Rapid prototyping method for 3D PDMS microfluidic devices using a red femtosecond laser

Abstract

A rapid prototyping technique is demonstrated which uses a red femtosecond laser to produce a metallic mould which is then directly used for the replica moulding of PDMS. The manufacturing process can be completed in less than 6 h making it a viable technique for testing new designs quickly. The technique is validated by creating a microfluidic device with channels of height and depth of 300 µm, with a ramp test structure where the height and width of the channels reduces to 100 µm to demonstrate the techniques 3D capabilities. The resulting PDMS device was easily removed from the metallic mould and closely replicated the shape aside the expected shrinkage during thermal curing. As the technique uses a single replica process, the surface roughness at the base of the channels corresponds to the un-ablated polished metal mould, resulting in a very low surface roughness of 0.361 nm. The ablated metallic mould surface corresponds to the top of the PDMS device, which is bonded to glass and does not affect the flow within the channels, reducing the need for optimisation of laser parameters. Finally, the device is validated by demonstrating laminar flow with the no-slip condition.

Molecular Separation by Using Active and Passive Microfluidic chip Designs: A Comprehensive Review

“…Recently, the light incorporation (femtosecond laser) protocols have been more attractive than others relying on light energy so‐called “micro‐ stereolithography” or “laser microfabrication”. [ 216,271,272 ]…”

“…Recently, the light incorporation (femtosecond laser) protocols have been more attractive than others relying on light energy so-called "micro-stereolithography" or "laser microfabrication". [216,271,272] Laser modular techniques such as laser-induced plasmaassisted ablation [273] and monolithic digital patterning with sub-sequent laser pyrolysis [274] could be introduced to the μFFE device. Nevertheless, the turn of quality in the performance in engraved microchannels will be made after optimization, a complementary step in the fabrication process.…”

Low-cost microfluidics: Towards affordable environmental monitoring and assessment

“…Typically, a CO 2 laser with a wavelength of 10.6 µm are used (Mohammed et al, 2016;Persson et al, 2022). Indeed, sophisticated laser machine or reduced wavelength (e.g., femtosecond lasers) can be applied to further improve the cutting resolution, yet these methods are not suitable for low-cost microfluidics since extra costs are inevitably required (Elgohary et al, 2020;Saadat et al, 2020;Andriukaitis et al, 2022). When it comes to the materials used in laser micromachining, both hard materials such as glass and soft materials such as PMMA, cyclic olefin copolymer (COC) and even paper could be used (Islam et al, 2018;Lin et al, 2019b).…”

Cultivation of Bovine MSCs on Plant-Based Scaffolds in a macrofluidic Single-Use Bioreactor for Cultured Meat

“…In this study, we evaluated the use of laser welding to incorporate nylon bilayers, the main component of the macrofluidic single-use bioreactor (MSUB) construction. Our primary goal is to demonstrate compatibility with cell culture and utility as a rapid prototyping method for large-scale fluidics, similar to microfoudics only at a large scale [43][44][45][46][47][48]. Significantly, we demonstrate that cells can proliferate and potentially differentiate on scaffolds within macrofluidic systems.…”