Life on Earth is comprised mostly of microbes with significant implications in disease and carbon cycling. However, their dimensions and mobility make microbes challenging to analyse on-chip. A sub-micron resolution microfluidic system (sub-microfluidics) capable of trapping and releasing single Escherichia coli bacteria is presented. The fabrication method based on electron-beam and cast molding lithography is described, as well as the trap and release of single E. coli. The release time from the trap is found to depend on cell morphology.