The major public health problem of sepsis requires breakthrough technologies for ultra-fast diagnosis. Dense, fluidized granular beds are ideal systems for liquid-solid or gas-solid exchange processes. They are widely used in industry thanks to their high surface-to-volume ratio. Over the past decade, microfluidics and lab-on-a-chip have enabled numerous advances, particularly in biological sample preparation. We propose to develop a versatile microfluidic platform that will enable the creation of such dense, fluidized beds. We will first work on the incorporation of membranes into microchannels, drawing on the patented know-how developed in the laboratory. We will then study and characterize the granular beds, and finally test them for the detection of bacteria in biological samples. This work will be carried out in collaboration with our physicists (LEDNA) and biologist (LERI) partners at CEA Saclay.