A Single-Mask Process for 3-D Microstructure Fabrication in PDMS

Hosseini, Yahya; Zellner, Phillip; Agah, Masoud

doi:10.1109/jmems.2012.2231402

Cited by 12 publications

(10 citation statements)

References 25 publications

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“…The Pyrex wafer is melted at high temperatures under a furnace causing the molten glass to conform to the shape of the 3D silicon features (Figure 2(e)). 27 The glass substrate master mold is left behind after the silicon substrate is etched away using KOH (Figure 2(f)). Low cost PDMS devices were mass produced using the glass master mold.…”

Section: B Device Fabricationmentioning

confidence: 99%

Three dimensional passivated-electrode insulator-based dielectrophoresis

et al. 2015

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In this study, a 3D passivated-electrode, insulator-based dielectrophoresis microchip (3D pDEP) is presented. This technology combines the benefits of electrodebased DEP, insulator-based DEP, and three dimensional insulating features with the goal of improving trapping efficiency of biological species at low applied signals and fostering wide frequency range operation of the microfluidic device. The 3D pDEP chips were fabricated by making 3D structures in silicon using reactive ion etching. The reusable electrodes are deposited on second glass substrate and then aligned to the microfluidic channel to capacitively couple the electric signal through a 100 lm glass slide. The 3D insulating structures generate high electric field gradients, which ultimately increases the DEP force. To demonstrate the capabilities of 3D pDEP, Staphylococcus aureus was trapped from water samples under varied electrical environments. Trapping efficiencies of 100% were obtained at flow rates as high as 350 ll/h and 70% at flow rates as high as 750 ll/h. Additionally, for live bacteria samples, 100% trapping was demonstrated over a wide frequency range from 50 to 400 kHz with an amplitude applied signal of 200 Vpp. 20% trapping of bacteria was observed at applied voltages as low as 50 Vpp. We demonstrate selective trapping of live and dead bacteria at frequencies ranging from 30 to 60 kHz at 400 Vpp with over 90% of the live bacteria trapped while most of the dead bacteria escape. V C 2015 AIP Publishing LLC.

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Section: B Device Fabricationmentioning

confidence: 99%

Three dimensional passivated-electrode insulator-based dielectrophoresis

et al. 2015

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“…It is important to note, therefore, that an especially interesting single mask process technique was developed to create 3-D structures in PDMS microfluidic devices. 47 The process used a mask with varying opacity that could be used in an ion etching process. This resulted in the fabrication of glass relief molds that allowed channels of continuously varying depths to be produced, as well as weirs and pillars.…”

Section: Fundamentalsmentioning

confidence: 99%

Micro Total Analysis Systems: Fundamental Advances and Biological Applications

et al. 2013

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“…The fabrication process flow from silicon to PDMS and hydrogel starts with etching the desired structures in silicon as explained previously (Fig. 1) . In brief, a photomask parameter related to the geometrical value and etch time is generated based on the desired width and depth of structures as shown in Eqs.…”

Section: Methodsmentioning

confidence: 99%

“…For instance, in blood vessels, cells are interacting inside circular channels, with varying diameter along with multiple branches and joints, with each other and their surrounding ECM environment. In this report, we have extended our previous work in 3‐D tissue micropatterning, working toward much more complex and physiologically relevant surface topographies in 3‐D tissue utilizing a single mask, single etch process using reactive ion etching (RIE) lag.…”

Section: Introductionmentioning

confidence: 95%

Bio‐inspired microstructures in collagen type I hydrogel

Hosseini

Verbridge

Agah

2014

J Biomedical Materials Res

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This article presents a novel technique to fabricate complex type I collagen hydrogel structures, with varying depth and width defined by a single fabrication step. This technique takes advantage of reactive ion etching lag to fabricate three-dimensional (3-D) structures in silicon. Then, a polydimethylsiloxane replica was fabricated utilizing soft lithography and used as a stamp on collagen hydrogel to transfer these patterns. Endothelial cells were seeded on the hydrogel devices to measure their interaction with these more physiologically relevant cell culture surfaces. Confocal imaging was utilized to image the hydrogel devices to demonstrate the robustness of the fabrication technique, and to study the cell-extracellular matrix interaction after cell seeding. In this study, we observed that endothelial cells remodeled the sharp scallops of collagen hydrogel structures and compressed the structures with low degree of slope. Such patterning techniques will enhance the physiological relevance of existing 3-D cell culture platforms by providing a technical bridge between the high resolution yet planar techniques of standard lithography with more complex yet low resolution 3-D printing methods.

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A Single-Mask Process for 3-D Microstructure Fabrication in PDMS

Cited by 12 publications

References 25 publications

Three dimensional passivated-electrode insulator-based dielectrophoresis

Three dimensional passivated-electrode insulator-based dielectrophoresis

Micro Total Analysis Systems: Fundamental Advances and Biological Applications

Bio‐inspired microstructures in collagen type I hydrogel

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