Nathan Vani

Freely readable over here: dl.acm.org/doi/pdf/10.1...

Fun collab, with a fair share of geometry, fabrication and computer graphics! Multilayered pneumatic chambers open up numerous avenues: 3+ networks, non-developable, differential pressurization… still lots of mechanics to be understood and geometries to be programmed!

With computer geometry wizards Ofir & Mélina, we also introduce a purely geometric inverse design algorithm. Usable to program any developable geometry, without any costly optimisation!

Staggering the networks while tuning the widths of alternating tubes allows for a precise control of the curvature of the inflated object through differential contraction. It’s just like a bilayer, but continuously programmable!

Through successive soldering, we managed to fabricate two distinct, bound networks of tubes. Our new inflatables are far stiffer than usual thin-sheets inflatables due to their homogeneous thickness — no free rotation along the welding lines!

Our article on multilayer inflatables has been published! A physics-computer graphics collab in which we introduce a new type of thin-sheet balloons and discuss their shape programming 🎈 @espciparispsl.bsky.social @pmmh-lab.bsky.social
dl.acm.org/doi/pdf/10.1...

Je soutiendrai demain 24 juin ma thèse de doctorat à Jussieu, amphi 55A à 14h, ouverte à tous. Il y aura une retransmission via Zoom -- lien sur demande !

Poster pour la conférence Functionality through Nonlinearity comme illustration

Asymmetric bending boundary layer: The λ-test | PNAS We investigate the mechanics of two asymmetric ribbons bound at one end and pulled apart at the other ends. We characterize the elastic junction ne...

Last insight: when we design objects under tension such as inflatables we often disregard bending stiffness under the assumption of large tensile stress. But this junction angle is constant and very much macroscopic! Bending stiffness matters regardless of the loading!
www.pnas.org/doi/10.1073/...

Moreover, we discuss the rotationnal behavior of the junction, there is some cool mechanics with a “universal” behavior in that discussion.

(bending stiffness is usually, like, really hard to measure precisely for thin/complex membranes and sheets)

Since the shape scales as a function of the tensile force in the system, the junction angle between the two rods does not change regardless of the loading. We show how we can harness this cool property for a precise, purely visual measurement of bending stiffnesses!

In it, we show how this junction is a combination of two self-similar, classical solutions of Euler’s Elastica. The shape of this boundary layer is determined by the (a)symmetry of the bending stiffness

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/...