Researchers from the University of Twente in the Netherlands have shown how to use topological tweezers to control active fluids. Topological tweezers are structured light patterns that can be used to manipulate the motion of particles in a fluid. Active fluids are fluids that are driven out of equilibrium by some internal mechanism, such as chemical reactions or thermal fluctuations.

In their experiments, the researchers used topological tweezers to create vortices in an active fluid. Vortices are swirling patterns of fluid that can transport particles and objects around. The researchers showed that they could use the topological tweezers to control the size, shape, and rotation of the vortices. This could have potential applications in microfluidics, where precise control of fluid flow is important.

The researchers also showed that they could use topological tweezers to create topological defects in an active fluid. Topological defects are points or lines in a fluid where the fluid's properties change abruptly. In active fluids, topological defects can act as sources or sinks of particles and objects. The researchers showed that they could use the topological tweezers to control the creation and destruction of topological defects. This could have potential applications in the study of soft matter physics, where topological defects play a role in many different phenomena.

The research is published in the journal Nature Physics.