Shaped particle fabrication methods by flow-lithography
from oldest
to newest. (a) Continuous flow lithography particles. The fabrication
system requires a computer-controlled shutter and continuous flowing
pumps. Scale bar is 30 μm. [Reprinted with permission from Macmillan
Publishers Ltd.: Nature, Dendukuri, D., et al. Nature Mater.2006, 5 (5), 365–369 (ref (10)) Copyright 2006.] (b)
Maskless lithography particles. The shutter is replaced with a dynamic
mask. Scale bar is 100 μm. [Reprinted with permission from ref (143). Anna, S. L., et al. Applied Physics Letters2003, 82 (3), 364–366 licensed under a Creative Common Attribution
(CC BY) license.] (c) Stop flow lithography particles. A computer-controlled
valve is introduced to control flow, resulting in higher resolution
particles. Scale bar is 30 μm. [Reproduced from Chung, S. E.,
et al. Applied Physics Letters2007, 91 (4), 041106 (ref (144)) with permission from The Royal Society of Chemistry.]
(d) Two-photon continuous lithography particles. This fabrication
system requires both a focused laser and a motorized stage. Scale
bar is 20 μm. [Reproduced from Stop-Flow Lithography in a Microfluidic
Device. Dendukuri, D., et al. Lab Chip20127 (7), 818–828 (ref (145)) Copyright 2012 Wiley.]
(e) Inertial flow lithography particles. Before fabrication, the device
used to shape flow and the necessary photomask is predesigned using
uFlow. Pillars in the device create complex flow geometries, and a
shaped photomask produces particles of the desired shape. Scale bar
is 100 μm. [Reproduced from Two-Photon Continuous Flow Lithography, Advanced Materials201524 (10), 1304–1308 (ref (146)) Copyright 2015 Wiley.] (f) Coaxial flow lithography particles.
A 3D-printed device shapes the coaxial flow. Scale bar is 100 μm.
[Reproduced from Destgeer, G., et al. Lab Chip2020, 20 (19), 3503–3514 (ref (22)) with permission from
The Royal Society of Chemistry.] Engineering systems and close-up
views of particle fabrication region adapted from Lewis, C. L., et
al. Anal. Chem.2010, 82 (13), 5851–5858 (ref (142)) with permission from The Royal Society of Chemistry.