Kim, Junbeom An, Heseong Seo, Yoojin Jung, Youngmee Lee, Jong Suk Choi, Nakwon Bong, Ki Wan 2024-01-20T02:02:31Z 2024-01-20T02:02:31Z 2021-09-01 2017-03 1932-1058 https://pubs.kist.re.kr/handle/201004/123003 Flow Lithography (FL) is the technique used for the synthesis of hydrogel microparticles with various complex shapes and distinct chemical compositions by combining microfluidics with photolithography. Although polydimethylsiloxane (PDMS) has been used most widely as almost the sole material for FL, PDMS microfluidic chips have limitations: (1) undesired shrinkage due to the thermal expansion of masters used for replica molding and (2) interfacial delamination between two thermally cured PDMS layers. Here, we propose the utilization of ultraviolet (UV)-curable PDMS (X-34-4184) for FL as an excellent alternative material of the conventional PDMS. Our proposed utilization of the UV-curable PDMS offers three key advantages, observed in our study: (1) UV-curable PDMS exhibited almost the same oxygen permeability as the conventional PDMS. (2) The almost complete absence of shrinkage facilitated the fabrication of more precise reverse duplication of microstructures. (3) UV-cured PDMS microfluidic chips were capable of much stronger interfacial bonding so that the burst pressure increased to similar to 0.9 MPa. Owing to these benefits, we demonstrated a substantial improvement of productivity in synthesizing polyethylene glycol diacrylate microparticles via stop flow lithography, by applying a flow time (40 ms) an order of magnitude shorter. Our results suggest that UV-cured PDMS chips can be used as a general platform for various types of flow lithography and also be employed readily in other applications where very precise replication of structures on micro-or submicrometer scales and/or strong interfacial bonding are desirable. Published by AIP Publishing. English AMER INST PHYSICS HYDROGEL MICROPARTICLES MULTIPLEXED DETECTION GAS SEPARATIONS PDMS PARTICLES CHANNELS POLY(DIMETHYLSILOXANE) MICROSTRUCTURES DIFFUSION MEMBRANES Flow lithography in ultraviolet-curable polydimethylsiloxane microfluidic chips Article 10.1063/1.4982698 1 BIOMICROFLUIDICS, v.11, no.2 BIOMICROFLUIDICS 11 2 scie scopus 000404339800010 2-s2.0-85018278385 Biochemical Research Methods Biophysics Nanoscience & Nanotechnology Physics, Fluids & Plasmas Biochemistry & Molecular Biology Biophysics Science & Technology - Other Topics Physics Article HYDROGEL MICROPARTICLES MULTIPLEXED DETECTION GAS SEPARATIONS PDMS PARTICLES CHANNELS POLY(DIMETHYLSILOXANE) MICROSTRUCTURES DIFFUSION MEMBRANES