Post-processing of glass substrates for microfluidic and MEMS applications

The advancement of microfabrication technologies has paved the way for the development of highly integrated, miniaturized systems used in diverse applications, ranging from bioanalysis and environmental sensing to communication and energy harvesting. Among the various material platforms available, glass substrates have emerged as a versatile and indispensable component in the fabrication of microfluidic and Micro-Electro-Mechanical Systems (MEMS) [ 1–10 ]. Owing to their excellent chemical resistance, optical transparency, electrical insulation, and thermal stability, glass materials serve as ideal substrates in applications that require optical detection, fluidic manipulation, or electrical isolation. In both MEMS and microfluidic device fabrication, subtractive processes such as wet or dry etching define the functional geometries on glass [ 11 ]. However, to ensure the desired performance and reliability of these devices, the substrates must undergo a range of post-processing steps after etching. These include surface treatment, cleaning, thin film deposition, photolithographic patterning, and bonding. Each of these steps plays a critical role in preparing the substrate for integration, encapsulation, and long-term operation.