#softmatter — Public Fediverse posts

What looks like a simple bubble can become a delivery system. New materials store therapeutic gases and release them through controlled interfacial dynamics.

🔗 https://www.science.org/doi/10.1126/science.aef9968

#Fluids #Interfaces #SoftMatter #DrugDelivery #Physics

Rolling Down Soft Surfaces

Place a rigid ball on a hard vertical surface, and it will free fall. Stick a liquid drop there, and it will slide down. But researchers discovered that with a soft sphere and a soft surface, it’s possible to roll down a vertical wall. The effect requires just the right level of squishiness for both the wall and sphere, but when conditions are right, the 1-millimeter radius sphere rolls (with a little slipping) down the wall.

Rolling requires torque, something that’s usually lacking on a vertical surface. But the team found that their soft spheres got the torque needed to roll from their asymmetric contact with the surface. More of the sphere contacted above its centerline than below it. The researchers compared the way the sphere contacted the surface to a crack opening (at the back of the sphere) and a crack closing (at the front of the sphere). That asymmetry creates just enough torque to roll the sphere slowly. The team hopes their discovery opens up new possibilities for soft robots to climb and descend vertical surfaces. (Image and research credit: S. Mitra et al.; via Gizmodo)

#adhesion #fluidDynamics #physics #science #slip #softMatter #solidMechanics

Ultra-Soft Solids Flow By Turning Inside Out

Can a solid flow? What would that even look like? Researchers explored these questions with an ultra-soft gel (think 100,000 times softer than a gummy bear) pumped through a ring-shaped annular pipe. Despite its elasticity — that tendency to return to an original shape that distinguishes solids from fluids — the gel does flow. But after a short distance, furrows form and grow along the gel’s leading edge.

Since the gel alongside the pipe’s walls can’t slide due to friction, the gel flows by essentially turning itself inside out. Inner portions of the gel flow forward and then split off toward one of the walls as they reach the leading edge. This eversion builds up lots of internal stress in the gel, and furrowing — much like crumpling a sheet of paper — relieves that stress. (Image and research credit: J. Hwang et al.; via APS News)

#flowVisualization #fluidDynamics #instability #physics #pipeFlow #science #softMatter #solidMechanics #stress

Cooking Perfect Cacio e Pepe

In cooking, sometimes the simplest recipes are the toughest to master. Cacio e pepe — a classic three-ingredient Italian pasta — is an excellent example. Made properly, the sauce of cheese and black pepper combines with starchy water to coat the pasta in a uniform, cheesy sauce. Or, if you’re me, you wind up with a pasta sauce flecked with stringy clumps of melted cheese. Fortunately for those of us who have yet to master this one, a new research paper has us covered with tips to make the perfect cacio e pepe.

The key to that elusive silky sauce, they found, is the starch – water – cheese combination. Your water needs just the right amount of starch — they found that between 1 – 4% starch by (cheese) mass worked. If the starch concentration is too low (which can easily happen in pasta water), you’ll get the clumpy cheese mess that so frequently happens in my kitchen. Temperature is also critical; if the water is too hot when it’s added, then it can destabilize the sauce. Check out the pre-print’s Section V for the scientific, supposedly foolproof, recipe. I know I’ll be trying it! (Image credit: O. Kadaksoo; research credit: G. Bartolucci et al. pre-print; via APS News)

#cooking #emulsion #fluidDynamics #phaseSeparation #physics #rheology #science #softMatter

Our #preprint where we derive an #activeGel #model with entropic elasticity of the #microstructure from the thermodynamic constraints on the dynamics of #myosin molecular motors is now updated!

Hopefully more readable, and with the example of a #cyst like contractile sphere.

#cytoskeleton #rheology #activeMatter #softMatter #actomyosin

Our #preprint where we derive an #activeGel #model with entropic elasticity of the #microstructure from the thermodynamic constraints on the dynamics of #myosin molecular motors is now updated!

Hopefully more readable, and with the example of a #cyst like contractile sphere.

#cytoskeleton #rheology #activeMatter #softMatter #actomyosin

Our #preprint where we derive an #activeGel #model with entropic elasticity of the #microstructure from the thermodynamic constraints on the dynamics of #myosin molecular motors is now updated!

Hopefully more readable, and with the example of a #cyst like contractile sphere.

#cytoskeleton #rheology #activeMatter #softMatter #actomyosin

Our #preprint where we derive an #activeGel #model with entropic elasticity of the #microstructure from the thermodynamic constraints on the dynamics of #myosin molecular motors is now updated!

Hopefully more readable, and with the example of a #cyst like contractile sphere.

#cytoskeleton #rheology #activeMatter #softMatter #actomyosin

Our #preprint where we derive an #activeGel #model with entropic elasticity of the #microstructure from the thermodynamic constraints on the dynamics of #myosin molecular motors is now updated!

Hopefully more readable, and with the example of a #cyst like contractile sphere.

#cytoskeleton #rheology #activeMatter #softMatter #actomyosin

@mechanobio

A new #preprint where we derive an #activeGel #model with entropic elasticity of the #microstructure and give interpretations of the thermodynamic constraints on the dynamics of #myosin molecular motors.

#cytoskeleton #rheology #activeMatter #softMatter