Archives for June 2017

A Tale of Two Hobbies: Part 1

When you think of the future of materials science and engineering, you probably don’t think of origami or canning.  Neither would most people.  I, however, know something that most people don’t, the origin of two amazing materials: metamaterials and aerogels.  Due to space constraints, today’s post will just be about metamaterials, but don’t you worry, aerogels are coming right up in the next post.

 

The art of origami has been around for many centuries, and it has not only ingrained itself in Japanese culture, but it has also spread around the world as a hobby.  We’ve all folded a cootie catcher while bored in class, or folded a crane from a piece of scratch paper.  Origami is everywhere, because it is literally the art of folding paper.  Origami has served a symbolic purpose since its inception, but only recently has it become useful in STEM fields.  As maximizing storage space and efficiency become increasingly important, origami has become a welcome solution.  This answer comes via metamaterials.  

 

Metamaterials are materials which get their properties from their structure, rather than their elemental composition.  Metamaterials are important because they can be used in a variety of different settings, as well as in a variety of different patterns.  One particular pattern that has proved particularly useful, especially for maximizing space, is the Miura-Ori.  The Miura-Ori is special because it has a negative Poisson’s ratio, which means that it behaves unlike traditional materials.  Where a sponge, when compressed on two opposite sides, would expand on the other two sides, a metamaterial would contract on all four sides.  Similarly, whereas a sponge, when expanded along the y axis, would contract along the x axis, a metamaterial expanded along the y axis would also expand along the x axis.  This property can be useful for a variety of projects, but perhaps one of the most interesting is a NASA mission.  On long space journeys, storage space is at a premium, and so a solar panel which could be used later in the journey could only be packed if it could be stored compactly.  Metamaterials, and specifically the Miura-Ori pattern, enabled the development of one such solar panel, paving the way for future journeys to the furthest corners of our universe.

NASA’s metamaterial solar panel model at its full size

NASA’s metamaterial solar panel model compressed to save space

 

Metamaterials have countless other applications as well.  Another benefit of the Miura-Ori pattern is that one can introduce reversible defects, which temporarily change properties such as compression strength or the way in which a material condenses.  Metamaterials have also been used by researchers at Harvard to create self-assembling robots, which is a great example of the potential that metamaterials have.  As these materials continue to be developed, we can be sure that they will continue to impact our lives.

 

Harvard’s metamaterial being inflated, expanding

Harvard’s metamaterial demonstrating its range of motion

Thank you so much for reading, and I look forward to presenting more intersections of history, MATSE, and anthropology in the future.

 

P.S. Don’t forget, today’s post will be continued next week in “A Tale of Two Hobbies: Part 2”.

Bridge Over Troubled Water

We drive on them, we walk on them, we even ride our bikes over them, and yet as we pass them on our daily commute they fade into the scenery like so many oak trees.  These valuable mechanisms have been around since the Mesopotamian society, and they provide the quickest means to get from one location to another in many places around the globe.  Cities like Venice and Pittsburgh are famous for these structures. Without them, crossing a body of water would be impossible without a boat.

 

The structures I am referring to, of course, are bridges.  Bridges can be made of numerous different materials; rope, wood, or stone, for example.  In this entry, however, I am going to discuss some bridges with one things in common: iron.

 

It all started with an Englishman named Abraham Darby.

Abraham Darby

 

Cast iron was difficult to produce, and the charcoal needed made the material cost prohibitive.  One day, Darby decided to try using coke (a byproduct of burning coal) instead, and an easy to produce, cost-efficient cast iron was born.  Darby’s contribution did not end there, however.  With economically feasible cast iron available, the architect Thomas Farnolls Pritchard decided that he would build a bridge across the Severns River, one of the most crowded rivers in England. Before he could see through the bridge’s construction, though, Pritchard died, and Darby’s grandson took over the project.  The bridge, simply called Iron Bridge, was the first of its kind, drawing visitors from all over the world.  Its great historical significance has protected it through the years, and today it is a UNESCO Heritage Site.

Darby’s Iron Bridge in England

 

Our next bridge takes us to Canada, to the home of Anne of Green Gables, Prince Edward Island (PEI).   As you may or may not know, the soil in Prince Edward Island contains a unique variety of chemicals which produce world-class potatoes, different than any other potatoes available on the market.  Their potato industry alone is worth a billion dollars annually.  

Special potatoes from PEI

 

The special element in their soil?  You guessed it: iron.  The only problem was that all that connected PEI to the mainland of Canada was a ferry, which naturally was not extremely practical for shipping potatoes.  The solution: a bridge of monumental proportions, the only one of its kind in the world, that would cross ice covered waters so that PEI would have a constant link to the mainland.  

The Confederation Bridge, stretching from PEI to mainland Canada

 

This bridge is called the Confederation Bridge, and its primary material was steel.  Which is composed mainly of (yes, you guessed it!) iron.  The bridge was a massive success, and after its opening in 1997 potato production and shipment have increased dramatically.

 

The fact of the matter is, bridges get you where you want to go.  Whether historical or modern, bridges can be analyzed by their chemical composition, the time in which they were built, or even by their reasons for being.  Materials science, history, and anthropology go hand in hand, because each of them is present in nearly everything any society does.  I look forward to bringing you future installments of this blog, because I really do think that this particular combination of fields is fascinating.

 

Thanks for reading and see you next time!

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