MEMS microreactors


MEMS systems for applications in fluidics at micro level represent one of the most important applications of microsystem technologies in chemical engineering. The main stages of a chemical process are heat exchange, i.e. activation energy that defines reaction kinetics and mixing that ensures contact of reacting substance at the molecular level. Both of these stages proceed in microreactors in a controlled way, with good homogeneity throughout the volume, since dimensions are at a micrometer and submicrometer level. A consequence is a large surface to volume ratio and small diffusion path, both of which increase the mass transfer rate. These aspects ensure the possibility to achieve aggressive stages of chemical reactions that are unattainable in macroreactors due to phisycal, qualitative and safety reasons. Also, a microreactor can be integrated into microanalytical devices in the part befure the analysis in order to prepare the sample or to amplify signal.

     Microreactors include a very wide class of devices which are further classified according to their complexity, integration level, physical and chemical principles and the fields of application (microbiosystems, chemical synthesis, power sources like microfabricated fuel cells like SOFC – solid oxide fuel cells, etc.)

     Our Centre possesses know-how for design and technologies for fabrication of microreactors for certain applications. Microfabrication includes processes of bulk and surface micromachining of silicon, glass and some polymers (e.g. PDMS), techniques of deposition of metal and dielectric thin films with different purposes (heaters, catalysts), annodic bonding and bonding with buffer layer, photolithography, microplasma welding.

     Since research topics of the Centre include various MEMS sensors (pressure, temperature, chemical), there is a possibility to integrate these sensors with microreactors.

     One of the classes of microreactors of interest are photocatalytic microreactors with process acceleration through surface plasmons polaritons, owing to high localizations of optical feald near the surface of these structures.