Tag: nano

Black Metal

The huge increase in light absorption enabled by Guo’s femtosecond laser processing means nearly any metal becomes extremely useful anytime radiation gathering is needed. For instance, detectors of all kinds, from space probes to light meters, could capture far more data than an ordinary metal-based detector could.

why are materials science articles often so stupid? the prospect of perfect absorption in metals is exciting for sensors though. not to mention the catalytic possibilities.

Metamaterial

A metamaterial allows special optic properties, such as exceeding the diffraction limit, building cloaking devices, etc
2012-12-10: Materials science really is the unsung hero of most of our prosperity.

A new material created by Cornell researchers is so soft that it can flow like a liquid and then, strangely, return to its original shape. Rather than liquid metal, it is a hydrogel, a mesh of organic molecules with many small empty spaces that can absorb water like a sponge. It qualifies as a “metamaterial” with properties not found in nature and may be the first organic metamaterial with mechanical meta-properties.

2014-01-12: Analog computers

shining a light wave on one side of such a material would result in that wave profile’s derivative exiting the other side. Such analog computers would be much faster and energy efficient than DSPs.

2014-02-10: This is easily the most impressive nanotech demo I have ever seen.

Extremely strong yet ultra-light materials can be achieved by designing nano structured hollow lattices which promise superb thermomechanical properties at extremely low mass densities (lighter than aerogels)

2015-12-01: 1000x 3D imaging resolution

MIT researchers have shown that by exploiting the polarization of light — the physical phenomenon behind polarized sunglasses and most 3D movie systems — they can increase the resolution of conventional 3D imaging devices as much as 1000x. The technique could lead to high-quality 3D cameras built into phones, and perhaps to the ability to snap a photo of an object and then use a 3D printer to produce a replica. Further out, the work could also abet the development of driverless cars.

2021-02-07: Metalenz

Instead of using plastic and glass lens elements stacked over an image sensor, Metalenz’s design uses a single lens built on a glass wafer that is between 1×1 to 3×3 millimeter in size. Look very closely under a microscope and you’ll see nanostructures measuring one-thousandth the width of a human hair. Those nanostructures bend light rays in a way that corrects for many of the shortcomings of single-lens camera systems. The resulting image quality is just as sharp as what you’d get from a multilens system, and the nanostructures do the job of reducing or eliminating many of the image-degrading aberrations common to traditional cameras. And the design doesn’t just conserve space. A Metalenz camera can deliver more light back to the image sensor, allowing for brighter and sharper images than what you’d get with traditional lens elements.

2022-01-30: Not sure about “soon”, but

Imagine a camera that’s mounted on your car being able to identify black ice on the road, giving you a heads-up before you drive over it. Or a cell phone camera that can tell whether a lesion on your skin is possibly cancerous. Or the ability for Face ID to work even when you have a face mask on. These are all possibilities Metalenz is touting with its new PolarEyes polarization technology. Polarization imaging equipment has typically been bulky and expensive, but the PolarEyes system is compact and cost-effective enough to replace a smartphone camera.

2022-04-15: Nice overview of metamaterial capabilities and progress.

Metamaterials’ precise shape, geometry, size, orientation, and arrangements allow them to manipulate electromagnetic or mechanical waves, such as light or sound, by blocking, enhancing, and bending the waves. Their potential applications are multiples, including power transmission, energy harvesting, wireless charging, thermal management, and acoustic applications, Lidars, radars, superlenses for medical devices, AR displays. Electrical engineering, electromagnetics, classical optics, solid-state physics, microwave and antenna engineering, optoelectronics, material sciences, nanoscience, and semiconductor engineering are all involved in the metamaterial field’s advancement.
Metamaterials are impacting several industries: Infrastructure (Thermal management, Acoustic management – vibration and noise control, Seismic metamaterials), Power and Energy (Energy harvesting, Power transmission, Wireless charging), Electronics and Sensors (Lidars, Super lenses for medical applications, Programmable metamaterials, AR displays), Telecommunications (MmWave antennas, 3D radar, Holographic beamforming).
Since the first metamaterials product went to market in 2009, relatively few products became commercially available because the difficulty in designing metamaterials structures and their high manufacturing cost made them prohibitive for commercial applications. In the last few years, improvements in the software for design and simulation in additive manufacturing made the near-term scale adoption of metamaterials-based products possible. Sectors like automotive, telecommunication, and consumer electronics are ripe for disruption. Once metamaterials options reach the market, the conventional products will suffer and likely become obsolete. The metamaterials products don’t require high CapEx because they rely on conventional materials and manufacturing processes with innovative design. When considering a new investment opportunity or starting a company, keep in mind that companies such as Intellectual Ventures have aggressively acquired strategic patents and launched several spin-offs, including Kymeta, Pivotal Commware, and Echodyne. Intellectual property in this field is strategic for the survival of incumbents. Early patents are expected to expire between 2024-2028, and more companies will likely pop up in analogy to what happened in the 3D printing industry in 2005. Exciting times lie ahead to transform many industries with metamaterials products.

2023-08-07: Metalenz explainer video

Against Diamonds

Stupid kills. In this case, being uneducated about the various states of carbon

Adding to the pot-stirring that De Beers and others incited, a single page ad appeared in Variety a few months ago, paid for by the Kalahari Bushmen of Botswana, who were driven from their land by the government to make way for diamond mining. Their ad directly addressed DiCaprio, asking for help which then came in the form of several Survival International advocacy efforts.

2008-02-20: Finally a situation where the diamondoid surfaces warning sign makes sense.

Designer Wong makes engagement rings that can kill you. The razor-sharp diamond point is set into the ring so it can’t get knocked out when you smash someone’s face in, and the edges of the ring are really soft so it won’t cut into your skin during the pounding. It’s romantic because it means, “Will you marry me” but it also means, “I can’t always be there to protect you so if some jerk won’t stop bothering you, puncture him with this.” The diamond sharp edge will also cut skin down to the bone (with a minimum 1 karat stone – but the larger the better). Or it may simply be used to tag hard surfaces, like cars and windows for S.O.S. messages or that last will and estimate when pen or paper (or lawyers) aren’t conveniently around.


2008-06-16: Extremely cheap diamonds will hopefully do away with the “diamonds are forever” crap this country’s brides are infatuated with.

“This is a virtual diamond mine. If we were in Africa, we’d have barbed wire, security guards and watch towers. We can’t do that in Massachusetts.”

2008-10-27: Can’t wait for those to be done in volume, and the retarded engagement ring industry to die.

The most exciting aspect of this new annealing process is the unlimited size of the crystals that can be treated. The breakthrough will allow kilocarat diamonds of high optical quality

2012-09-18: That’s a lot of engagement rings. Diamond rings are now even more broadcasting your status as an idiot to the world.

Russia has just declassified news that will shake world gem markets to their core: the discovery of a vast new diamond field containing “trillions of carats,” enough to supply global markets for another 3 ka.

2015-01-07: No more Diamonds, with the exception of the engagement ring nonsense, of course.

Even my own diamond-business owning, non-millennial father is turning away from jewelry when it comes to gift giving. Sure, he’s made my mom a handful of statement pieces over the years, but at the same price point, he’s more likely to gift something that has actual purpose, aside from aesthetic value. The last few birthdays and Christmases have yielded vacation getaways, iPhones of every generation, even a smart home thermostat. What hasn’t shown up under the Christmas tree in the last 5 years? Diamond anything.

2015-03-18: Diamond scams

We were called hip-pocketers, because we lived from one deal to the next: Your business could fit in the wallet in your pocket. You bought a used Rolex at a pawnshop for $1000 from the kid who’s just paid $500 for it, hurried it over to your watch guy to hit it on the wheel and make it look new, replaced the old worn buckle with a South American counterfeit for $50, and resold it to your friend who owned the jewelry store a few blocks over for $2200, $2275 if she wanted a counterfeit leather box. She could retail it the same day for $3500. We “worked the float” back then, in the ’80s and ’90s—that meant the few days you had between when you paid for something with a check and the check actually hit your bank account. If you flipped the gold you’d bought with a check the same day, you had a few days of free money. Of course, you tried to make money on every deal, but often you were moving so fast that you had to lose money here and there, waiting for the bigger score that ought to come if you just kept hustling fast enough.

On the icky details of this criminal hustle

I’ll tell you how it’s done. Let’s say you have a 14-karat gold ring that weighs 15 grams. First you weigh it and show the customer that it’s 15 grams. “Now we multiply that by 14 for 14 karat and divide it by 24 for 24 karat, which is what it would be if it were 100% gold,” you explain to the seller. “That gives us the price for your 14-karat gold. Multiply that by 15, for 15 grams. Now, 14 karat is 56% gold and 44% base metal, which burns off at the smelter, so we multiply that by 0.56. Finally, we deduct 10% for the smelter, and 15% for my profit. Most gold buyers will charge you 20 or 25%, which is a reasonable profit margin, but we do such high quantity of gold-buying here that we can afford very low margins. That gives us a final figure of…” You get the picture. The customer’s ring is worth $280 in real gold value. But you just offered $120, with a seemingly sound mathematical justification. And you’ve left yourself plenty of wiggle room if they want to haggle your profit down from 15% to 10% or even 7.5%. The real key to this scam is that you’ve deducted for the impurity of 14 karat not 1x but 2x: first, when you calculated the per-gram price and again when you “deduct for the base metal.”

2016-06-07: Time for a 1M carat synthetic diamond to end this silliness

Lesedi La Rona could, if skillfully cut, yield an even larger stone—the largest polished diamond in history. He described the Lesedi La Rona, a single piece of rough some 3 ga old, as “almost ungraspable.”

2023-05-06: It’s happening. Too slowly because people are dumb, but still.

33% of all engagement rings with center stones purchased last year were created in a lab. That’s 2x the number from 2020. As the technology to make lab-grown diamonds has improved, production has increased and retail prices are falling. Their growing popularity, especially among younger consumers, has caught the attention of jewelers and watchmakers — and is challenging traditional diamonds that are mined from the earth.

Air Pollution


Tiles to reduce air pollution in a city, respiratory oases. I love it when architecture solves problems instead of creating them (ie suburbia):

The tiles are coated with titanium dioxide (TiO2), a pollution-fighting technology that is activated by ambient daylight. TiO2 is a photo-catalyst already known for its self-cleaning and germicidal qualities; it requires only small amounts of naturally occurring UV light and humidity to effectively reduce air pollutants into harmless amounts of carbon dioxide and water. When positioned near pollution sources, the tiles neutralize NOx and VOCs (volatile organic compounds) directly where they are generated. They transform previously inert urban surfaces into active surfaces, re-appropriate polluted spaces for safer pedestrian use, and invert problem spaces – dark, polluted, uninhabitable – to benevolent spaces that benefit communities.

2007-01-03: PigeonBlog

PigeonBlog enlists homing pigeons to participate in a grassroots scientific data gathering initiative designed to collect and distribute information about air quality conditions to the general public. Pigeons are equipped with custom-built miniature air pollution sensing devices enabled to send the collected localized information to an online server without delay. Pollution levels are visualized and plotted in real-time over Google’s mapping environment, thus allowing immediate access to the collected information to anyone with connection to the Internet.


2007-09-13: World’s most polluted places as a MyMap.
2014-06-29: US Air Quality Improvement. I like to highlight the occasional good news when it comes to the environment.

Air pollution has decreased even though population and the number of cars on the roads have increased. The shift is the result of regulations, technology improvements and economic change. New York City has seen a 32% decrease in nitrogen dioxide between the 2005-2007 and 2009-2011 periods.


2014-11-26: Pollution can be cleaned up quickly. This should make China’s pledge to improve air quality / reduce greenhouse gases quite feasible.

In 2002, South Korea was ranked 120th for air quality, and 43rd in 2014

2015-09-23: VW 1M tons of pollution. It is time to get tough, and destroy VW.

Volkswagen’s intentional fraud resulted in an extra 1M metric tons of air pollution being spewed into the skies over America; if they’d extended the con to Europe (where there are far more diesels), it would have been orders of magnitude worse.

2017-06-01: Electric Vehicles Are Cleaning Up

In regions that lean heavily on coal-fired power plants, plug-in cars can end up polluting more heavily at the smokestack than gasoline cars at their tailpipes. But as grids get greener, that’s becoming less true nationwide.

2017-06-17: Schlieren Imaging. This is what the world would look like if you could see invisible air currents, temperature gradients, and differences in pressure or composition of the air

2018-01-22: Far UVC disinfection. There’s part of the uv spectrum that kills viruses & bacteria, but does not damage skin.

2018-08-23: Too much CO2 affects sleep

If CO2 can affect sleep quality, that would explain how it could produce a whole-day effect. Strøm-Tejsen tests this on 16 subjects and finds that “objectively measured sleep quality and the perceived freshness of bedroom air improved significantly when the CO2 level was lower, as did next-day reported sleepiness and ability to concentrate and the subjects’ performance of a test of logical thinking.” Good things about this study: subjects were blinded to condition, the paper contains a pilot experiment and a main experiment which mostly replicate each other’s results. Bad things about this study: the experiments were about n = 15 each, the researchers didn’t correct for multiple comparisons, and they admit to manipulating the statistics surrounding their logical reasoning tests to get better results.

2020-08-23: Health benefits of clean air

Ditching fossil fuels would pay for itself through clean air alone. Over the next 50 years, keeping to the 2°C pathway would prevent 4.5m premature deaths, 3.5m hospitalizations and emergency room visits, and 300m lost workdays in the US.

2021-09-28: UV is very effective.

air filtration and UV disinfection can greatly reduce SARS-COV-II in hospital wards. The authors installed portable air filters with UV disinfection on 2 COVID hospital wards in the UK. The air was tested for viruses, bacteria and fungi before the filters were turned on, during the time the filters were on and then again after the filters were turned off. Airborne SARS-CoV-2 was detected in the ward on all 5 days before activation of air/UV filtration, but on 0 of the 5 days when the air/UV filter was operational; SARS-CoV-2 was again detected on 4 out of 5 days when the filter was off.


2022-03-28: 98% reduction in 5 minutes

“Far-UVC rapidly reduces the amount of active microbes in the indoor air to almost 0, making indoor air essentially as safe as outdoor air” The lamps inactivated more than 98% of the airborne microbes in 5 minutes. The low level of viable microbes was maintained over time, even though microbes continued to be sprayed into the room. The efficacy of different approaches to reducing indoor virus levels is usually measured in terms of equivalent air changes per hour. In this study, far-UVC lamps produced the equivalent of 184 equivalent air exchanges per hour. This surpasses any other approach to disinfecting occupied indoor spaces, where 5-20 equivalent air changes per hour is the best that can be achieved practically.

2022-08-19: Startups are entering this space to bring the cost down.

Beam ($5000) is an LED-based, upper room disinfection device that uses 265-nanometer ultraviolet light to create a disinfection zone located above people in a room. Vive ($3000), meanwhile, uses a wavelength known as far-UVC at 222-nanometers to inactivate harmful microorganisms in the air and on surfaces, even while people are present. While the Beam works in large open spaces, like classrooms and office lobbies, the Vive can be installed in smaller spaces, such as conference rooms and bathrooms. “What we have come to realize is that there is not one-size, fits-all for infection protection. What Arc competes with is some form of chemical intervention. For Beam and Vive, it’s HVAC upgrades.”

2022-10-28: Without massive improvements to LEDs, far UVC is not practical due to cost. Unclear what the deal with these startups is but I suspect they don’t output enough power to be effective.

$2000 is a ballpark retail price for a lamp installed by specialists, and the lamps have an expected lifetime of 15 months if they run continuously. There’s hope that far-UV lamps based on LEDs will eventually provide cheaper and longer-lived alternatives to the gas lamps currently being used, but prototype LED far-UV lamps are currently restricted to impractically low levels of power.

2023-09-15: Giant progress in China

China’s pollution levels in 2021 had fallen 42% from 2013. The improvement means the average Chinese citizen’s lifespan is now 2.2 years longer. Chinese cities used to dominate global rankings of the world’s worst air quality; while some are still on those lists, in many cases they have been overtaken by cities in South Asia and the Middle East. In 2021, Beijing recorded its best monthly air quality since records began in 2013. There is still work to do as China remains the world’s 13th most polluted country. And Beijing’s particulate pollution – the tiny but highly dangerous pollutants that can evade the human body’s usual defenses – is still 40% higher than in the most polluted county in the United States.

2024-05-08: What’s needed to make far UVC viable

Light in the 200-235 nm range, or far-UVC, is one of the most promising tools for dramatically reducing airborne transmission from day one of almost any pandemic caused by airborne pathogens. If adopted widely, it could also have a dramatic impact on seasonal flu, colds, and endemic COVID-19.

Unfortunately, progress on development and adoption has been much slower than one would have hoped. One bottleneck is the high cost and low efficiency of the only commercially available source at this wavelength range, 222 nm krypton chloride excimer lamps. For example, by our calculations, equipping a classroom with far-UVC would cost >$10k/classroom/year in lamps alone.
While directly supporting solid-state far-UVC R&D to accelerate availability is important, growing the far-UVC market in general and enabling greater private investment is even more critical.