5 Ways Biology Is Transforming Buildings

Evolution has reached some pretty outstanding solutions to environmental challenges. It's sort of the ultimate in the fail fast philosophy of engineering. Every mutation is an iteration, and natural selection easily sorts out which designs to pursue. And natural selection has come up with some pretty ingenious solutions.

This video goes through five of those natural solutions and how material scientists are trying to mimic those solutions.

• "Sweat gland cement" - looks at cement blends that contain reinforcing fibers and APP-PER-EN. As the temperature of the modified cement rises, the fibers melt (absorbing energy) then the APP-PER-EN foams and releases gasses to put out fires. Weirdly I can't find anything on the web searching for that APP-PER-EN and cement. I'd appreciate a link to more info if anybody can find it.
• "Polar bear heating" - considers the white fur/black skin combination of polar bear coats. The black skin absorbs heat allowing them to maximize the absorption of heat energy, even leaving them invisible to infrared cameras. German scientists are using a similar idea to adjust the thermal absorption of heat energy for passive solar heating.
• "Homeostasis facades" - are based around muscle fibers expand and contract to regulate heat in the muscles. The facades would be two layers of glass with polymer between them that would expand - blocking sunlight - as they heat up and contract - allowing more sunlight in - as they cool.
• "Mantis shrimp cement" - sees Purdue scientists studying mantis shrimp claw material with its linear structure formed in spiral layers that work as crack arresters. The scientists used a 3d printed concrete structure and printed the layers in spirals similar to the mantis shrimp claw material.
• "Fish scale glass" - takes a look at laminated glass being made more similarly to how fish scales overlap each others. They etched two layers of laminated glass and laminated them together with the diagonal layers flipped to create a diamond-like pattern that makes the glass much stronger than leaving the etchings in the same direction.

What *REALLY* happens to 'Recycled' Glass?! - (you might be surprised)

I apologize for the clickbait video and post title today. I didn't write it and am typically loathe to reward anybody who does by pointing out their video.

Today's video tracks us through a glass recycling facility from breaking up the glass, sorting the metal caps and paper labels from the bottles, separating the different colors of glass via optical scanner, and then reusing the glass into glass insulation. 

Every step seems so simple, and the host even points out that human hands rarely touch the glass on the way through the sorting and recycling factory. That's impressive to me.

Explaining the Stress-Strain Curve with a Paperclip

Last week I said I was going to check out what else the Mat Sci Guy had posted, and I found the above video explaining the stress-strain curve 'with a paperclip'.

Again, be warned, his narration is less than exciting, and the level of science can be a little high for at least my students.

But the explanation of how a paperclip can demonstrate the stress-strain curve is really good. He breaks down the elastic and plastic deformation regions of the curve and explains how those changes are different on an atomic level using two-dimensional diagrams while showing that on a macroscopic level with an extra-, extra-large paperclip.

I appreciate him providing the explanation on the macroscopic, symbolic, and particulate levels, something we've seen within the AP chemistry as a recent push.

Oh, and there are fewer corny jokes in this week's video than in last week's. Other than the 'what is a paperclip used for' schtick at the beginning, it's a pretty straight forward video.