Fiber laser for high-rate ultrafast micromachining

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Ultrafast laser micromachining is a microfabrication technology relying on light pulses of such short duration that thermal damage of the surrounding material is negligible. Furthermore, because light can be focussed through appropriate lenses to spot sizes in the micrometer range, it is possible to use laser light to carve on surfaces and cut through the bulk of all kind of materials with very high spatial control. This technology has been developed over the past decades and is now progressively moving from research to industrial applications, be it for the processing and functionalization of surfaces, the fabrication of miniature biomedical implants, diagnosis platforms and microelectromechanical systems.***Typical research systems operate with pulse repetition rates in the kHz range, while industrial turnkey systems operate at MHz to allow for rapid processing of complex 3D components and large surface areas. Currently, no such system for rapid laser micromachining exists at McGill or in the Montreal area. The applicants that rely on such machining, presently outsource these tasks which leads to a loss of control, time and money. Having such a system at McGill will enable us to take full control over the fabrication of microscale devices for biomedical applications and functional surfaces and therewith accelerate our research programs, enable us to engage in new research fields, establish new collaborations with academic and industry partners and provide hands-on training to students of various research fields on laser machining.***Aside all the above mentioned advantages, ultrafast laser machining of materials inevitably comes with the ultrafast production of nanoparticles. Prof. Kietzig has established in the past that laser-machined surfaces are highly reactive. Accordingly nanoparticles that are commonly exhausted to the ambient air in most research and industrial facilities do not only contribute to nanoparticle pollution in the environment but are also potentially even more hazardous as they readily react with their surrounding environment. Alongside the various projects targeting surface processing and device fabrication, we propose to utilize the industrial MHz laser to produce nanoparticles under controlled conditions at industrial process rates and exploit (1) functionalizing them directly during the micromachining process to render them harmless and/or (2) collecting these for potential further use as catalysts in other processes or safe disposal. Therewith we ambition to develop new standards for micromachining that is waste-free and safer-by-design. Accordingly, the acquisition of such a laser will not only drive forward the research efforts of at least 5 research groups and provide exceptional training opportunities on state-of-the-art laser equipment to students, but also benefit the operators of laser micromachining systems, co-workers in the same company and eventually the greater public that inhales air-borne nanoparticles.**