Stable generation of multiple chemical gradients using in-situ formed nanoporous membranes

We developed a gradient generator of multiple chemicals using self-assembled particles in microchannels. The porous membranes based on the assembled particles allow the stable gradient generation without any convection flow disturbance and leakage. Moreover, they are more robust in dry environment and have long-term storage potential compared to hydrogel based membranes. Dynamic spatial control and the parallel preferential chemotaxis assay of salmonella typhimurium were successfully demonstrated. Our proposed devices are expected to be utilized for mimicking the real microenvironment for cells and various drug screening