Differentially photo-crosslinked polymers enable self-assembling microfluidics

Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA.
Nature Communications (Impact Factor: 11.47). 11/2011; 2(1):527. DOI: 10.1038/ncomms1531
Source: PubMed


An important feature of naturally self-assembled systems such as leaves and tissues is that they are curved and have embedded fluidic channels that enable the transport of nutrients to, or removal of waste from, specific three-dimensional regions. Here we report the self-assembly of photopatterned polymers, and consequently microfluidic devices, into curved geometries. We discover that differentially photo-crosslinked SU-8 films spontaneously and reversibly curve on film de-solvation and re-solvation. Photolithographic patterning of the SU-8 films enables the self-assembly of cylinders, cubes and bidirectionally folded sheets. We integrate polydimethylsiloxane microfluidic channels with these SU-8 films to self-assemble curved microfluidic networks.

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    • "Fabrication of well-ordered soft-matter-based micro and nano structures over large area has drawn great interests in recent years due to their increasing applicability in polymer electronics1, soft machines2, flash memory, chemical and biosensors345, particularly biological applications such as tissue-engineering6, surface modification78 and microfluidics9. Owing to the importance associated with the soft-matter-based micro and nano structures, numerous conventional experimental methods have been developed to date to fabricate the pattern of functional soft-matters, such as photolithography10, inkjet printing11, direct-laser writing12, dip-pen and polymer pen lithography131415. Although these techniques are mature for use in microelectronics and contributed important roles in modern digital life for the high density of integration, less power consumption and good performances, they do have some limitations, such as high operational costs from the high-priced equipment and clean room demanding processes, incompatibility with curved surfaces, poor suitability for three-dimensional (3D) fabrication, little or no control over surface chemistry and exclusive application in the direct patterning of a limited set of functional materials16. "
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