MEMS technology and Lab-on-a-Chip devices: exploring innovation in gas analysis and microtechnologies for heterogeneous catalysis studies

Micro-Electro-Mechanical Systems (MEMS) have revolutionized several scientific and industrial fields due to their unique ability to integrate mechanical and electrical functions at the microscale. In particular, MEMS technology has emerged as a critical driver of innovation in both micro gas chromatography (μGC) and heterogeneous catalysis, two fields that demand high precision, efficiency, and adaptability. In gas chromatography, the ongoing trend toward faster, more portable, and more efficient devices has seen MEMS-based systems become an essential tool in chemical analysis. The miniaturization of core components has enabled the creation of high-performance μGC systems that deliver rapid and accurate analyses, while significantly reducing the energy and space required for operation. Concurrently, MEMS-based microreactors have opened new possibilities in studying catalytic processes. These reactors, with their precise control over reaction conditions, scalable design, and intrinsic safety, offer unprecedented opportunities for exploring catalytic reactions and optimizing catalytic efficiency. This thesis investigates the design, development, and application of MEMS-based devices in the fields of gas analysis and heterogeneous catalysis. It presents novel approaches to the fabrication and integration of microcolumns and microreactors, emphasizing enhanced microcolumn integration while maintaining chromatographic resolution and catalytic performance. The research explores the adaptation of traditional fused silica columns to MEMS-based silicon and silicon-glass capillary columns, presenting experimental results and performance characterization. Novel wafer-level techniques such as pre-bonding deactivation and connection-free stationary phase deposition are introduced, improving scalability and integration into the commercially available micro gas chromatograph “PicoGC” from Pollution S.r.l. Additionally, a MEMS-based microreactor system is developed for studies in heterogeneous catalysis, with a case study on Thermochemical Water Splitting using CeO₂ nanorods. The study highlights operational advantages, including precise temperature modulation, and proposes hardware improvements and future research directions.