Janus is a newly developed material that helps regulate your personal microclimate by switching which way you put it on.

An Unpredictable Climate

The Aussie climate is pretty darn fickle. 

In pockets all over the country, on any given day, you could be waking up in sub-zero temps, and within an hour or two, be sweating it up as the mercury climbs into the high 20s, especially if you’re outside getting amongst it. 

So how do you prepare for a full day in nature with such a drastically mood-swingy climate to contend with? 

Some Chinese researchers may have found a solution.

The T-Shirt That Keeps You Warm And Cool

Meet Janus – a newly developed fabric that when facing outwards, reflects the heat of the sun, and while facing inwards, traps in heat radiation. Sounds kinda intense hey?

But when used in a T-shirt design, this fabric has the potential to keep you up to 8.1°C warmer, or 6°C cooler than typical black or white cotton T-shirts, depending on which way you wear it. Now we’re talking. 

So theoretically, you could wear the same single T-shirt all day and change the microclimate around you by a difference of 14°C, just by turning the shirt inside out (or outside in). 

How The Heck Does That Happen?

Like onions and ogres, this fabric has many layers, namely made up of polymer and cotton fibres with a bunch of fancy structures and coatings that help enhance or diminish heat.

On the side that keeps you warm, the fabric is coated in zinc and copper nanoparticles which are used to absorb the sun, and in turn, solar energy. But in this instance, the energy is used for heat, not electricity, keeping you all warm inside. 

Put your thang down, flip it, and reverse it to the cool side, and there’s a reaaal thin layer of aluminium which, like disco balls, reflects light away from its surface, and in that light, any heat that might’ve been sticking around. No word yet if this side of the T-shirt will blind passersby or make them want to dance. 

Importantly, this layer of aluminium is also porous, so any steam can evaporate right outta there. 

Because of the difference in temps on the two sides of the material, Janus can also produce energy – not enough to power a whole city, but way more than any T-shirt you currently own can. 

A Winner For The Environment

As Janus helps regulate our own personal microclimates, there’d be less of a need to control the climate around us through the use of air conditioning and heating, which means fewer carbon emissions going into the atmosphere and getting us all hot and bothered.

Plus with the warming climate we’ve inherited, this fabric could help make time spent working and exploring outdoors more tolerable.

So, Can I Buy One?

This material is pretty phresh – the findings on it were only published in Nano Letters at the end of last month. 

BUT the report found that Janus is pretty practical to bring to market. It’s economically sound to produce and can be cleaned in the washing machine. 

So keep an eye out – you could be wearing a T-shirt made of Janus sooner than you think.


Feature photo by Georgia Doherty