Ferrofluid travelling around soap bubbles towards a magnet
Ferrofluid is a fluid made of colloidal nano-sized magnetic particles suspended in a hydrophobic solution. Some home-made ferrofluid can be made from an oil base (like vegetable oil) mixed with tiny particles of ferrite (pure iron) which can be found in printer toners/developers.
The ferrofluid moves around the bubbles first due to capillary action- but is then drawn through by a magnet.
The original source really needs to be viewed as it’s fantastic!
Ferrofluids create all kinds of fascinating shapes when exposed to magnetic fields. In this video, Dianna from Physics Girl shows off what happens when you combine a ferrofluid with glowsticks and explains how ferrofluids get some of their unique properties. Ferrofluids consist of tiny nanoparticles of magnetic material that are surrounded by surfactants and suspended in a carrier fluid. This creates a fluid whose shape depends on gravity, surface tension, and the local magnetic field. By manipulating the relative strength of these forces, you can create everything from spikes to maze-like patterns to whatever this is. (Video credit and submission: Physics Girl)