Three-dimensional optofluidic control using reconfigurable thermal barriers

Microfluidics allows for the precise control of small sample volumes through spatial confinement and exact routing of fluids. Usually, this is achieved by physical barriers. However, the rigidity of these barriers limits flexibility in certain applications. We introduce an optofluidic approach that leverages structured light and photothermal conversion to create dynamic, reconfigurable fluidic boundaries that can be easily integrated in existing setups. This system enables the controlled manipulation of fluids and particles by generating adjustable three-dimensional thermal landscapes. We demonstrate that our reconfigurable approach replicates the functions of traditional barriers and allows real-time adjustments for tasks such as individual particle steering and size-based sorting in heterogeneous mixtures. These results highlight the potential for adaptive and multifunctional microfluidic systems in applications such as chemical synthesis, lab-on-chip devices and microbiology.