Article

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: 10.74). 11/2011; 2:527. DOI: 10.1038/ncomms1531
Source: PubMed

ABSTRACT 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.

1 Follower
 · 
92 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cracks are observed in many environments, including walls, dried wood and even the Earth's crust, and are often thought of as an unavoidable, unwanted phenomenon. Recent research advances have demonstrated the the ability to use cracks to produce various micro and nanoscale patterns. However, patterns are usually limited by the chosen substrate material and the applied tensile stresses. Here we describe an innovative cracking-assisted nanofabrication technique that relies only on a standard photolithography process. This novel technique produces well-controlled nanopatterns in any desired shape and in a variety of geometric dimensions, over large areas and with a high throughput. In addition, we show that mixed-scale patterns fabricated using the 'crack-photolithography' technique can be used as master moulds for replicating numerous nanofluidic devices via soft lithography, which to the best of our knowledge is a technique that has not been reported in previous studies on materials' mechanical failure, including cracking.
    Nature Communications 02/2015; 6:6247. DOI:10.1038/ncomms7247 · 10.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigate the finite bending of a bilayer gel in response to temperature under plane strain condition. We demonstrate that our model based on finite elasticity predicts larger bending curvatures of the bilayers compared with the linear model based on the elementary beam theory, and a high swelling ratio in the bilayer enhances the differences between both models. We also show that the folding shape of the bilayer can be controlled by tuning the ratio of shear modulus and the length-to-height ratio and that multiple neutral axes can exist in the bilayer under certain conditions. Our results could provide the basis for further numerical modeling of a layered gel as well as a spatially patterned gel to create 3D complex self-folding structures.
    International Journal of Solids and Structures 12/2014; DOI:10.1016/j.ijsolstr.2014.12.009 · 2.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A free-standing nanofiber membrane can be simultaneously fabricated, patterned, and integrated with electrolyte-assisted electrospinning (ELES). The fluidic nature of the electrolyte collector enables flexible patterning and facile integration of the free-standing nanofiber membrane on complex substrates from a 2D flat surface to a 3D curved geometry via ELES. The structural integrity and performance of the free-standing nanofiber membrane are verified, and this plays a crucial role for future applications, including organ-on-a-chip, tissue scaffolds, and biosensors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
    Advanced Materials 01/2015; 27(10). DOI:10.1002/adma.201404741 · 15.41 Impact Factor