Femtosecond laser fabrication and characterization of microchannels and waveguides in methacrylate-based polymers

Abstract

Femtosecond laser ablation is a promising method for producing polymeric microfluidic devices: it is a high precision processing technology resulting from an efficient energy deposition, while simultaneously minimizing heat conduction and thermal damage to the surrounding material. This work reports on the characterization of microchannels and waveguides fabricated by femtosecond laser technology in methacrylate-based polymers, precisely in thermoplastic poly(methyl methacrylate) (PMMA) and in a new material based on a high efficiency UV-curing process of methacrylic monomers bearing hydrophilic polyethylene glycol chains, namely tetraethylene glycol dimethacrylate and poly(ethylene glycol) methacrylate (PEG-MA). Microchannels in PMMA and PEG-MA, fabricated by parallel multi-scans, have sharp edges and low roughness, as investigated by Environmental Scanning Electron Microscopy and laser profilometer. Surface and physico-chemical properties after fs-laser processing were further studied by contact angle measurements and Attenuated Total Reflectance FTIR spectroscopy. Moreover, preliminary tests showed the refractive index of fs-laser PEG-MA exposed zones is different with respect to that of the surrounding polymer, suggesting that PEG-MA can be a good candidate to manufacture microfluidic devices containing integrated optic elements.

Picosecond laser ablation for silicon micro fuel cell fabrication

“…Rather than repeat the scan 7 for each channel individually, all channels were ablated consecutively with each scan -distributing the generated heat more homogeneously and minimizing the HAZ.…”

“…In recent years, laser ablation has gained some popularity [5][6][7] in microfluidics fabrication. The advantages of laser ablation include rapid prototyping, maskless multilevel material removal and noncontact operation.…”

Fabrication of biocompatible monolithic microchannels with high pressure‐resistance using direct polymerization of PEG‐modified PMMA

“…In this article, we present the use of a new material, that is, a PEG‐modified PMMA (PEGMA for brevity), for the fabrication of monolithic microchannels that can withstand pressures up to 12 MPa and that are inherently biocompatible . This has been achieved by successive direct UV‐photo partial polymerization of PEGMA layers through a printed photomask, followed by a bonding step in which all layers are assembled by completion of the polymerization process, resulting in a rapid and low‐cost method to produce microfluidic structures.…”