iiinova — where your digital self keeps evolving

Reposted by Etienne Jambon-Puillet

Udo Sen @uddaloksen.bsky.social · 14/07/2026

1926: Van der Pol writes down the "relaxation oscillator" — slow build-up, sudden discharge, on repeat. 1297: Washburn describes "salt creeping" — crystals crawling out of an evaporating salt solution. Turns out they're the same story. 🧵 👇

111

Reposted by Etienne Jambon-Puillet

Joel Marthelot @joelmarthelot.bsky.social · 13/06/2026

Fresh off the press! Jeongeun and Yoël’s work on the lightning-fast 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. www.science.org/doi/10.1126/...

22311

Etienne Jambon-Puillet @ejambonp.bsky.social · 09/03/2026

Very cool! It always amazes me how different problems can look very similar once put into equations. The sublimation of sharp tips also yields a curvature decreasing as t^(-1/2) because the receding velocity scales with the curvature locally (doi.org/10.1038/s414...).

132

Reposted by Etienne Jambon-Puillet

Elizabeth Beston @elizabethbeston.bsky.social · 13/01/2026

It’s been too long since I posted some Zoothamnium - a colonial ciliate that contracts when disturbed. So pretty! #marineplankton 🦑

2569

Reposted by Etienne Jambon-Puillet

Etienne Jambon-Puillet @ejambonp.bsky.social · 09/10/2025

Did you know you can manipulate hundreds of microparticles using phototactic algae? This is what we show in our last preprint, led by T. Laroussi and J. Bouvard: arxiv.org/abs/2509.08133 🧵👇

1193

Etienne Jambon-Puillet @ejambonp.bsky.social · 09/10/2025

In the manuscript, we model these bioconvection rolls with simulations of phototactic advection-diffusion and demonstrate how to harness them for particle transport.

000

Etienne Jambon-Puillet @ejambonp.bsky.social · 09/10/2025

Depending on the particles’ density, they are either attracted to or repelled by the dense algae region, allowing various modes of micromanipulation.

100

Etienne Jambon-Puillet @ejambonp.bsky.social · 09/10/2025

But since these algae are slightly denser than water, concentrating them generates bioconvection rolls. These flows act on a much larger scale than individual algae and can thus efficiently transport large particles over millimetric distances!

100

Etienne Jambon-Puillet @ejambonp.bsky.social · 09/10/2025

Chlamydomonas reinhardtii is a phototactic alga. When exposed to a strong light stimulus, it swims away from it. This allows us to locally concentrate them with a light stimulus.

100

Etienne Jambon-Puillet @ejambonp.bsky.social · 09/10/2025

Did you know you can manipulate hundreds of microparticles using phototactic algae? This is what we show in our last preprint, led by T. Laroussi and J. Bouvard: arxiv.org/abs/2509.08133 🧵👇

1193

Reposted by Etienne Jambon-Puillet

Nathan Vani @nathanvani.bsky.social · 17/03/2025

Our article on the junction of slender objects under tension has been published @pmmh-lab.bsky.social! We discuss a cool phenomenon found in numerous systems, from kirigamis, kuttsukigami from @abcroll.bsky.social, and inflatables to more traditional tearing/peeling www.pnas.org/doi/10.1073/...

2164

Reposted by Etienne Jambon-Puillet

Antoine Deblais @antoinedeblais.bsky.social · 13/02/2025

The 🪱 mania continues! In our latest study, led by Rosa, we explored the locomotion and dynamics of living worms—acting as active polymers—navigating a porous environment made of 3D-printed pillar arrays. And we found something surprising...

1163

Etienne Jambon-Puillet @ejambonp.bsky.social · 07/01/2025

Inspired by natural system, the non-linear properties of such `hairy channels' can be harnessed to build passive flow control systems such as relief valves, flow rectifiers, or more complex non-linear networks.

030

Etienne Jambon-Puillet @ejambonp.bsky.social · 07/01/2025

Coupling the two gives a reduced order fluid-structure interaction model that quantitatively reproduces the experiments. It also suggests that the system can be described by a single dimensionless parameter combining elastic, viscous and geometrical properties.

120

Etienne Jambon-Puillet @ejambonp.bsky.social · 07/01/2025

To rationalize it, I model the hair array as a deformable porous media whose size is dictated by the bending of individual hairs under fluid loading.

120

Etienne Jambon-Puillet @ejambonp.bsky.social · 07/01/2025

This yields a non-linear hydraulic resistance that I explore experimentally and theoretically for laminar flows.

110

Etienne Jambon-Puillet @ejambonp.bsky.social · 07/01/2025

When confined in a channel of size comparable to the hairs themselves and subject to a pressure driven flow, they strongly perturb the flow and if soft enough they bend and change the channel geometry significantly.

120

Etienne Jambon-Puillet @ejambonp.bsky.social · 07/01/2025

Many natural surfaces such as our skin, our tongue, or our blood vessels are covered with dense arrays of soft hair-like structures.

110

Etienne Jambon-Puillet @ejambonp.bsky.social · 07/01/2025

New preprint: arxiv.org/abs/2501.01875 "Dense array of elastic hairs obstructing a fluidic channel" I guess it was time I post something here! Explanations below 🧵👇

1246