Through-holes, cavities and perforations in polydimethylsiloxane (PDMS) chips

Santisteban, Tomas Silva; Zengerle, Roland; Meier, Matthias

doi:10.1039/c4ra09586c

Cited by 12 publications

(8 citation statements)

References 26 publications

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“…The ratio of 6.5:1:2.5 used in the previous study resulted in a tendency of the substrate to break easily after curing. 17 This disadvantage shows the weak point of the micropattern formation, which occurs subsequent to stretching. Therefore, we chose a ratio of 20:1:1.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Iridescent and Glossy Effect on Polymer Surface Using Micro-/Nanohierarchical Structure: Artificial Queen of the Night Tulip Petals

Woo

et al. 2019

ACS Appl. Mater. Interfaces

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Many petals in nature have a hierarchical structure that imparts various optical properties. Among these, the petals of the Queen of the Night tulip exhibit an iridescent and glossy color due to the diffraction and scattering of light. Herein, we report a bioinspired micro-/nanohierarchical structure that mimics Queen of the Night tulip petal surfaces. Using a method that combined soft lithography and UV−ozone treatment, we fabricated nanoscale line patterns with a linewidth of 600 nm on microwrinkles of 15 μm width and 3 μm height. Using optical microscopy in the dark-field mode and monochromatic light diffraction measurements, we found that these hierarchical structures on a poly(dimethylsiloxane) (PDMS) substrate synergistically improved the scattering and diffraction effects, unlike the pristine, nano-, and microstructures. In addition, using a dye-colored PDMS material, we fabricated artificial Queen of the Night petals with iridescent and glossy effects. They show great potential for a range of applications, such as coloring, smart displays, dynamic gratings, and light-control devices.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Iridescent and Glossy Effect on Polymer Surface Using Micro-/Nanohierarchical Structure: Artificial Queen of the Night Tulip Petals

Woo

et al. 2019

ACS Appl. Mater. Interfaces

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“…The microchamber had a length of 32 mm, a width of 27 mm, and a height of 1 mm. A thin PDMS membrane was fabricated by the spin coating method. , Briefly, the PDMS prepolymer was poured onto a poly(tetrafluoroethylene) (PTFE) plate and rotated at a speed of 1200 rpm for 35 s using a spin coater (KW-4A, Xinyou, China). After curing it on a hot plate at 120 °C for 20 min, a PDMS membrane with a thickness of ∼50 μm was formed.…”

Section: Methodsmentioning

confidence: 99%

Stacked Catalytic Membrane Microreactor for Nitrobenzene Hydrogenation

Liu

Zhu

Liao

et al. 2020

Ind. Eng. Chem. Res.

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In the present study, a novel stacked catalytic membrane microreactor assembled by microfluidic sheets and gaspermeable membranes was developed for gas−liquid−solid multiphase catalytic reactions. The developed microreactor consisted of multilayered perforated microchannels for supplying liquid reactants and perforated microchambers for supplying gas reactants, which were separated by poly(dimethylsiloxane) membranes with coated catalysts. Gas and liquid reactants flowed through their independent passageways layer by layer. Gas reactants bidirectionally permeated through the gas-permeable membrane to the catalyst layer, improving the gas utilization. Catalyst layers were prepared and immobilized on the membranes through layer-by-layer self-assembly and in situ reduction technology. Unlike other stacked microreactors, the integration of microchannels, microchambers, and membranes into one unit circumvented flow maldistribution, low durability, and low throughput of the microreactor. Furthermore, the scale-up of the membrane microreactor could be easily realized by increasing the number of microfluidic sheets and membranes. The catalytic performance was evaluated by nitrobenzene hydrogenation over palladium nanocatalyst. Results showed that the stacked catalytic membrane microreactor enabled a stable and efficient operation for 50 h. As the number of stacked layers was increased, the durability was continuously increased. The conversion was increased with increasing hydrogen flow rate or decreasing nitrobenzene flow rate. In addition, the increased inlet nitrobenzene concentration led to more serious catalyst deactivation, which decreased the conversion. In general, the stacked catalytic membrane microreactor developed in this study creates a new approach to design membrane microreactors for multiphase catalytic reactions.

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“…The mold for the control circuit was manufactured with SU-8 3025 Photoresist, and all channels had a rectangular profile and a height of 20 μm. Molds were coated with C 4 F 8 following published protocols (51). Sylgard 184 (Dow Corning) was used to replicate PDMS chips from the molds with a process described before (52).…”

Section: Methodsmentioning

confidence: 99%

In situ characterization of the mTORC1 during adipogenesis of human adult stem cells on chip

Schneider

Platen

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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Mammalian target of rapamycin (mTOR) is a central kinase integrating nutrient, energy, and metabolite signals. The kinase forms two distinct complexes: mTORC1 and mTORC2. mTORC1 plays an essential but undefined regulatory function for regeneration of adipose tissue. Analysis of mTOR in general is hampered by the complexity of regulatory mechanisms, including protein interactions and/or phosphorylation, in an ever-changing cellular microenvironment. Here, we developed a microfluidic large-scale integration chip platform for culturing and differentiating human adiposederived stem cells (hASCs) in 128 separated microchambers under standardized nutrient conditions over 3 wk. The progression of the stem cell differentiation was measured by determining the lipid accumulation rates in hASC cultures. For in situ protein analytics, we developed a multiplex in situ proximity ligation assay (mPLA) that can detect mTOR in its two complexes selectively in single cells and implemented it on the same chip. With this combined technology, it was possible to reveal that the mTORC1 is regulated in its abundance, phosphorylation state, and localization in coordination with lysosomes during adipogenesis. High-content image analysis and parameterization of the in situ PLA signals in over 1 million cells cultured on four individual chips showed that mTORC1 and lysosomes are temporally and spatially coordinated but not in its composition during adipogenesis.microfluidics | stem cell differentiation | adipogenesis | mTORC1 regulation | multiplexed PLA

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Through-holes, cavities and perforations in polydimethylsiloxane (PDMS) chips

Abstract: We present a method to fabricate through-holes between 10 to 180 μm between polydimethylsiloxane (PDMS) layers of microfluidic large-scale integration platforms.

Cited by 12 publications

References 26 publications

Iridescent and Glossy Effect on Polymer Surface Using Micro-/Nanohierarchical Structure: Artificial Queen of the Night Tulip Petals

Iridescent and Glossy Effect on Polymer Surface Using Micro-/Nanohierarchical Structure: Artificial Queen of the Night Tulip Petals

Stacked Catalytic Membrane Microreactor for Nitrobenzene Hydrogenation

In situ characterization of the mTORC1 during adipogenesis of human adult stem cells on chip

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