I’m starting to worry that I’m turning into an ostrich.

I’m territorial and ill-tempered. I’m fighting a strange desire to eat shiny objects. And when I get scared, I find myself hiding my face as though not seeing whatever is scaring me will make it go away. And this may or may not be related: I’m developing a strong aversion to light bulbs.

Image courtesy http://www.ostrichheadinsand.com/

A company called Nth Degree Tech may be able to help me out with that last problem. They’re seeking to replace light bulbs with their first commercial product, a two foot by four foot LED light sheet that’s flat and looks like a glowing piece of paper, which they plan to ship to customers for evaluation by the end of the year (Bullis). This is an exciting development, since it would allow lighting designers to get freaky with curved or unusually shaped light-emitting surfaces – at a price point comparable to the current cost of fluorescent light bulbs and fixtures.

Image courtesy Nth Degree Tech

To make their snazzy new lighting material, Nth Degree workers carve up “a wafer of gallium nitride to produce millions of tiny LEDs—one four-inch wafer yields about eight million of them. The LEDs are then mixed with resin and binders, and a standard screen printer is used to deposit the resulting ‘ink’ over a large surface” (Bullis).  They toss down a layer of silver ink for the back electrical contact, add a layer of phosphors that alter the color of the light emitted by the LEDs from blue to various shades of white, and then they slap on an insulating layer that prevents those pesky short circuits that can burn out the LEDs.

The front electrical contact is made with an ink containing invisibly small metal wires, which makes it transparent and allows light through the layer.  The transparent electrical contact ALONE could be the subject of an entire article, since it’s unspeakably awesome. Its awesomeness derives from the fact that it may eventually replace the brittle and often testy indium tin oxide (ITO) sheets that have been used in touch screens and electroluminescent assemblies in the past. ITO can be expensive, it can’t be printed and it’s not at all flexible – it deserves to be made redundant.

Image courtesy Nth Degree Tech

While printing with inks that are comprised of “tiny working LEDs produces much brighter light than depositing powders or thin films of electroluminescent material,” Nth Degree’s light sheets don’t match the best LEDs available today, which emit over 200 Lumens per watt.  The sheets are better than incandescent lights in terms of efficiency, emitting 20 lumens per watt, but they’re not as good as fluorescent lights just yet, which emit 80 lumens per watt (Bullis).

The new design won’t require heat sinks the way current conventional LEDs do because the lights are distributed evenly and in a thin layer, meaning that they do not get hot.  The downside is that the tiny LEDs need a pretty robust power source and as a result, Nth Degree’s first light fixture will be two inches thick despite the fact that the light-emitting surface is thin and flexible (Bullis).  I’m not letting that ruffle my feathers, however, since I’m betting that the whole assembly will get thinner over time.

WU XING:

Filed under FIRE because it lights up!

Cited:

Bullis, Kevin. “Lighting Sheets Made of Tiny LEDs” Technology Review Online. 10/28/11. Accessed 02/24/12. URL.

Image courtesy thenewyorkgreenadvocate.blogspot.com

The Lumenatrix Backlighting System by Duo-Guard aims to remedy at least the energy consumption issue by providing an LED-based architectural lighting system that allows designers to create free standing, smoothly illuminated architectural elements such as walls and ceilings without hot spots.

The Lumenatrix system is comprised of tiles (squares, hexagons, octagons, or rounds that can be custom-fabricated in 2″-12″ depths) supplied individually or in prearranged configurations.  The tiles can be recessed, surface, or pendant mounted, and they’re capable of transmitting daylight, which reduces the cost of a glowing wall during daylight hours.  The tiles are arranged in panels that consist of a structural power rail grid system that provides low voltage electricity to the LEDs.  The lights can slide on the rails to produce specific lighting effects.

Image courtesy thenewyorkgreenadvocate.blogspot.com

Heat sinks allow the system to run at lower temperatures, which theoretically increases the lifespan of the LED bulbs, and with one LED per square foot of illuminated surface, the power consumption of the system can be as low as 1-3 watts per square foot.

Check out the following video produced by Duo-Guard for Greenbuild last year to learn more about the system!

WU XING:

I have filed Lumenatrix Backlighting system under Fire, since it involves lighting.

Cited:

Lumenatrix Site

ARCHITERIALS is a year old now, and like most healthy, well-adjusted one-year-olds it needs to be changed constantly, crawls all over my apartment, and makes strange burbling noises.  No, really – it does.  It’s terrifying.

Over the past year I’ve profiled approximately 65 materials and learned about blogging, bacteria, and biscuits, although I must confess that the biscuts were a side project.  A delicious, buttery side project.  Anyhow, to celebrate the birthday of ARCHITERIALS and the fact that the tagline “Investigating architectural materials since 2010” has finally attained temporal legitimacy, I’ve compiled for this, the 10th day of January,  a list of 10 materials from 2010 that are generally awesome.  I’ve also summarized the awesomeness of each material in a brief paragraph, and I’ve tried to frame each one as part of a larger, sort of big-picture trend in materials science that I’m studying.  Should you click on the links and read the detailed posts about each material for more information? Definitely. 

Finally, thank you so much to those who’ve submitted information, followed, liked, and posted photos over the past year, I appreciate it more than you can imagine!  Keep the materials coming and do tell your friends if your friends seem like people who might be interested in ARCHITERIALS.

Ten Awesome Materials from 2010 and Reasons They are Awesome:

1.  Materials that can be deployed in disasters or used to improve living conditions:  Concrete Cloth

Concrete cloth is a concrete-impregnated fabric that is fire-proof, waterproof, moldable, drapeable, durable and generally fantastic.  Applications include: gabion reinforcement, sandbag defenses, ground surfacing/dust suppression, ditch lining, landing surfaces, formwork, spill containment and landfill lining, waterproofing, building cladding, boat ramps, erosion control, roof repair, water and septic tanks.  Concrete cloth solves problems you don’t even know you have, although nothing can repair your terrible relationship with your mother-in-law.   

2.  Sustainable, non-toxic materials:  Reclaimed Wood and Agricultural Fiber Panels

Kirei Board, Kirei Coco Tiles and Kirei Wheatboard made from the non-food portions (stalks and husks) of sorghum, coconut, and wheat plants.  The agricultural fiber that’s not sold by farmers for use in the manufacture of Kirei board takes up space in landfills or gets burned up and pollutes the air – therefore repurposing it cuts down on that sort of thing.  Sustainable building materials make the planet happy, and a happy planet makes for happy people. 

3.  Biodegradable materials:  Arbofoam

As it turns out, lignin can be transformed into a renewable plastic if it’s combined with resins, flax and other natural fibers. The resulting bio-plastic, called Arboform, can be thermoformed, foamed, or molded via injection machines.  It’s durable and super-precise when it’s cast, and it degrades similar to wood into water, humus, and carbon dioxide. It’s very cool stuff indeed and I’d love it if someone would send me information about a project where it’s been used.  Biodegradable materials cut down on landfill and reduce environmental pollution. 

4.  Thermoplastic/thermoelastic/thermoformed/thermo-etcetera materials:  Chemical Velcro

How could you not get excited about an adhesive 10 times stickier than Velcro and the reusable gecko-inspired glues that many research groups have been trying to perfect that comes apart when heated??!  I have been trying without success to get my hands on some of this to build demountable partition walls for my tiny apartment, and I’m not giving up.  Materials that respond to changes in temperature by changing their behavior or attributes will find widespread application in the future. 

5.  Materials that clean and sanitize themselves:  Liquid Glass

Liquid glass a coating that takes advantages of the unique properties of materials at nanoscale.  It is environmentally harmless and non-toxic, and easy to clean using only water or a simple wipe with a damp cloth. It repels bacteria, water and dirt, and resists heat, UV light and even acids.  According to manufacturers, you can spray liquid glass on everything from wood to seeds to your sneakers.  It could someday replace all the toxic cleaning products you currently use to tidy and disinfect, and it reportedly costs about 8 dollars.  Materials that clean and sanitize themselves cut down on the need for toxic chemicals and pollutants. 

6.  Materials that emit light efficiently:   White LED Lights

White LED lights emit more light than a typical 20-watt fluorescent bulb, as well as more light for a given amount of power. With these improvements, the new LEDs can replace traditional fluorescent bulbs for all general lighting applications, and also be used for automobile headlights and LCD backlighting.  Shedding light on any given subject has never been more efficient.  As we transition to alternative forms of energy we are also looking for materials that emit light without using much energy in the first place.

7.  Nanomaterials:  Gold Nanoparticles

Gold nanoparticles can be used to further increase the efficiency of LED lights.  Researchers have implanted the particles in the leaves of aquatic plants, causing the leaves to emit red light.  Theoretically, the light produced by the leaves could cause their chloroplasts to conduct photosynthesis, meaning that no additional energy source would be needed to power the process.  In fact, the leaves would actually work overtime, absorbing CO₂ at night.  Nanomaterials allow us to intervene in processes like photosynthesis with a previously unheard-of degree of delicacy.

8.  Materials that augment already useful material properties:  Bendywood 

Bendywood is wood that has been pre-compressed so that it can be easily bent by hand.  The tension that forms on the outside of a bend merely returns the plant cells to their former shape, and the wood doesn’t break.  The material is delightfully flexible and pliable.  Bendywood was developed for indoor uses such as furniture, handrails, or curved mouldings, and it shows enormous promise.  Materials like Bendywood amplify the appealing properties of familiar materials so that it’s even easier to use them to our benefit.

9.  Bio-based materials:  Green Fluorescent Protein (GFP)

At the intersection of biology and solar tech, there are jellyfish that produce green fluorescent protein (GFP).  Dripping GFP onto a silicon dioxide substrate between two electrodes causes it to work itself into strands, creating a circuit that absorbs photons and emits electrons in the presence of ultraviolet light.  The electron current (aka electricity) can then be used to power your hairdryer.  I’m completely fascinated by materials that help us to blur the boundaries between biological and man-made machines.

10.  Materials that repair themselves:  Bacilla Filla

Bacilla Filla is a material that patches up the cracks in concrete structures, restoring buildings damaged by seismic events or that have deteriorated over time.  Custom-designed bacteria burrows deep into the cracks in concrete, where they produce a mix of calcium carbonate and a special bacteria glue that hardens to the same strength of the surrounding concrete.  Materials that can detect their own flaws and damage and repair themselves will revolutionize the way we build and think about building materials in the future.

It’s hard to compete with the luminous output of a ball of hydrogen and helium gas 864300 miles in diameter, but it should be noted that sunlight is not without its drawbacks.  It’s nearly impossible to use at night, and the quality of light is affected by everything from cloud cover to latitude.  Fire works indoors and at night for light, but it’s not very bright, often rather smoky, and could potentially rage out of control and destroy one’s house.  Incandescent light bulbs use too much electricity and put out a kind of yellow or light that doesn’t render color the way sunlight can.  They also burn out with irritating rapidity.  And don’t get me started on fluorescents or sodium halide.

Image courtesy http://coolcosmos.ipac.caltech.edu

The solution these days is to use LED bulbs.  They’re adorably tiny, use very little electricity, and they last for ages.  The problem has been that individual LED’s don’t put out enough light to compete with standard light bulbs for everyday interior/exterior use by people living in homes and working in offices.  Researchers from the Nichia Corporation in Tokushima, Japan have developed a white LED that with “a luminous flux of 1913 lumens and a luminous efficacy of 135 lumens per watt at 1 amp – [can] emit more light than a typical 20-watt fluorescent bulb, as well as more light for a given amount of power. With these improvements, the researchers say that the new LED can replace traditional fluorescent bulbs for all general lighting applications, and also be used for automobile headlights and LCD backlighting” (Zyga). 

Image courtesy crunchgear.com

The researchers focused on how luminous the lights appeared as perceived by the human eye (luminous flux), as well as how luminous they were given a certain amount of power (luminous efficacy).  They fabricated three types of white LEDs, “each of which utilized a variety of improvements in device structure to improve their luminosity, or brightness, and reduce their operating voltage” (Zyga).  All of the white LEDs were based on blue LED dies, each coated with a yellow phosphor to widen the emission spectrum.  The blue light emitted from the LED die mixes with the yellow fluorescence from the phosphor to produce white light.  Red phosphor was also added to balance the spectra (Zyga).  The resulting LEDs produce whiter light at lower voltage than ever before.

“The cross-sectional structure of (a) a conventional LED and (b) a new high efficacy LED with the patterned sapphire substrate and ITO contact as p-type electrode, which reduce the optical absorption and improve the extraction efficiency. Credit: Yuko Narukawa, et al.” Via: Physorg.com

The design improvements point to a world where solid-state lighting replaces our everyday light bulbs.  Although the new white LEDs are more expensive than others on the market today (natch) the price can only come down as economies of scale kick in.

WU XING:

I’m filing white LEDs under FIRE, similar to another post I wrote about LEDs that emit green light (which I hope you’ll check out at your leisure).

Cited:

Zyga, Lisa. “White LEDs with Super-high Luminous Efficacy Could Satisfy All General Lighting Needs.” Physorg.com 08/31/10.  Accessed 09/02/10.  URL.

More:

Yukio Narukawa, et al. “White light emitting diodes with super-high luminous efficacy.”J. Phys. D: Appl. Phys. 43 (2010) 354002 (6pp). DOI:10.1088/0022-3727/43/35/354002

Image courtesy http://threexthree.files.wordpress.com   

The National Renewable Energy Laboratory (NREL) has been feverishly designing solar cells for the past 30 years.  Scientist “Angelo Mascarenhas, who holds patents in solar-cell technology, realized that an LED is just the reverse of a solar cell. One takes electricity and turns it into light; the other takes sunlight and turns it into electricity” (Scanlon).  Mascarenhas and his team reversed the solar cell process and used gallium nitride and indium to make a radiant, reliable deep-green LED.  They’re working on developing a deeper red and a lemon-green to combine with blue and the aforementioned deep green to produce an LED with a color-rendering index well over 90 (I assume the scale is 1-100 but I’m sure you’ll let me know).  This means the hue of light coming out of future LED lamps will appear whiter and can be controlled electronically.

Image courtesy www.nrel.gov

WU XING:

Light makes me think of Fire.

Cited:

Scanlon, Bill. “NREL Finds a Way to Give LED’s the Green Light.” Physorg.com 04/05/10. Accessed 04/06/10.  URL.