Optofluidics

Optofluidics is a multidisciplinary field that combines optics and microfluidics to manipulate light and fluids on a single chip. It aims to enable integrated optical interrogation and fluid handling for chemical and biological analysis, imaging, sensing, and actuation. Devices typically integrate optical components such as waveguides, lenses, and detectors with microfluidic channels and valves made from materials like PDMS, glass, or polymers.

Key operating principles include optical manipulation using light-based forces to trap or move particles and cells, photothermal heating to drive fluid flow, and evanescent-field or plasmonic sensing for detecting refractive index changes or molecular binding within a channel. Optical interrogation methods such as fluorescence detection, Raman spectroscopy, and on-chip imaging are commonly used alongside microfluidic transport.

Architectures include on-chip waveguides interfaced with microchannels, optofluidic lenses or micromirrors, and microcavities or photonic-crystal structures that enhance light–matter interactions. Platforms may employ droplet microfluidics where droplets serve as isolated reactors, with optical readout or actuation for generation, sorting, or merging.

Applications span lab-on-a-chip diagnostics, environmental sensing, high-throughput screening, single-cell analysis, and portable sensing. Advantages of optofluidics include compact, low sample volumes, non-contact manipulation, fast readout, and potential for monolithic integration with electronics. Challenges include thermal management, photodamage in biological samples, fabrication complexity, reliability, and scaling for mass production.

Research directions include integrating nanoscale photonic components, plasmonics, and nonlinear optics with microfluidics, as well as leveraging advanced materials and computational design to improve sensitivity and throughput. The field continues to evolve toward fully integrated, chip-scale analytical platforms for rapid, point-of-care testing.