Tech Tuesday 3/27/18 – Materials Edition

Materials make up our world, and what we can do with any given thing continues to be one of the fronts along which science and engineering continue to make great strides. Although one could argue that advances occur so quickly that by the time a new material is ready for mass production, it’s practically obsolete.

Tech Tuesday  3/27/18 - Materials Edition

01 – I guess calling diamonds ‘Ice’ is more appropriate than I thought.

02 – A glass that is better at being a glass than glass is?

03 – Since graphene has proven to be endlessly interesting, what do other 2D elements do?  Don’t worry, graphene is still the king and is getting ready to go to space!

04 – Fish scales as a cheap, safe, and culturally/religiously non-problematic source of collagen for human use.

05 – Using air bubbles to quell hurricanes.  (Yes, air is a material)

06 – When you hear about shape memory alloys being used in airplane wings to change the wing shape, I’m sure the idea that comes to mind is some futuristic wing that can reshape itself like a T-1000.  Not quite, instead, the alloy replaces the heavy electro-mechanical and hydraulic systems that actuate flaps or sweep a wing.  It’s a weight reduction strategy that also decreases the failure modes and maintenance overhead.

07 – Treating wood to make it stronger than steel, and super insulating as well.

08 – You got your metal in my rubber!  You got your rubber in my metal!  We got some strong rubber!

09 – Imagine if every transistor in a CPU was also part of the processor memory cache, or perhaps more accurately, if every CPU was a self contained Neural Network…

10 – A road trip that could certainly end with a BANG!

11 – They mention the obvious problem this could solve, but only talk about the more altruistic applications.  I mean, bleeding control and insulation are cool, but affordable diapers made from biodegradable absorptive materials are a huge win.

12 – Perovskite cells that are getting the lead out (with titanium – so more environmentally friendly, but not exactly cheaper).

13 – Trade-offs, everything is about trade-offs.  (Local volcanic rocks make for more environmentally friendly concrete, as long as you don’t need that concrete to be super strong).

14 – 3D printing titanium parts.  It isn’t so much the material, or the method (3D printing), but rather the optimized shape the method can achieve with the material.

15 – Using fungi to let concrete heal itself.

16 – Water continues to be weird, and wet.

17Bad aluminum can be oh so good.

00Well, duh!



Image by yellow_bird_woodstock Tech Tuesday  3/27/18 - Materials Edition


A Navy Turbine Tech who learned to spin wrenches on old cars, Oscar has since been trained as an Engineer & Software Developer & now writes tools for other engineers. When not in his shop or at work, he can be found spending time with his family, gardening, hiking, kayaking, gaming, or whatever strikes his fancy & fits in the budget. ...more →

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27 thoughts on “Tech Tuesday 3/27/18 – Materials Edition

  1. A real treasure trove this week!

    I always enjoy Tech Tuesday and wanted to let you how much I appreciate all the links.

    Smart materials are fascinating, though I’ve seen a lot of them come and go. Shape memory alloy for airplane wings looks cool, but I’d want back up. Most of those alloys fatigue out of full range use well before standard actuator components would. Self-healing materials are a Holy Grail of sorts and I’ve seen a lot discussed with high hopes. I do love the idea of using fungi in concrete though. Even if it doesn’t actually ‘heal’ the material, blunting crack growth would significantly enhance useful life.

    And the bubble chain to reduce the impact of hurricanes is just cool science. :D


  2. 15 had some wording in it about ‘solving America’s crumbling infrastructure problem’ – but it sounds more like it would help avoid next century’s crumbling infrastructure problem, since the fungus spores have to be mixed into the concrete in advance.

    That seems like a tricky sort of thing to predict – you’re interested in a process that you can’t test in the field without recruiting your unborn great grandchildren to collect the data…


    • There are ways of testing it. Civil Engineering labs most major universities have accelerated weathering and fatigue set ups, and field testing is done on identified strips of road over several years.

      When I was in high school in central Ohio, there was a stretch of state route just north of us that had patches of a number of experimental pavements. The area was ideal since it saw major freeze/thaw, heat/humidity, occasionally flooding, and tons of heavy truck traffic. And yes, there were signs advising that the next two miles were trial pavement, so use caution and stick to the speed limit.


      • Accelerated aging tests would be helpful – but does the fungal spores’ aging & decreased viability accelerate by more or less than the concrete’s crumbling? What about the rate at which it repairs the accelerated damage?

        When the material is dead and expected only to deteriorate seems like a simpler thing than a race between deterioration and recovery, mediated by living organisms.


        • That’s a really good question and one I’d expect a well thought out test program to address. Even with completely dead materials, you have to account for things like viscoelastic effects in accelerated aging, so I’m sure it could be handled.

          I personally doubt the ability of the fungi to provide real recovery here. It’s more a crack stop measure. If you want to extend life or increase toughness, finding a way to blunt and/or turn crack tips in emerging fractures is the go-to method. If in addition to keeping the crack from growing, it provides ‘glue’ between the fracture surfaces, it has potential to add years to concrete. Even if it just limits spalling, it could be worth it.


          • Crack growth is one of those very important topics in structural mechanics that the public is largely unaware of.

            Back when I was hovercraft crew, hull cracks were always a concern, given how fast they could propagate in the AL hull (hovercraft vibrate, a lot, who knew?). We always had a drill on hand with a fully charged battery and a 1/4″ drill bit chucked up. If we spotted a crack in any part of the hull when we were underway, we’d grab the drill, locate all the crack endpoints, and drill them. If it was below the waterline, we’d fill the hole with 5 minute epoxy and get back to the ship quick as we could. The hull techs would weld the crack when we got back.


            • Crack growth is one of those very important topics in structural mechanics that the public is largely unaware of.

              Shows up in all sorts of interesting places, though. Fencing blades break due to microcrack propagation. International fencing competitions require fencers to use blades made of an approved maraging steel alloy, which is much more resistant to propagation. (More expensive as well.) There are some new dual-phase steels that are even better (and even more expensive), but top-level fencers consistently say that blades made with D-P feel weird in use.

              Doing armory work for fencing led me into reading stuff about just how complex a subject “steel” is.


  3. 04 – Fish farming has some externalities that we haven’t quite got our hands around yet. Using wild fish for non-food purposes would be even worse.

    edit – I suppose though, rtfa, if the scales are being thrown away under current practices, this use is a net positive development.


  4. 05 – the problem is that I think hurricanes are Actually Necessary to get the ‘correct’ amount of annual rainfall in places where they are currently common.


  5. 11 –

    “Each cotton aerogel pellet can expand to 16 times its size in 4.5 seconds – larger and more than three times faster than existing cellulose-based sponges – while retaining their structural integrity. The unique morphology of the cotton aerogels allows for a larger absorption capacity, while the compressible nature enables the material to expand faster to exert pressure on the wound,” added Assoc Prof Duong.

    This might have the same problem as the previous generation of super-clotting agents, in that it stops the bleeding, but makes such a mess inside the body that it’s nearly impossible for surgeons to do the follow on work necessary.


    • I think it would depend on the strength of the expansion. Just because something can expand 16x doesn’t mean it will if the volume is constricted. If it can expand enough to staunch the bleeding without adding compressive stress, it’s a win.


  6. 12 – It’s possible that the quantity of titanium required is small enough that it is “abundant”, in the words of the article. Titanium dioxide can be used in quantities small enough yet useful enough that it’s economical as an ingredient in massed-produced food, for instance.


  7. 13 – isn’t this the same sort of the thing that made ancient Roman concrete so super duper? (and that the secret wasn’t ‘lost’, it just couldn’t really be used without Italy’s specific geology?)


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