AiroFoam®: A Non-Newtonian Fluid

When we decided to start designing protective cases for larger devices, we realised we needed a protective material which would be light enough to use in larger quantities for larger devices. AiroShock® worked brilliantly for our protective phone cases and it was time to try something new. Enter AiroFoam®. This clever material is very lightweight because of its molecular structure+ as a non-Newtonian fluid. 

Wondering what a non-Newtonian fluid is? Read on and we’ll explain more, including what uses non-Newtonian fluids have, and which Mous products contain AiroFoam®.

What is a non-Newtonian fluid?

A non-Newtonian fluid is a liquid which doesn’t follow Newton’s law of viscosity*. Newton’s law claims that a fluid will have a constant viscosity – how thick or runny it is – under stress. Non-Newtonian fluids will do something different. Under stress, a non-Newtonian fluid can become more or less viscous. The molecules in the non-Newtonian fluid might move closer together or further apart and so behave more like a liquid or a solid. The change might happen when you shake a non-Newtonian fluid, rub it, or, in the case of AiroFoam®, drop it!

What are some everyday non-Newtonian fluids?

You might not realise it, but a lot of very common household items are non-Newtonian fluids. When you rub your shampoo it becomes a foam, custard forms a skin as it cools and cornstarch gets thicker the more forcefully you stir it. These are all examples of non-Newtonian fluids changing their viscosity under stress. Some non-Newtonian fluids react to how long they are under stress and others react to the amount of stress. A non-Newtonian fluid might become more or less viscous under stress. For example, ketchup gets runnier when you shake it out of the bottle, but AiroFoam® will form a hard shell on impact.

AiroFoam® as a non-Newtonian fluid: how does it work?

AiroFoam® is made of a series of exceptionally intelligent molecules. They gather to form strong hydrogen bonds as soon as they experience an impact. This turns the material from a soft, malleable foam into a hard, protective shell which guards against shock. The particles rush together to protect your device. The hydrogen bonds between the molecules temporarily break on impact and absorb the energy which would otherwise hit your device. When the impact ends and the energy has dissipated, the material returns to its soft resting state. It’s this change under stress which makes AiroFoam® a non-Newtonian fluid. There is no limit to the number of times this change can occur, or to the number of times AiroFoam® can protect your device from impact damage. Clever. 

How do we use our non-Newtonian fluid?

Because it’s a non-Newtonian fluid, AiroFoam® can be impressively lightweight while still being extremely protective. This makes it perfect for protecting larger devices. We’ve incorporated this clever non-Newtonian fluid into our iPad cases and our MacBook sleeves, available to shop now.


+Molecular structure is the pattern the molecules in something are arranged in.

*Viscosity means how thick or runny something is. If it’s thicker, the molecules are closer together and if it’s runnier, they’re further apart.

This is Mous

A group of twenty-somethings founded Mous in 2014 when they realised other products on the market weren’t able to offer them the versatile range of experiences they wanted from their tech. They saw a way to do better because they believed in the transformative power of technology. So they designed an ambitious range of products which allowed their tech to do more. Mous now make a wide range of tech accessories including wireless chargers, phone mounts and phone cases. 

Live without limits.

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