Torrspinning

Torrspinning is a technique used in soft matter research and microfluidics to manipulate fluids and suspensions by spinning a sample inside a torus-shaped chamber. The term combines torus, the doughnut-shaped geometry, with spinning, reflecting the method’s core geometry and motion. In practice, a sealed toroidal vessel is mounted on a motor that imposes a controlled angular velocity, while the pressure inside the chamber is regulated and monitored in torr. The geometry and motion produce persistent toroidal flow fields that interact with the sample’s microstructure.

The typical setup consists of a toroidal reaction vessel, a variable-speed drive, a pressure control system, and temperature regulation. Samples can include polymer solutions, colloidal suspensions, liquid crystals, or emulsions. Rotation speeds commonly range from several hundred to several thousand revolutions per minute, and chamber pressure can be set from low vacuum to near-atmospheric, depending on the material.

The mechanism relies on centrifugal and Coriolis effects within the toroidal cavity. The resulting shear and circulation can align anisotropic particles, promote structured mixing, or control phase separation and crystallization. The technique offers tunable flow patterns by adjusting speed, pressure, temperature, and geometry.

Applications include orienting liquid-crystal domains, guiding self-assembly in nanocomposites, and enabling steady-state mixing in microreactors. Advantages include localized, controllable shear and scalable processing; limitations involve complex flow characterization and material sensitivity to high shear.

Safety and materials compatibility are important, as rapid rotation and pressure changes can pose hazards. See also: toroidal flow, spin coating, microfluidics.