Can you GROW an Opal?

Opals are pretty.

Full stop

And they are incredibly rare and labor intensive to mine.

So why not just make them at home?

All it takes is seven or so months, a fume hood, some ethyl alcohol (purer is better), tetraethyl orthosilicate, ammonium hydroxide, a stirrer, water bath, hot plate, resin, a vacuum chamber, and apparently infinite patience.

I looked into buying them, and even the synthetic ones aren't terribly cheap.

Why Metals Spontaneously Fuse Together In Space

There is nothing cooler than space.

Nothing...

I'm willing to watch just about the most mundane bit of nothing if it's being done in space because nothing happens in space the same way that it happens here on the surface of Earth.

On Earth, two metals put next to each other stay fairly distinct from each other. (I don't want to hear about your dendritic growth causing shorts.)

In space, however, metals spontaneously weld to each other if the metals are in close enough contact because any sort of oxide layer - immediately formed here on Earth pretty much no matter how well we polish the two surfaces - simply doesn't form. As Dr Derek paraphrases from Richard Feynman's lecture, "when the atoms in contact are all of the same kind, there is no way for the atoms to 'know' that they are in different pieces of [metal]." 

Seriously, space is so totally foreign to our experiences.

Nanotechnology is not simply about making things smaller | Noushin Nasiri | TEDxMacquarieUniversity

The scale of nanotechnology befuddles me, but this video focuses more on why the nanoscale matters than it does on 'hey, here's some neat nanoscale stuff'. Yes, there's some neat nanoscale material mentioned toward the end, but the better part of the video for me is the clean, clear progression from 'what is the nanoscale' to 'why does the nanoscale matter' to 'what can we do in the nanoscale'.

Well done, Dr Nasiri.

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.

Vantablack: The Darkest Material Ever Made

That's dark.

That's initial image of the vantablack looks entirely like a special effect.



Vantablack is the lest light-reflective material (coating, really) ever. The video suggests its usefulness inside telescopes, which makes sense. I'm curious, however, where else it could be found useful.

Apparently vantablack is also superhydrophobic.

Material Uses Insect Technology to Stay Dry Under Water

Let's start with the basics, shall we?

In general water is bad for the long-term durability of most surfaces - especially metal surfaces.

Water molecules hold together pretty well. I've even seen (and highly endorse) magnets that show this.

Water molecules have some volume, especially when they hold to other water molecules.

(Now, the tougher step...)

If you can make bumps...pores...posts...something on the surface of a material that leaves spaces too small for water drops (clumps of water molecules) to go into, the surface of the material will stay dry.

Seriously...like forever dry...not from a coating that will eventually wear off...permanently dry (or at least for four months as the early research shows)...

Left column: (top) Polymer/HFS (NC1) composite coating on aluminum substrate, (bottom) silicon square microposts. Middle column: (top) zinc oxide nanorods on silicon substrate, (bottom) silicon nanowire forest. Right column: (top) silicon microgrooves, (bottom) silicon nanograss.

See those scanning electron micrographs (SEM) above? They're from an article on Nature's website. Each surface was tested to see how long it would resist being wetted when immersed in water (then in water that had been thoroughly degassed - to make sure it wasn't gas bubbles being trapped that resulted in the lack of wetting).

Left: Wetted surface with 25 μm pillar spacing. Middle: Wetted surface with 5 μm pillar spacing. Right: Dry surface with sub-micron pillar spacing. Abbreviations: Frozen water (H₂O), Silicon substrate (Si)

And there you can see their results. Make the pillars wide enough to leave 25 microns of space, get a wet surface...5 microns, still wet...less than one micron, dry...forever dry...perfectly dry.

There's a nice summary of the article on IFLScience's website, but you do, as always, run into the issue of that F in the web address...

This 1,600-Year-Old Goblet Shows that the Romans Were Nanotechnology Pioneers

The Romans were genius.

The had the baths, the vomitoria, the toga parties, the aquaducts, the fingers.

And they had goblets that change color as light went through them and as different liquids are filled into it. In fact, the science is pretty stunning...

researchers in England scrutinized broken fragments under a microscope and discovered that the Roman artisans were nanotechnology pioneers: They’d impregnated the glass with particles of silver and gold, ground down until they were as small as 50 nanometers in diameter, less than one-thousandth the size of a grain of table salt. The exact mixture of the precious metals suggests the Romans knew what they were doing—“an amazing feat,” says one of the researchers, archaeologist Ian Freestone of University College London.

...

[T]he researchers ... imprinted billions of tiny wells onto a plastic plate about the size of a postage stamp and sprayed the wells with gold or silver nanoparticles, essentially creating an array with billions of ultra-miniature Lycurgus Cups. When water, oil, sugar solutions and salt solutions were poured into the wells, they displayed a range of easy-to-distinguish colors—light green for water and red for oil, for example. The proto­type was 100 times more sensitive to altered levels of salt in solution than current commercial sensors using similar techniques.

Clearly, the lead hadn't kicked in just yet when these goblets were being made.

A Boy and His Atom: the world's smallest movie

On some level this is nothing more than a commercial for IBM.

On some other level, though, this commercial is pretty freaking cool. These scientists, admittedly paid by IBM, used an electron microscope to move individual atoms to then make frames in a stop-motion animated 'movie.'

In terms of materials science, the ability to build materials atom by atom, on a nanotechnology scale, may well be the ultimate destination of materials building, not waiting to see what how the atoms will combine on their own under temperature and pressure.

If only we could work atom by atom to perfect a material.

Ross Nanotechnology Introduction

The imagery here of chocolate sauce just rolling right off of white shoes - a particularly good color choice for the product demo - is stunning. For a brief while I even thought I understood what was happening - clearly the material is a nonpolar compound. Water's polar; anything nonpolar would 'repel' the water.

And then they started dumping oil on the product with equal success. Clearly I have some learning to do before I understand just what makes something super hydrophobic.

NASA: Blacker Than Black

This video gives us a look at how NASA uses carbon nanotubes to produce a surface that reflects an absolute minimum of lightwaves for their optical instruments in space. The video looks at the structure of the nanotubes as well as some of the durability tests that they have conducted to make the nantube coatings more durable.

Ross Nanotechnology Introduction

There's slick and then there's slick.

Ross Nanotech produces NeverWet coating - for which I may just be first in line because it's so cool. They're presented as being super-hydrophobic, meaning that they repel water and any water-based solution - with remarkable efficiency.

A little hydrophobic coating - ScotchGuard and the like - prevents some staining on fabric, but a superhydrophobic coating would make fabrics nearly unstainable - at least from any water-based liquid.