The research objective of this collaborative project is to develop and verify a physics-based model to reveal and quantitatively understand the fundamental physical processes of femtosecond laser-matter interactions in high aspect ratio microstructures. The study employs a combination of experimental and mathematical modeling approaches. Femtosecond laser-matter interactions in high aspect ratio microstructures will be experimentally observed using the pump-probe imaging, optical emission spectroscopy, and other techniques. Important process parameters, such as laser ablation rate, laser- induced plasma (due to the target vaporization and/or hydrodynamic expansion) and shock wave propagation speed, plasma temperature and electron number density, will be measured. The numerical model is based on the solution of Maxwell?s wave equation and hydrodynamic equations, and will be improved and verified by comparing simulations with measurements.
If successfully completed, the benefits of this project will be to set up a solid science base for femtosecond laser-matter interactions in high aspect ratio microstructures. This will establish femtosecond laser micromachining as a direct, flexible, and single-step technology that can realize a precise and controlled production of high-aspect ratio microstructures, which will have a big impact on microelectromechanical system, automotive, aerospace, and optics industries, where the demand for high aspect ratio microstructures has been increasing. The research results will be published in related journals and presented at technical conferences. Direct interactions with companies will be performed for research result dissemination. This interdisciplinary project provides a good opportunity for the training of graduate students. Undergraduate students and students from underrepresented groups will also be involved in the project. Animation demonstration kits based on the project results will be sent to the high schools in the neighborhood of Illinois Institute of Technology, which have high minority enrollment. This will promote the interest of high school students in science and engineering.
