A bizarre metafluid packs programmable properties

Amazing stuff!

"... In this case, the metafluid’s small components are air-filled elastomer spheres between 50 and 500 microns wide, which are suspended in silicon oil. These tiny balls will collapse under pressure, and pop back out when that pressure is relieved, and those two different states will change the metafluid’s properties.

So, for example, when in their full circular shape the balls scatter light, making the fluid look opaque. But under pressure, when they collapse into half-moon shapes, they act like tiny lenses, focusing light and making the metafluid transparent. ..."

"... “We are just scratching the surface of what is possible with this new class of fluid,” ... “With this one platform, you could do so many different things in so many different fields.” ...
Metamaterials — artificially engineered materials whose properties are determined by their structure rather than composition — have been widely used in a range of applications for years. ..."

From the abstract:

"The pursuit of materials with enhanced functionality has led to the emergence of metamaterials—artificially engineered materials whose properties are determined by their structure rather than composition. Traditionally, the building blocks of metamaterials are arranged in fixed positions within a lattice structure. However, recent research has revealed the potential of mixing disconnected building blocks in a fluidic medium. Inspired by these recent advances, here we show that by mixing highly deformable spherical capsules into an incompressible fluid, we can realize a ‘metafluid’ with programmable compressibility, optical behaviour and viscosity. First, we experimentally and numerically demonstrate that the buckling of the shells endows the fluid with a highly nonlinear behaviour. Subsequently, we harness this behaviour to develop smart robotic systems, highly tunable logic gates and optical elements with switchable characteristics. Finally, we demonstrate that the collapse of the shells upon buckling leads to a large increase in the suspension viscosity in the laminar regime. As such, the proposed metafluid provides a promising platform for enhancing the functionality of existing fluidic devices by expanding the capabilities of the fluid itself."

Harvard's bizarre "metafluid" packs programmable properties Harvard engineers have created a strange new “metafluid” – a liquid that can be programmed to change properties, like its compressibility, transparency, viscosity and even whether it’s Newtonian or not.

Intelligent liquid Researchers develop metafluid with programmable response (original news release)

Shell buckling for programmable metafluids (no public access)

When pressure is removed from the fluid, the capsules pop back into their spherical shape.