title: Synthesis of colloidal microgels using oxygen-controlled flow lithography.
abstract: We report a synthesis approach based on stop-flow lithography (SFL) for fabricating colloidal microparticles with any arbitrary 2D-extruded shape. By modulating the degree of oxygen inhibition during synthesis, we achieved previously unattainable particle sizes. Brownian diffusion of colloidal discs in bulk suggests the out-of-plane dimension can be as small as 0.8 μm, which agrees with confocal microscopy measurements. We measured the hindered diffusion of microdiscs near a solid surface and compared our results to theoretical predictions. These colloidal particles can also flow through physiological microvascular networks formed by endothelial cells undergoing vasculogensis under minimal hydrostatic pressure (∼5 mm H2O). This versatile platform creates future opportunities for on-chip parametric studies of particle geometry effects on particle passage properties, distribution and cellular interactions.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. pdoyle@mit.edu.
authors.forename: Harry Z
authors.initials: HZ
authors.lastname: An
authors.forename: H Burak
authors.initials: HB
authors.lastname: Eral
authors.forename: Lynna
authors.initials: L
authors.lastname: Chen
authors.forename: Michelle B
authors.initials: MB
authors.lastname: Chen
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Doyle
mesh_terms: D003102:Colloids / Q000138:chemical synthesis* / Q000737:chemistry*; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D003102:Colloids; C437167:poly(ethylene glycol)diacrylate; D011092:Polyethylene Glycols; D010100:Oxygen