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.