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.