Optische Partikelmanipulation in mikrofluidischen Kanälen mit Hilfe integrierter VCSEL-basierter optischer Fallen
FacultiesFakultät für Ingenieurwissenschaften und Informatik
In recent years, the field of microfluidics has gained increasing interest. Thousands of researchers have developed new microfluidic components for flow transport, for liquid analysis, mixture, or separation. Microfluidic platforms allow for the miniaturized, integrated, parallelized, and automated handling of biological and chemical samples. Optical manipulation by use of optical traps offers the advantage of avoided contamination. The combination with microfluidics offers an attractive tool for analysis and manipulation. Conventional laser sources for optical traps, however, tend to be expensive and require bulky setups. With the ultimate goal of miniaturization, laser sources with smaller dimensions are to be found. Vertical-cavity surface-emitting lasers (VCSELs) have been proven to be excellent light sources for the optical manipulation of microparticles inside microfluidic channels. Their small dimensions and their low power consumption enable a direct integration with microfluidic channels. Furthermore, due to their vertical emission, two-dimensional optical trap patterns can be realized. Besides their use in typical macroscopic optical trapping setups, VCSELs allow for a direct integration with the microfluidic components, enabling the realization of portable modules for optical particle manipulation. Such integrated modules with dimensions of a few centimeters can hardly be imagined with other laser sources. This thesis shows the fabrication of the required components for the realization of miniaturized trap modules. The fabricated components include top- and bottom-emitting VCSEL arrays with reduced device pitches as well as the corresponding chip carriers and polymeric microchannel chips. After characterization of the lasers, manipulation experiments with micrometer-sized polystyrene particles are demonstrated, both in a macroscopic trapping setup and in the manufactured integrated trap modules.
Subject HeadingsMikrofluidik [GND]