Un uomo impossibile.

La struttura degli origami 31.10.17

Lo studio delle pieghe degli origami immaginati come atomi in un reticolo sta aiutando i ricercatori a scoprire i comportamenti complessi e strani nascosti in strutture semplici.

In 1970, an astrophysicist named Koryo Miura conceived what would become one of the most well-known and well-studied folds in origami: the Miura-ori. The pattern of creases forms a tessellation of parallelograms, and the whole structure collapses and unfolds in a single motion — providing an elegant way to fold a map. It also proved an efficient way to pack a solar panel for a spacecraft, an idea Miura proposed in 1985 and then launched into reality on Japan's Space Flyer Unit satellite in 1995.

Back on Earth, the Miura-ori has continued to find more uses. The fold imbues a floppy sheet with form and stiffness, making it a promising metamaterial — a material whose properties depend not on its composition but on its structure. The Miura-ori is also unique in having what's called a negative Poisson's ratio. When you push on its sides, the top and bottom will contract. But that's not the case for most objects. Try squeezing a banana, for example, and a mess will squirt out from its ends.

Researchers have explored how to use Miura-ori to build tubes, curves and other structures, which they say could have applications in robotics, aerospace and architecture. Even fashion designers have been inspired to incorporate Miura-ori into dresses and scarves.

Now Michael Assis, a physicist at the University of Newcastle in Australia, is taking a seemingly unusual approach to understanding Miura-ori and related folds: by viewing them through the lens of statistical mechanics.

Assis' new analysis, which is under review at Physical Review E, is the first to use statistical mechanics to describe a true origami pattern. The work is also the first to model origami using a pencil-and-paper approach that produces exact solutions — calculations that don’t rely on approximations or numerical computation.

Condividi il post di Tiziano Caviglia Blog su Facebook Condividi il post di Tiziano Caviglia Blog su Twitter Condividi il post di Tiziano Caviglia Blog su WhatsApp Condividi il post di Tiziano Caviglia Blog su Telegram Condividi il post di Tiziano Caviglia Blog via Email