle synthesis are either batch processes or flow-through microfluidic schemes that are based on two-phase systems, limiting the throughput, shape and functionality of the particles. We report a one-phase method that combines the advantages of microscope projection photolithography and microfluidics to continuously form morphologically complex or multifunctional particles down to the colloidal length scale. Exploiting the inhibition of free-radical polymerization near PDMS surfaces, we are able to repeatedly pattern and flow rows of particles in less than 0.1 s, affording a throughput of near 100 particles per second using the simplest of device designs. Polymerization was also carried out across laminar, co-flowing streams to generate Janus particles containing different chemistries, whose relative proportions could be easily tuned. This new high-throughput technique offers unprecedented control over particle size, shape and anisotropy.

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Available from: Daniel Pregibon, Jan 30, 2014
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    • ". Flow lithography is a photolithographic technique where a pattern is projected into a photocurable polymer to form particles (Fig. 4e). In continuous-flow lithography, shape-defined photopolymerized microparticles can be made by passing UV-light through a transparency mask that is projected using a standard microscope objective down into a microfluidic device filled with monomer and photoinitiator [69]. "
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