This Review summarizes methods for constructing systems and structures at micron or submicron scales that have applications in microbiology. These tools make it possible to manipulate individual cells and their immediate extracellular environments and have the capability to transform the study of microbial physiology and behaviour. Because of their simplicity, low cost and use in microfabrication, we focus on the application of soft lithographic techniques to the study of microorganisms, and describe several key areas in microbiology in which the development of new microfabricated materials and tools can have a crucial role.

A low- or room-temperature bonding method was developed for fabrication of glass-based microfluidic chips without the requirement of clean environment and programmed high-temperature furnaces. After fundamental pretreatments, the glass substrates and cover plates to be bonded were sequentially soaked in concentrated sulfuric acid, washed with high-flow-rate tap water, de-ionized water and treated using HF steam as a necessary step. Finally, the plates were bonded by bringing the cleaned surfaces into close contact either under a continuous flow of de-ionized water or directly when treated with HF steam, and annealing at low-temperature (90%). The bonding quality of the chips was evaluated by employing SEM, shear strength testing procedure and electric current measurement at different applied voltages. The mechanism for the strong bonding strength was presumably related to the formation of a hydrolyzed layer on the glass plate surfaces after soaking them in acid or water for extended periods. Microfluidic chips bonded by the above method were evaluated in the CE separation of monofuctional reactive dye Cy5-labeled bioamines.