title: Capillarity Guided Patterning of Microliquids.
abstract: Soft lithography and other techniques have been developed to investigate biological and chemical phenomena as an alternative to photolithography-based patterning methods that have compatibility problems. Here, a simple approach for nonlithographic patterning of liquids and gels inside microchannels is described. Using a design that incorporates strategically placed microstructures inside the channel, microliquids or gels can be spontaneously trapped and patterned when the channel is drained. The ability to form microscale patterns inside microfluidic channels using simple fluid drain motion offers many advantages. This method is geometrically analyzed based on hydrodynamics and verified with simulation and experiments. Various materials (i.e., water, hydrogels, and other liquids) are successfully patterned with complex shapes that are isolated from each other. Multiple cell types are patterned within the gels. Capillarity guided patterning (CGP) is fast, simple, and robust. It is not limited by pattern shape, size, cell type, and material. In a simple three-step process, a 3D cancer model that mimics cell-cell and cell-extracellular matrix interactions is engineered. The simplicity and robustness of the CGP will be attractive for developing novel in vitro models of organ-on-a-chip and other biological experimental platforms amenable to long-term observation of dynamic events using advanced imaging and analytical techniques.
authors: Division of WCU (World Class University) Multiscale Mechanical Design, Seoul National University, Seoul, Korea.
authors: Myeongwoo
authors: M
authors: Kang
authors: Division of WCU (World Class University) Multiscale Mechanical Design, Seoul National University, Seoul, Korea.
authors: Woohyun
authors: W
authors: Park
authors: Division of WCU (World Class University) Multiscale Mechanical Design, Seoul National University, Seoul, Korea.
authors: Sangcheol
authors: S
authors: Na
authors: Interdisciplinary Program for Bioengineering, Seoul National University, Seoul, Korea.
authors: Sang-Min
authors: SM
authors: Paik
authors: Division of WCU (World Class University) Multiscale Mechanical Design, Seoul National University, Seoul, Korea.
authors: Hyunjae
authors: H
authors: Lee
authors: Division of WCU (World Class University) Multiscale Mechanical Design, Seoul National University, Seoul, Korea.
authors: Jae Woo
authors: JW
authors: Park
authors: Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Korea.
authors: Ho-Young
authors: HY
authors: Kim
authors: Division of WCU (World Class University) Multiscale Mechanical Design, Seoul National University, Seoul, Korea.|Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul, Korea.
authors: Noo Li
authors: NL
authors: Jeon
mesh_terms: D002196:Capillaries; D002469:Cell Separation / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005782:Gels / Q000737:chemistry*; D044085:Microfluidics / Q000295:instrumentation*; D054802:Molecular Imprinting / Q000295:instrumentation*; D066330:Printing, Three-Dimensional / Q000295:instrumentation*; D012996:Solutions / Q000737:chemistry*
chemical_list: D005782:Gels; D012996:Solutions
keywords: lab-on-a-chip devices; liquid patterning; microfluidics; surface tension