The present invention relates to a SDFAST (Self Dilution for Faster Antimicrobial Susceptibility Testing), which is a microfluidic device that can perform self-dilution and does not require any pumps or valves to accomplish multiplexed microfluidic processes. SDFAST is designed using AutoCAD and fabricated using micro-milling machine. It consists of two polymethyl methacrylate (PMMA) rectangular plates which are in contact throughout the operation. The first plate is the bottom one that serves as lines of wells. The second plate is the top one that acts as a lid and seals the system. The second plate has complementary designs that echo the wells in the first plate, which allows fluidic channels to be formed.