Soft matter physics: bio-inspired fluid mechanics, fluid-solid couplings in soft & living matters

Joined October 2020
Photos and videos
Jeongeun Ryu retweeted
The molecular origin of this rapid softening remains unknown. Future studies and new genetic tools are needed to uncover the signals driving the ultra-fast mechanical remodeling of the cell wall. Paper here: science.org/doi/10.1126/scie…
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Jeongeun Ryu retweeted
Together, these measurements rule out rapid water transport or sudden turgor changes as drivers of closure. Instead, closure is triggered by rapid softening of the epidermal wall: bending comes from release of pre-stress in the turgid mesophyll after weakening of the outer layer
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Jeongeun Ryu retweeted
In a plant cell, reduced stiffness come from either pressure loss or softer cell wall, each leaves opposite shape signatures. Profilometry shows increased bulging, exactly what is expected from cell wall softening, not pressure loss. FEM quantify it: 40% drop in wall stiffness!
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Jeongeun Ryu retweeted
To probe the trap’s active mechanism, we measured cell stiffness using indentation. One side changes, the other doesn't! The outer epidermis softens while the inner epidermis remains unchanged. Real-time measurements show that this softening occurs within seconds of triggering.
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Jeongeun Ryu retweeted
A natural idea is hydraulics: plants move by redistributing water, so why not the Venus flytrap? Because it's too slow! Tissue-swelling and cell pressure-probe experiments show that water transport cannot keep up with the trap’s rapid active closure.
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Jeongeun Ryu retweeted
We isolate the plant’s active motor from its mechanical amplifier by cutting the trap or measuring the force generated by a clamped trap. Even without the snap, the active deformation remains surprisingly fast, unfolding in just a few seconds.
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Jeongeun Ryu retweeted
Fresh off the press in @ScienceMagazine! @fluidity_x and Yoël’s work on the actuation of the Venus flytrap. 🪴⚡ No muscles. No nerves. So what powers the trap? Cutting the trap suppresses its mechanical amplifier, the snap-through instability, and reveals the active motion.
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Jeongeun Ryu retweeted
Jun 11
Ever since Charles Darwin proclaimed the carnivorous Venus flytrap one of the “most wonderful” plants in the world, scientists have been trying to work out how it snaps shut so quickly on its prey. A research team has now snapped a key piece of the puzzle in place. go.nature.com/4oktoRc
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Jeongeun Ryu retweeted
The Venus flytrap is renowned for its ultrafast snap traps, which can capture insects in a fraction of a second. New research reveals that trap closure is triggered by a rapid softening of the epidermal cell walls, uncovering the physical mechanism behind this remarkable movement. Learn more this week in Science: scim.ag/4fG2Bg3
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Jeongeun Ryu retweeted
Faced with a long-haul flight, Tadashi Tokieda decided to do what he likes best. He started folding a sheet of paper. Watch the full @OxUniMaths Public Lecture, including lots of paper, an elephant & the mathematical magic of origami. youtube.com/watch?v=8p02Dtmy…
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Jeongeun Ryu retweeted
New pre-print out. Colloids can assemble into Turing patterns through diffusiophoresis. I hadn't fully appreciated the focusing effect of diffusiophoresis in biological systems until I saw the Ornate Boxfish on display at @Birch_Aquarium
25 May 2023
📢Thrilled to share -re-print alert from @LIFE_Boulder. Led by @ben_alessio22 "Diffusiophoresis-enhanced Turing Patterns". Comparison of fish patterns with and without diffusiophoresis (pc credits to Birch Aquarium for the Ornate Boxfish and craigjhowe for the Jewel Moray Eel).
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Jeongeun Ryu retweeted
Inextensible balloons are a versatile solution for soft robotics! @biosoftact @CNRS
From a 🍷 to an 🥚 and even a 🌱 this fabric-based soft robotic gripper can handle an extraordinarily wide range of irregular shapes. @biosoftact @CNRS Read the article: ow.ly/uxxc50O4Npe
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Jeongeun Ryu retweeted
PRFluids Editors' Suggestion: Downslope granular flow through a forest of obstacles Baptiste Darbois Texier, Yann Bertho, and Philippe Gondret go.aps.org/40wagmK #GranularFlow Experiments at various inter-pillar distances observe how forest density slows granular flow.
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Jeongeun Ryu retweeted
Bravo Olivier!
#ERCAdG 🇪🇺 🏆 | Félicitations à Olivier Pouliquen, directeur de recherche @CNRS à l'IUSTI qui est lauréat de la bourse européenne @ERC_Research Advanced Grant 2022 en Provence ! ➡️ Découvrez son portrait : provence-corse.cnrs.fr/fr/pe…
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Jeongeun Ryu retweeted
When I was in Death Valley many years ago, I wondered on the origin of polygonally patterned crusts of salt which one can see there. Today I bumped into the beautiful @PhysRevX of Jana Lasser et al: The answer is diffusive convection in porous media, journals.aps.org/prx/abstrac…
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Jeongeun Ryu retweeted
Meet the “capillarytron”—a @CNRS developed rheometer that can access fluid properties other rheometers can’t. physics.aps.org/articles/v16…
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Jeongeun Ryu retweeted
The capillarytron — a new rheometer for dense colloidal suspensions developed by Bruno, Yoël and Bloen @INSIS_CNRS journals.aps.org/prx/abstrac…
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Jeongeun Ryu retweeted
⚡MATLAB 2D Fluid Simulation⚡ Incompressible 2D MATLAB FDM Navier-Stokes. Fluid simulation calculated with Jacobi method and Runge-Kutta 4 integration for advection.
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Jeongeun Ryu retweeted
Very excited to share the latest work from our lab, led by great postdoc @AntoineVian. We developed a new technique to measure osmotic pressure directly in vivo and in situ, within living tissues. Check out the 🧵 below or the preprint in the link here ➡️biorxiv.org/content/10.1101/…
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