Investigations on laser direct writing and laser micro-3D printing of metals and ceramics towards MEMS structures printing for functional applications [RESTRICTED THESIS-03 Months]

Abstract

The growing demand for high-performance Microelectromechanical Systems (MEMS) in fields such as biomedical devices, energy harvesting, and flexible electronics necessitates advanced micromanufacturing techniques capable of processing multifunctional materials with sub-micron precision. This thesis investigates two laser-based fabrication methodologies-Laser Direct Writing (LDW) and Laser Micro-3D Printing-to develop metallic and ceramic microstructures tailored for MEMS applications. LDW, employing a 10.6 μm CO₂ laser, is utilized for direct synthesis of porous laser-induced graphene (LIG) on polyimide substrates. Optimized parameters (4.5 W laser power, 15 mm/s scan speed) produced uniform graphene structures exhibiting high conductivity and porous morphology, confirmed by Raman spectroscopy with characteristic D (~1350 cm⁻¹), G (~1580 cm⁻¹), and 2D (~2700 cm⁻¹) peaks. The fabricated LIG-based strain sensors demonstrated excellent mechanical resilience, surviving over 1250 bending cycles without degradation.