Abstract
Precisely shaped polymeric particles and structures are widely used for applications in photonic materials1, MEMS2, biomaterials3 and self-assembly4. Current approaches for particle synthesis are either batch processes5,6,7,8,9,10 or flow-through microfluidic schemes11,12,13,14,15,16 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 photolithography7 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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Acknowledgements
We gratefully acknowledge the support of NSF NIRT Grant No. CTS-0304128 for this project. We thank Y. Hu for assistance with fluorescence microscopy, as well as K. Krogman and J. Lutkenhaus for assistance with FTIR measurements.
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Dendukuri, D., Pregibon, D., Collins, J. et al. Continuous-flow lithography for high-throughput microparticle synthesis. Nature Mater 5, 365–369 (2006). https://doi.org/10.1038/nmat1617
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DOI: https://doi.org/10.1038/nmat1617
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