Fabrication of Colloidal Materials through Microfluidic Techniques.

Abstract

Microfluidics is the science and technology of fluid manipulation on the microscale through the creation of fluidic systems with a channel width of less than 500 μm. Since its appearance during the second half of the XXth century, this relatively young field has gained attention due to the properties arising because of the channel size reduction, such as the disappearance ofturbulent flows. Among the wide range of microfluidics applications, the creation of monodisperse colloidal systems is one of the most promising branches of this science. With the use of drop-generator microfluidic devices, stable monodisperse emulsions can be created, where each drop can behave as an independent micro-scale reactor, providing new possibilities in the research fieldsof chemical and biological analysis as well as new materials development. The main material used to build the devices is glass. Glass is stable and highly manipulablefrom a chemical and physical point of view. However, its manipulation to create the devicessometimes can lead to complex and risky operations. Therefore, the exploration of new easy-tomake and inexpensive procedures is necessary to approach microfluidics in an out-of-the-lab environment. In this report, the creation of drop-generator microfluidic devices based on dispensableneedles will be assessed, comparing their building procedure and performance to the ones observed in the case of glass-based devices. Furthermore, with the use of needle-baseddevices, functional colloidal systems based on polymer spheres are created as a practical application of the developed technique.