VCSEL-Based Optical Trapping Systems for Microfluidic Applications

Optical trapping and manipulation by laser beams offers the unique possibility to handle
single micrometer-sized particles such as living cells without any mechanical contact,
damage or contamination. A second hot topic in biology is microfluidics, where the examination
of biological samples in channel structures with widths below 100 µm reduces
the used sample volume significantly. While the combination of both techniques results in
attractive lab-on-a-chip structures for particle sorting and analysis, the commonly bulky
trapping setup is contradictory to the miniaturized concept. Here, the use of vertical-cavity
surface-emitting lasers (VCSELs) as light sources in optical trapping systems allows a strong
reduction of the setup complexity owing to the small dimensions, low cost and high beam
quality of these devices.