Vatsal Sanjay

YouTube video by University of Twente / Universiteit Twente Waarom wordt er altijd zo gedrongen bij de uitgang van een festival? #HoeZitUT?

Watch the never-boring Pepijn Hoekstra explaining our work on #clogging from our labs! @utwente.bsky.social
www.youtube.com/shorts/ZYHiE...

🎉 Congratulations to Dr. Jochem Meijer for winning the KIVI Hoogendoorn Fluid Mechanics Award 2024! His thesis "Particles, drops, and bubbles in gradient fields" was recognized as the best PhD thesis of 2023-24. Supervised by @detleflohse.bsky.social 👏 #FluidMechanics #PhD​​​​​​​​​​​​​​​​

@jnandeep.bsky.social (@poftwente.bsky.social) discussing his master thesis project on singularities with surfactants at the Max Planck meeting. How do surfactants influence coalescence of sessile drops? Teaser talk as Jnan explores the different dynamics across the Peclet-Marangoni parameter space

Introducing CyberDiver!

This new untethered robotic device is capable of actively controlling impact forces and splash dynamics during water entry.
arxiv.org/abs/2503.20702

Design source files:
github.com/harrislab-br...

Work led by #harrislab PhD student John.

This very cool paper, and Carl's very nice short thread describing the value of basic research in biology, may be of interest to @thecopperdoctor.bsky.social @oneofmanychris.bsky.social and others.

Some pictures from yesterday’s Wim-van-Saarloos-70-fest at the Dutch academy @knaw-nl.bsky.social. Happy birthday, Wim!

NB it’s the same room as where Pauli received his Lorentz medal.

"Living Histories". Detlef Lohse | #TheLivingHistoriesSeries The Living Histories series: https://tinyurl.com/TheLHSeries Very brief "trajectory talks" on personal histories leading to the becoming of biological physicists / quantitative biologists / neuroscientists / mathematicians/ complexity scientists. Series concept: Srividya Iyer-Biswas Series organizers: Srividya Iyer-Biswas, Tapa Bhattacharjee, Jasmine Nirody, and Charlie Wright Series website: https://tinyurl.com/TheLHSeries

So inspiring to hear my mentor, Detlef Lohse (@poftwente.bsky.social), share his scientific journey in this @thelhseries.bsky.social! His thoughts on curiosity, mentorship, and the "puzzle solving" joy of science resonate deeply. A must-watch! Always so much to learn. bit.ly/3DXBixh

Pierre-Simon Laplace - Wikipedia

Happy birthday to Pierre-Simon Laplace, the *actual* father of so called "Bayesian" Inference.

en.wikipedia.org/wiki/Pierre-...

fun.. :D

The Gallery of Soft Matter 2025 @apsdsoft.bsky.social has some amazing entries this year. Check them out here: engage.aps.org/dsoft/galler....
Make sure to vote! Not sure about the deadline, but there’s a QR code at the DSOFT table with all the details.

📣 Heads up! During 2025 #BiophysicsWeek the Membrane Structure and Function Subgroup is hosting a Webinar about “Milestones and Future Directions” in our field! It’s intended to be pedagogically accessible, and if you don’t mind me also presenting, then please consider signing up and logging in! 🧪🧬

FRIDAY - MARCH 14, 2025

Albert Einstein’s Birthday (1879)
Also born on Pi-Day: Steph Curry, Simone Biles, and Billy Crystal

Theo Jansen's Strandbeests are massive, wind-powered kinetic sculptures designed to roam Dutch beaches. Conceived as a way to kick up sand that would replenish nearby dunes, the beests have grown into a decades-long obsession for the artist.
fyfluiddynamics.com/?p=23401

Excited to share our new paper in @pnas.org doi.org/10.1073/pnas...! Ice cubes often appear cloudy because, as water freezes, air bubbles get trapped and scatter light. But how does freezing rate affect the shape of the bubbles?

The @ec-euclid.bsky.social mission to map part of the Universe has made a fascinating new discovery 💫

Our scientists are part of the team analysing the latest images from space 🔭
Read more 👉 tinyurl.com/bdze5xcy

#DUresearch #DUinspire @esa.int #Einstein

Confinement, Jamming, and Adhesion in Cancer Cells Dissociating from a Collectively Invading Strand, W. Wang, R. A. Law, E. P. Ipiña, K. Konstantopoulos, and B. A. Camley, PRX Life 3 (2025) 🎉
go.aps.org/41xXR4N
#Biophysics #Cancer #Jamming #CollectiveBehavior #Mechanobiology #SoftMatter #Metastasis

It was fun to uncover this story—bridging microbial physiology, biological pattern formation, & active matter physics. The results may even have implications for controlling microbes in applications. We'd love your feedback. Please report/share with whoever might be interested! [8/8]

Many biological fluids are polymer solutions, whose viscoelasticity can enhance cell swimming and promote large-scale mixing.
We showed that the core-shell organization also arises in polymer solutions, but with fascinating additional flow fluctuations. [7/8]

We then developed a biophysical model describing this interplay quantitatively. The model recapitulates the experiments, and also yields criteria for predicting the different ways in which confined bacterial populations self-organize under different conditions. [6/8]

Cells consume O2, creating a gradient that alters motility: (i) They move up the gradient toward the droplet boundary via aerotaxis, & (ii) They stop swimming in the anoxic droplet core and accumulate. These motility variations in turn reshape O2 fluxes. A feedback loop! [5/8]

By simultaneously measuring cell distributions, oxygen concentration, and swimming-generated fluid flow, we figured out that this spatial organization is driven by the interplay between cell metabolism-generated oxygen gradients and collective motility. [4/8]

Surprisingly, when the droplets are big and concentrated, the cells self-organize into a concentrated inner "core" of immotile cells surrounded by a more dilute outer "shell" of highly motile cells. (See movie in 1st tweet.) In some cases, the core shrinks and disappears. [3/8]

Bacteria often inhabit confined spaces, such as biological tissues/gels & soils/sediments, where metabolites are scarce. What influence does confinement have on a population of motile bacteria?
We addressed this question by studying quasi 2D droplets of swimming E. coli. [2/8]

Excited to release our latest work:
doi.org/10.1101/2025...

Here, we describe how confined bacterial suspensions self-organize into structured domains of different motilities, in response to oxygen limitations🦠🍥

Bluetorial follows! [1/8]

Science under threat | Royal Society The Royal Society will use its voice and the expertise of our Fellows to resist the various challenges to science.

Science advances our economic, physical, and social and cultural wellbeing, and is key to a sustainable future. However, we live in times of great change, and the values that have driven science for the benefit of humanity are under threat. Read our statement here: royalsociety.org/news/2025/02...

To get an executive summary, have a look at our blog post: blogs.comphy-lab.org/Blog/2025-JF... and/or an `AI` generated general summary at bit.ly/4ifVrxg

This is our first paper with a JFM Notebook—an excellent initiative by J. Fluid Mech. to host interactive code and data. It greatly enhances reproducibility and transparency in fluid dynamics research—a commendable step forward.
cocalc.com/Cambridge/S0...

GitHub - VatsalSy/The-role-of-viscosity-on-drop-impact-forces Contribute to VatsalSy/The-role-of-viscosity-on-drop-impact-forces development by creating an account on GitHub.

In the spirit of transparent science, the full source code for our simulations is freely available: github.com/VatsalSy/The... This ensures reproducibility and allows further exploration of drop-impact phenomena.

At moderate impact velocities and low viscosity, a singular flow focusing causes the second peak to exceed the first. This narrow ‘island’ vanishes if viscosity grows or if the impact is too energetic, quenching the focused jet.

Near rebound, a Worthington jet forms within the retracting drop and induces a second force peak. Its amplitude depends on viscosity, impact speed, and surface tension, linking inertial flow focusing to capillarity and viscous dissipation.