3D-glass molds for facile production of complex droplet microfluidic chips

Abstract

In order to leverage the immense potential of droplet microfluidics, it is necessary to simplify the process of chip design and fabrication. While polydimethylsiloxane (PDMS) replica molding has greatly revolutionized the chip-production process, its dependence on 2D-limited photolithography has restricted the design possibilities, as well as further dissemination of microfluidics to non-specialized labs. To break free from these restrictions while keeping fabrication straighforward, we introduce an approach to produce complex multi-height (3D) droplet microfluidic glass molds and subsequent chip production by PDMS replica molding. The glass molds are fabricated with sub-micrometric resolution using femtosecond laser machining technology, which allows directly realizing designs with multiple levels or even continuously changing heights. The presented technique significantly expands the experimental capabilities of the droplet microfluidic chip. It allows direct fabrication of multilevel structures such as droplet traps for prolonged observation and optical fiber integration for fluorescence detection. Furthermore, the fabrication of novel structures based on sloped channels (ramps) enables improved droplet reinjection and picoinjection or even a multi-parallelized drop generator based on gradients of confinement. The fabrication of these and other 3D-features is currently only available at such resolution by the presented strategy. Together with the simplicity of PDMS replica molding, this provides an accessible solution for both specialized and non-specialized labs to customize microfluidic experimentation and expand their possibilities.

Development of moisture-proof polydimethylsiloxane/aluminum oxide film and stability improvement of perovskite solar cells using the film

“…Second, we investigated why the WVTR is enhanced when the PDMS/AlO x double layer is used. PDMS is employed because of its low cost, 21 chemical stability, 22 easy process to fabricate lm or mold, 23 high transparency, 24 and common usage in the microuidic cell [25][26][27] and other devices. 28,29 In addition, it exhibits the hydrophobic property.…”

Coding of Experimental Conditions in Microfluidic Droplet Assays Using Colored Beads and Machine Learning Supported Image Analysis

“…Chip Design and Production : 3D designs of microfluidic chips were created using AutoCAD 2015 (Autodesk Corp., USA), see Figure S1 (Supporting Information). They were used to produce negative molds with the FEMTOPRINT technology which were further replicated as polydimethylsiloxane (PDMS) chips …”

A model for designing intraocular pressure-regulating glaucoma implants

“…Using this technique, different channel heights can be easily fabricated within one microfluidic chip. This would be extremely cumbersome using other classical manufacturing techniques, such as photolithography, due to the need of multiple photolithography steps with precise alignment, which is very difficult to achieve even when using a mask aligner [47].…”