title: Designer hydrophilic regions regulate droplet shape for controlled surface patterning and 3D microgel synthesis.
abstract: A simple technique is presented for controlling the shapes of micro- and nanodrops by patterning surfaces with special hydrophilic regions surrounded by hydrophobic boundaries. Finite element method simulations link the shape of the hydrophilic regions to that of the droplets. Shaped droplets are used to controllably pattern planar surfaces and microwell arrays with microparticles and cells at the micro- and macroscales. Droplets containing suspended sedimenting particles, initially at uniform concentration, deposit more particles under deeper regions than under shallow regions. The resulting surface concentration is thus proportional to the local fluid depth and agrees well with the measured and simulated droplet profiles. A second application is also highlighted in which shaped droplets of prepolymer solution are crosslinked to synthesize microgels with tailored 3D geometry.
authors.affiliation: Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 65 Landsdowne Street, Cambridge, MA 02139, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Hancock
authors.forename: Fumiki
authors.initials: F
authors.lastname: Yanagawa
authors.forename: Yun-Ho
authors.initials: YH
authors.lastname: Jang
authors.forename: Jiankang
authors.initials: J
authors.lastname: He
authors.forename: Nezamoddin N
authors.initials: NN
authors.lastname: Kachouie
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kaji
authors.forename: Ali
authors.initials: A
authors.lastname: Khademhosseini
mesh_terms: D000818:Animals; D005782:Gels / Q000138:chemical synthesis*; D057927:Hydrophobic and Hydrophilic Interactions; D051379:Mice; D008855:Microscopy, Electron, Scanning; D041681:NIH 3T3 Cells; D036103:Nanotechnology / Q000379:methods*; D013499:Surface Properties
chemical_list: D005782:Gels