Active nematic fluids borrow their ingredients from biology. Using long, rigid microtubules and kinesin motor proteins capable of cross-linking between and “walking” along tubules, researchers create these complex flow patterns. Here, a team took the system a step further by seeding the flow with a hydrogel that turns into a polymer when exposed to light. Then, by shining light patterns on the flow, the scientists can create rigid or flexible structures inside the active fluid. In this case, they show off some of the neat flow patterns they can create. (Video and image credit: G. Pau et al.)

https://fyfluiddynamics.com/2024/06/growing-hydrogels-in-an-active-fluid/

#2024gosm #activeMatter #activeNematicFluid #fluidDynamics #hydrogel #physics #polymerEffects #science

Ferrofluids are a great platform for exploring liquids and magnetism. Here, researchers trap ferrofluid droplets along an oil-water meniscus and then apply a magnetic field that makes the drops repel one another. The results are crystalline patterns formed from magnetic droplets. For a given patch of drops, increasing the magnetic field’s strength pushes drops further apart. But changing the drops’ size and levels of self-attraction also shifts the patterns. Check out the video to see the crystals in action. (Video and image credit: H. Khattak et al.)

https://fyfluiddynamics.com/2024/06/making-magnetic-crystals-from-ferrofluids/

#2024gosm #ferrofluid #fluidDynamics #magneticField #magnetohydrodynamics #physics #science

To fly stably, parachutes need to deform and allow some air to pass through their canopy. In this video, researchers investigate kirigimi parachutes, inspired by a form of paper art that uses cuts to create three-dimensional shapes. After laser-cutting, these disks are dropped — or placed in a wind tunnel — to observe how they “fly” at different speeds. Sometimes they flutter or bend; other shapes elongate in the flow. (Video and image credit: D. Lamoureux et al.; via GoSM)

https://fyfluiddynamics.com/2024/05/kirigami-parachutes/

#2024gosm #drag #fluidDynamics #parachutes #physics #science #solidMechanics