Materials

Translucent aerogel bricks could outperform their opaque counterparts

Translucent aerogel bricks could outperform their opaque counterparts
An illustration depicting how the translucent bricks might be used in a load-bearing wall
An illustration depicting how the translucent bricks might be used in a load-bearing wall
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By allowing light to shine through from outside, the bricks could reduce the use (and thus cost) of indoor artificial lighting
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By allowing light to shine through from outside, the bricks could reduce the use (and thus cost) of indoor artificial lighting
A top-down view of one of the bricks
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A top-down view of one of the bricks
The translucent bricks can be stacked and bonded together
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The translucent bricks can be stacked and bonded together
An illustration depicting how the translucent bricks might be used in a load-bearing wall
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An illustration depicting how the translucent bricks might be used in a load-bearing wall
View gallery - 4 images

While glass bricks are effective for allowing daylight into buildings, they're not good insulators and they can't be used for entire load-bearing walls. Such is reportedly not the case, however, with experimental new aerogel-filled translucent bricks.

Six years ago, Dr. Jannis Wernery and colleagues from Switzerland's Empa research group stuffed the cavities in regular hollow clay bricks with a paste made up of aerogel particles. The resulting "aerobricks" proved to have very high thermal insulation properties … but of course, they were opaque.

Now, the scientists have taken translucent silica aerogel granules and used them to fill the voids between sheets of clear glass which are joined together (via epoxy resin spacers) to form a long rectangular box shape.

Once those aerogel-filled glass boxes get sealed up, they can be used as bricks which allow sunlight to pass through while still preserving the privacy of people within the building.

The translucent bricks can be stacked and bonded together
The translucent bricks can be stacked and bonded together

Importantly, the Empa bricks have a measured thermal conductivity of 53 milliwatts per meter kelvin, which the researchers state is "the highest insulating performance of any brick found in the technical literature, let alone on the market."

Additionally, thanks to the manner in which the vertically oriented spacers within each brick are offset from one another, the bricks boast a compressive strength of 44.9 megapascals, which is reportedly "several times higher than clay insulating bricks and brick blocks available on the market." This means that they could be used in the construction of load-bearing walls.

By allowing light to shine through from outside, the bricks could reduce the use (and thus cost) of indoor artificial lighting
By allowing light to shine through from outside, the bricks could reduce the use (and thus cost) of indoor artificial lighting

One drawback of the original aerobricks was the fact that they would be considerably more expensive than traditional bricks. Due to the facts that the translucent bricks could be used in place of windows while reducing heating and lighting bills, however, it is believed that they could be cost-competitive with regular building materials.

A paper on the translucent aerogel bricks was recently published in the Journal of Building Engineering.

Source: Empa

View gallery - 4 images
6 comments
6 comments
Walid Damouny
I can't wait to see how such building materials will be used in architecture. Having a translucent wall with a transparent front door is divine.
josefaber
if sized per the depiction, Incorporating transparent PV components might generate sufficient energy to operate embedded leds providing night lighting.
Tristan P
I wonder what sort of chemicals and unnatural products are used in the recipe?
TechGazer
I don't see why this is superior to regular walls with windows. Aerogel filled glass windows that aren't intended to bear loads would probably be cheaper and have superior properties. I'm also unsure of the longevity of epoxy in load-bearing components; an unexpectedly hot day or a fire, and they'll likely fail.
Bob Flint
Interesting seems a might complex with 4x 1/2" float glass plates bonded with spacers, & filled with aerogel beads. Mechanically & thermally it checks out, how are the flammability ratings, & projectile impact ratings?
Kpar
A very interesting concept. Once the price goes down, I think I can see it in wide use.