Despite the many advantages of microchemical systems and their successful applications in chemical engineering research, one major drawback greatly limiting their use is their susceptibility to channel clogging for flows containing particulate matter. Hence, the aim of the proposed research is to overcome the challenge of clogging in microfluidic devices and to design microfluidic systems that can tolerate particulate matter and synthesize solid materials according to their specifications (e.g. size, purity, morphology). To reach this goal, we apply a combined experimental and theoretical approach, in which the experimental results will lead to model development reflecting the particle formation and interaction kinetics and their coupling to the hydrodynamics. The novel concept of the proposal is to devise engineering strategies to handle the particulate matter inside the reactor depending on if the solid material is i) an unwanted and insoluble by-product of a reaction, or ii) the target compound (e.g. nanoparticle synthesis or crystallization of organic molecules). Depending on the case we will design different ultrasound application strategies and introduce nucleation sites to control the location of particle formation within the microchannel. This project will provide fundamental insight into the physico-chemical phenomena that result in particle formation, growth and agglomeration processes in continuous flow microdevices, and will provide a theoretical tool for the prediction of the dynamics of particle-particle, particle-wall and particle-fluid interactions, leading to innovative microreactor designs.