Monday, November 30, 2020

The surprising strengths of materials in the nanoworld | Julia Greer | TEDxCERN



And back to the TEDx talks...

I almost got distracted by the idea of vacuum balloons - filled with nothing instead of helium. That's a brilliant idea.

Then there's the Ashby chart for strength vs density which kind of looks like the Very Hungry Caterpillar. 

More importantly here is the chase for a material that is lightweight (low density) and strong, leaving the main area of the aforementioned Ashby chart.

I think I have most of the concepts down until - for about thirty seconds at 9:35 - the speaker talks about two-photon lithography and how the ceramic matrix is produced. There are words like boxel (a 3d pixel) and rastering lasers through space. I get the bit about depositing the material - whatever it is - onto the polymer matrix, but how the heck that polymer architecture is laid down is a total mystery to me.

All in all this looks like fascinating steps forward toward...something...in the future.

Monday, November 23, 2020

Waste Land - NPR article

Source - https://www.npr.org/2020/09/11/897692090/how-big-oil-misled-the-public-into-believing-plastic-would-be-recycled

I will admit that I am 100% confused by recycling at this point.

I think I can recycle paper, cardboard, glass, and aluminum pretty well. 

I take my aluminum cans to the local animal shelter where they supposedly make some cash from them.

I put my glass, paper, and cardboard (after tearing out the plastic windows in envelopes and tearing off as much sticker waste from the cardboard as I can) into my curbside bin.

But the plastics mystify me.

My local waste collector - Rumpke - says they can take, "Plastic Bottles (empty, crush, reattach lid): Bottles and jugs that have a small mouth and wider base, such as milk jugs, soda bottles, laundry detergent bottles, water bottles, shampoo bottles and contact solution bottles".

When I called them a couple of years ago and asked what they could take, the customer service person - clearly reading from a manual because she couldn't answer follow-up questions - told me they could take "#1-7 except butter tubs." 

#1-7 is pretty much everything, and I know flatly that they can't take styrofoam (foamed polystyrene - #6).

And now I see that Planet Money has posted a twenty-four minute story (audio and transcript - there's also a 4-minute summary from NPR) relating the history of the Resin Identification Codes (RICs) and the plastics industry's efforts in the 1970's to advertise their way out of plastic's imaging problem. Instead of finding ways to recycle plastics, they convinced us to feel better about plastics by letting us think they were making recyclable products.

Which was apparently crap.

But now they've promised that they're really going to recycle plastics going forward.

SULLIVAN: These days, Larry [Thomas, former president of the Society of the Plastics Industry] spends a lot of time biking past the ocean. He's become deeply worried about its future, what it will look like in another 20 or 50 years, long after he's gone. And he thinks back to those years he spent at fancy hotels and conference rooms with oil and plastic executives. And he says what occurs to him now is something he says maybe should've been obvious all along. He says what he saw was an industry that didn't want recycling to work. Because if the job is to sell as much oil as you possibly can, as much virgin oil as you possibly can, any amount of recycled plastic is competition. 
THOMAS: They were not interested and still aren't interested, as far as I'm concerned, in putting any real money or effort in the recycling because they want to sell virgin material. Nobody is producing a virgin product and wants something to come along that is going to replace it. Produce more virgin material - that's their business. Every year, they want to say they produced X number of million more pounds because that meant their business was growing. 
SULLIVAN: And it is growing. We're making more plastic, buying more plastic, using more plastic. That's not going to go away anytime soon. But as the industry dusts off their new ads and makes their new promises, there is one difference. The difference this time is whether or not the public will still believe them.

Monday, November 9, 2020

Many Moving Magnets Melting Metal



Ooh, alliteration! I do love some alliteration.

I also love seeing a low tech version of high tech things - like in this case a bunch of magnets stuck to a moving flywheel being used to melt metal similarly to how an induction coil can melt metal - even metal that doesn't normally respond to magnet.

Monday, November 2, 2020

Shape-Morphing Smart Materials; The Future of Assistive Technology | Mark C Ransley | TEDxUCL



That's a fascinating idea - wearing a suit of materials that could stiffen, expand, and contract with the application of electricity. Memory metal does seems fairly well a natural for that. Interestingly, the talk never mentions them.

I appreciate the speaker's sense of humor as he goes through each of the other options
  • dielectric polymers - perfect except for needing "tens of thousands of volts to operate...enough to give you a pretty nasty electric shock" (4:46)
  • carbon nanotube aerogel - perfect except for also needing tens of thousands of volts to operate
  • nylon fishing line muscles - relies on heat, much faster to heat up (and contract) than to cool down (and release)
  • solid state actuators - either fast or strong but not currently both
  • architectured materials - the current choice of the speaker's research group
The use of computer simulations to design materials - 3d printable structures - to predict the flexibility and changing shape of the material is really interesting.

And I'm amazed that the research group is looking at 3d printed materials - assumedly polymer materials - was the outcome. 

I'd very much like to see larger version of the materials that the speaker demonstrates (much too far from the camera) at 11:45. It's made from laser sintered nylon.