A Pdms-Sealed Hydrogel Device For Rapid And Accuarate Generation Of Various Concentration Gradients

We report a microfluidic device that can rapidly and accurately generate various concentration gradients for the chemotaxis study of bacterial cells by integrating hydrogel into polydimethylsilosane (PDMS) microchannels. We theoretically and experimentally demonstrated that the PDMS-sealed hydrogel (PSH) device produces various profiles of concentration gradients without flow-induced shear stresses. Furthermore the device exhibits remarkable advantages over conventional hydrogel-based (CHB) devices. For example, the PSH device prevents dehydration of hydrogel; guides diffusion of chemicals; generates concentration gradients rapidly; exhibits long-term durability; and is easy to handle. Using the PSH device, we demonstrate chemotaxis responses of bacterial cells in various concentration profiles