What is the strongest natural material on Earth?

Materials like sapphire, diamond, Kevlar and even spider silk are all well-known for their incredible strength.

Now there’s a new entrant into the conversation, and forgive them for being a bit late—they are snails, after all.

A recent scientific study published in the Journal of the Royal Society Interface has declared limpet teeth as the new official strongest natural material on earth. For those not up to date on gastropods, limpets are small sea snails that live in both fresh and salt water and use their super strong teeth to scrape food off rocks.

Limpets

We’re talking tensile strength here, not hardness.  Hardness and tensile strength are fairly different. A simplification would be that hardness is a resistance to scratching while tensile strength reflects a resistance to breaking.

What is it about limpet teeth that make them so strong?

The tiny teeth are made of very thin, tightly-packed fibers that contain the hard mineral goethite. At 1/100th the diameter of a human hair, the ultra-thin fibers create an almost flawless weave that trumps even man-made carbon fibers.

As the author of the study Professor Asa Barber of The University of Portsmouth put it:

“Generally a big structure has lots of flaws and can break more easily than a smaller structure, which has fewer flaws and is stronger. The problem is that most structures have to be fairly big so they’re weaker than we would like. Limpet teeth break this rule as their strength is the same no matter what the size.”

To gauge the fibers’ tensile strength, Professor Barber attached each end of a small piece of the material to a lever and pulled on the sample until it broke. He found that the material had a strength of 5 gigapascals, which is five times the strength of spider silk and even beats out Kevlar. The tensile strength in this case comes primarily from the structure at a macroscopic level, not the same as crystal structure, which is molecular.

In the future, Professor Barber hopes to see the fibrous structures of limpet teeth studied and used by engineers for high-performance applications, such as Formula One race cars and boat hulls.

Until then, the team at Rubicon gives limpets a tip of the hat for having teeth made of the strongest natural material on Earth.

Stephen Colbert

Sapphire Industry Watch – March 13

  • Rubicon CEO Discusses Applications for Sapphire – NBC 5 Chicago: Bill Weissman, CEO of Rubicon Technology, discusses current uses of sapphire in every day applications such as LED lighting and mobile applications, as well as more unique uses like invisible braces and high-end razor blades. As Rubicon continues to experiment with ways to bring sapphire manufacturing costs down, there is enormous potential for new and exciting applications of sapphire in the future.
  • Are LEDs About to Take Over the World? – The Huffington Post UK: Although the first LED light was produced in 1962, it wasn’t until recently that increased sustainability efforts and lowering costs encouraged the widespread adoption of LEDs. From the Empire State Building’s lighting renovation to NASA’s development of LED facials, it is clear we are living in the age of the LED.
  • Auckland’s bridge lit up by 51 thousand bulbs – stuff.co.nz:  In celebration of the city of Auckland’s 175th anniversary, New Zealand’s iconic Auckland Harbour Bridge is being transformed into an interactive art, music and light show for the next six weeks. More than 51,000 LED light bulbs have been synced to music chosen by the public and performances can be watched in-person, and also via live stream on mobile phones and laptops.
  • San Diego School District Uses Prop 39 Funds for Energy Savings – Energy Manager Today: Thanks to $850,000 in funding from Proposition 39, the California Clean Energy Jobs Act, the Del Mar Union School District in San Diego will be replacing current light fixtures with longer-lasting LED light fixtures with occupancy sensors and dimming controls. The school district will also receive a rebate for the LED installations from San Diego Gas & Electric.

Industry Watch — Sapphire at CES 2015

CES 2015 has come and gone and, as usual, we are left with an overwhelming amount of new and exciting products to sift through.

Don’t worry though! If you’re interested in all things sapphire-related coming out of the show, we have you covered.

Here are the biggest sapphire related unveilings from CES 2015:

  • CES2015: Hands On With Huawei’s Ascend P7 – Android Headlines: While Apple may have failed to incorporate sapphire into its new iPhone, Chinese smartphone manufacturer Huawei has had no problem incorporating the material. During CES, Huawei showcased a variety of smartphones in its booth, including phones from its Premium “P” series. This included the new, Huawei Ascend P7, which features a 5 inch display and an optional sapphire faceplate. 
  • Garmin’s fēnix 3 Multisport GPS Watch Keeps Its Active Side Secret – Gizmodo: Garmin’s popular fēnix adventure watch is receiving a facelift this year to make the rugged timepiece look more polished. The third-generation watch is still fully capable with GPS and pre-set modes for various outdoor activities like swimming or skiing, but is now sleeker with a high-contrast color display and a scratch-resistant sapphire face. 
  • Wellograph, the first sapphire crystal wellness watch, gets a new look, more color choices – AppAdvice: The team that developed the Wellograph wellness watch announced an OS update, new color choices and straps at CES. The Wellograph, which is best known for being the first wellness watch to incorporate sapphire into its display, now offers a new OS which will provide users with features such as sleep tracking and body readiness testing. Along with the new features, the watch is now available in pink gold and white pearl.
  • Sony’s Life Space UX makes the smart home look good – Mashable: One of the most buzzworthy terms at CES over the past few years has been the Internet of Things. With beautifully designed devices and appliances, Sony’s Life Space UX gives just a peek at what the smart home of the future will look like. The highlight of the collection is the Symphonic Light, which combines an LED light with a clear glass covering that doubles as a speaker. The LED bulb, which uses sapphire substrates, makes this light not only attractive, but energy-efficient as well. The Symphonic Light streams music from a smartphone or other connected device, and multiple lights can be connected to fill a room with sound.Sony

9 Things You Didn’t Know About Sapphire

It’s no surprise that there’s been recent speculation about Apple’s use of sapphire in the display screen of the iPhone 6. Regardless of whether or not that happens, sapphire is a modern marvel that has interesting applications far beyond the smartphone market.

Rubicon Technology, Inc., has put together a list of things you might not know about sapphire, from the characteristics that make it so versatile to its potential future applications.

Let’s take a look at why sapphire offers so much promise.

  1. Sapphire used for practical purposes, outside of jewelry, is synthetically grown, and then cut and polished, since clear, colorless sapphire gemstones almost never occur in nature. Synthetic sapphire has a similar composition to the gemstone, but is grown under controlled conditions to prevent  internal stresses that can weaken the crystal. Check out a video on how sapphire is made, featured on the TV show “How Do They Do It.”
  1. Speaking of heat, sapphire has a melting temperature of 2030 degrees Celsius — which is 20x the boiling point of water.
  1. Sapphire is the second hardest material on earth behind diamond and is so strong that it’s been effectively used as bulletproof “glass.”
  1. Apple isn’t the first smartphone company to utilize a sapphire face plate. In fact, luxury phone maker Vertu has been using sapphire screens for 15 years. You can also find sapphire onlens covers of certain smartphone cameras and the fingerprint scanner/home button on the iPhone 5S.
  1. Sapphire is the primary material used as the foundation for LED chips, which can be found all around you in products like traffic lights, light bulbs, HDTVs, tablets, computer monitors, gaming systems and mobile phones. The majority of the commercial sapphire produced today goes into LEDs.
  1. In the future, sapphire could be used for a variety of medical purposes, including artificial joint replacements, given that it’s not only biocompatible so it won’t react with the body but also harder and more durable than ceramics and stainless steel.
  1. You may know that high-end watches have sapphire faces given the crystals’ exceptional clarity and scratch-resistant surfaces. Those same reasons are why sapphire is used in the optic heads of missiles.
  1. Sapphire is used to cover barcode scanners, like the ones you see at the grocery store.
  1. The potential uses for sapphire are truly unlimited! Just imagine one day having ultra-strong wine glasses for those of us with the propensity for breaking them.

Sapphire Demystified

A look at Rubicon Technology's sapphire

A look at Rubicon Technology’s sapphire

There has been so much hype and misinformation about sapphire lately, particularly surrounding sapphire covers or faceplates for smartphones, that we thought we’d review some basic info about commercial sapphire.

  • “Sapphire glass”

There really isn’t any such thing as sapphire “glass.” Sapphire is not a kind of glass; it’s a very hard monocrystalline material. The proper way to reference the clear layer of stuff that may soon cover the screen of your smart phone is as a “sapphire cover” or “sapphire faceplate.” Glass is made of silica or sand, and sapphire is made from aluminum oxide. The two materials have very different physical properties. So, glass isn’t really the right descriptor.

  • Sapphire is unbreakable.

Well, no. That’s not really accurate. A thin piece of sapphire can shatter, similarly to glass or a piece of gorilla glass. Sapphire is the second hardest material on Earth (after the diamond). As such, a thin slice of sapphire will shatter. What is sapphire good at? Sapphire is scratch resistant. That’s one of the main reasons why smartphone vendors are interested in sapphire for applications in lenses and fingerprint scanners.

  • Sapphire is blue.
Sapphires come in a range of colors.

Sapphires come in a range of colors. The purest sapphires are clear.

Yes and No. Sapphire, also called corundum, comes in a range of colors. The purest form of sapphire is clear.  Sapphire is a crystal made from Aluminum Oxide (Al2O3). Natural sapphire forms over thousands of years in the earth, but comes in different colors due to impurities such as minerals or other conditions (like humidity or radiation). Rubies are made of aluminum oxide and are actually sapphires. They are red because the crystal contains impurities in the form of the mineral chromium, making the crystal red. Sapphire gemstones get their blue hue from iron and titanium. Yellow sapphires get their color from a combination of iron and radiation (interesting).  The commercial sapphire that’s now being used in consumer electronics is very pure, so it’s colorless.

  • Sapphire in LEDs and smart phones is from blue sapphire gemstones.

No. The sapphire that is used in LEDs and smartphones is grown in a commercial setting using one of few processes – the Verneuil Method, Kyropoulous Method, Heat Exchanger Method, Czochralski Method and Edge-Defined Film-Fed Growth Method. Each method has its differences, but they produce a single crystal of clear sapphire that is fabricated (cut and polished) into a sapphire substrate used in an LED or into a lens or faceplate for optical uses like smart phones.

 

Substrate Update: It’s All About Patterning & Large Diameter Wafers

yole_developpement_logoMarket research firm Yole Developpement recently published a new report on front-end manufacturing trends for LEDs. Their latest report gives us some very good news about the sapphire market. Semiconductor Today reported on Yole’s analysis. Here are some big take-aways:

  • There is increased demand for larger-diameter sapphire wafers, with big players (such as LG, Sharp or Osram) moving to 6” wafers and Taiwanese players moving to 4” wafers.
  • LED chip makers demand more patterned sapphire substrates (PSS). PSS are now mainstream in the market with an 87% share as of Q1 2014.
  • While some companies (such as Soraa and Toshiba) have begun mass production of gallium nitride-on-silicon (GaN-on-Si) and GaN-on-GaN LEDs, market penetration of these alternative substrates will depend on future improvements in terms of performance and cost.  Without these improvements, alternative substrates will not be able to fully compete with sapphire-based LEDs.

What does this mean for sapphire makers? LED chip manufacturers are looking to gain production efficiencies, lower costs, and increase performance for their LEDs.  As the adoption for LED lighting increases, they need to make more and better performing LEDs. Large diameter sapphire wafers enable more throughput for each run of the MOCVD reactor, making better use of the reactor “real estate” and decreasing the cost per unit of area processed. Depending on the type of MOCVD reactor used, LED chip manufacturers using six-inch wafer platforms may achieve up to 48% greater usable area per reactor run as compared to two-inch wafers.

What does PSS offer? First, PSS helps improve epitaxial growth by promoting growth of the GaN in parallel to the substrate surface. This helps reduce the number of dislocations, called the dislocation density, which can degrade performance of an LED.  Secondly, patterning can help extract as much as 30 percent more light from an LED.  This is particularly advantageous for high brightness LEDs (HB LEDs) that are used in LED lighting applications.

LED chip manufacturers have been buying smaller 2-inch and 4-inch PSS from outside suppliers for years.  The next step in the evolution in the market is the migration to large diameter PSS. Already a pioneer in the development of large diameter sapphire substrates, Rubicon Technology has developed capabilities for large diameter PSS making it possible to manufacture 6-inch and even 8-inch PSS. Rubicon is already gaining traction in the PSS market.  The company recently reported in their Q1 2014 earnings call that they received their first order for PSS and have samples out to more than a dozen LED chip manufacturers.

For more information about the report from Yole, visit http://www.i-micronews.com/reports/LED-Front-End-Manufacturing-Trends-report/14/433

For Further Reading

Semiconductor Today, Substrates shaping trends in LED front-end manufacturing, http://www.semiconductor-today.com/news_items/2014/APR/YOLE_300414.shtml

Clearlysapphire.com, Larger Wafers, Larger Yield – The Numbers Behind Large Diameter Sapphire Wafers and Yield, http://blog.clearlysapphire.com/?p=435

Clearlysapphire.com, Large Diameter Patterned Sapphire Substrates Explained, http://blog.clearlysapphire.com/?p=582

Clearlysapphire.com, Sapphire Substrates for LED: The Big Move Toward 6″ Has Already Started, http://blog.clearlysapphire.com/?p=37

Opportunities for Sapphire – A New Look at Smartphones, Tablets and Even Smartwatches

This week, we’ll take a look at smartphones, tablets and smartwatches and the market opportunity that these consumer devices present for sapphire. Sapphire can be used in a number of ways in them ranging from LEDs for the backlighting display and LEDs for the camera flash to sapphire material for use camera lens covers and home button covers. There’s even speculation that they could be used for front cover plates in smartphones.

Recently, smartwatches and “wearables” have become “fashionable” so we’ll take a look at sapphire in smartwatches too. The infographic in this post points to the number of ways that sapphire could be used in smartphones and tablets.

Opportunities for Sapphire: Smartphones and Tablets

Opportunities for Sapphire: Smartphones and Tablets

Let’s take a closer look at the market for smartphones and tablets.  Backlighting has been a very fertile area for LEDs. The market penetration of LEDs in backlighting displays for mobile phones, tablets, LED camera flash and keyboards is nearly 100 percent. But, let’s look at the numbers.

First, 2013 was a groundbreaking year for smartphones. According to market research firm Gartner, smartphone sales surpassed feature phone sales for the first time with smartphones accounting for 53.6% of overall mobile phone sales for the year.  Overall, Gartner says that 968 million smartphone device units out of a total of 1.8 billion mobiles were sold in 2013. Given that there’s an opportunity to sell sapphire for multiple uses in each smart phone, that’s quite a bit of sapphire. And, even feature phones present an opportunity for sapphire in backlighting, camera flashes and camera lens covers.

In tablets, the opportunity for sapphire is in the same applications, but with a twist. Backlighting is a good opportunity with even more display real estate that larger tablet screens represent.  Many tablets also feature a front facing camera and a back facing camera, doubling the opportunity for camera flashes and protective camera lens covers. According to Gartner, worldwide sales of tablets to end users reached 195.4 million units in 2013. Again, that’s a good opportunity for sapphire.

Wearables like smartwatches are an emerging market and a new opportunity for sapphire. As a traditional cover for watches, sapphire is a natural cover for smartwatches as vendors like Samsung, Omate and the Wellograph Wellness Watch already use sapphire covers in their smart watches. JP Morgan estimates that the smartwatch market size could reach US$26 billion by 2018. This is up from less than US $1 billion in 2013. Once again, that’s a good opportunity for sapphire.

For Further Reading

Tech Crunch, Gartner: Smartphone Sales Finally Beat Out Dumb Phone Sales Globally In 2013, With 968M Units Sold, http://techcrunch.com/2014/02/13/smartphones-outsell-dumb-phones-globally/

Gartner, Gartner Says Worldwide Tablet Sales Grew 68 Percent in 2013, With Android Capturing 62 Percent of the Market,  http://www.gartner.com/newsroom/id/2674215

CNet, Wellograph’s sleek new Sapphire Wellness Watch sparkles with style at CES 2014 (hands-on)

http://reviews.cnet.com/watches-and-wrist-devices/sapphire-wellness-watch/4505-3512_7-35833913.html

The Smart Watch Review, Apple Might Have Big Plans for Sapphire and its iWatch, http://www.thesmartwatchreview.com/apple-might-have-big-plans-for-sapphire-and-its-iwatch/

JP Morgan, Smartwatch Market, https://markets.jpmorgan.com/research/email/-pefp7bj/GPS-1320515-0

Large Diameter Patterned Sapphire Substrates Explained

Rubicon Technology offers large diameter PSS in a range range of shapes including cone, dome and pyramid as well as custom.

Rubicon Technology offers large diameter PSS in a range of shapes including cone, dome and pyramid and range of orientations.

While LED chip manufacturers have been using patterned sapphire substrates (PSS) for years, there’s growing interest in large diameter PSS.  Recently, Rubicon Technology announced the commercial availability of large diameter PSS.  During their latest earnings call, they indicated that they’ve received interest from 7 major LED chip manufacturers for 4- and 6-inch large diameter PSS.  Why the interest from LED chip manufacturers?

First, PSS helps improve epitaxial growth by promoting growth of the GaN in parallel to the substrate surface. This also helps reduce the number of dislocations, called the dislocation density, which can degrade performance of an LED.  Secondly, patterning can help extract as much as 30 percent more light from an LED.  This is particularly advantageous for high brightness LEDs (HB LEDs) that are used in LED lighting applications.

Second, the evolution of patterning large diameter substrates brings economical advantages to LED chip manufacturers, especially those anticipating demand from the LED lighting market.  Large diameter sapphire wafers help LED chip manufacturers cut costs by enabling more throughput for each run of the MOCVD reactor.  This helps chip manufacturers make better use of the reactor “real estate” and decreases the cost per unit of area processed because of the curvature of the larger wafer.  The outer curvature of a 6-inch wafer is less, enabling greater use of the surface area than the tighter curvature of a 2-inch wafer resulting in less edge loss.  Larger diameter wafers also provide post-MOCVD efficiencies.  Depending on the type of MOCVD reactor used, LED chip manufacturers using six-inch wafer platforms may achieve up to 48% greater usable area per reactor run compared with two-inch wafers.  These efficiency gains become very compelling when manufacturers want to ramp up LED chip production to support greater volumes of LEDs for light bulbs.

Finally, LED chip manufacturers have been buying smaller 2-inch and 4-inch PSS from outside suppliers for years.  The next step in the evolution in the market is the migration to large diameter PSS for the reasons we mention above.  While some LED chip manufacturers will have specialized patterning needs and the resources to keep the work in-house, others will not.  Some LED chip manufacturers may not have the expertise and equipment to move to large diameter PSS, so having a ready, trusted supplier will prove handy.

For Further Reading

ClearlySapphire, LED Lighting Spotlight: Patterned Sapphire Substrates http://blog.clearlysapphire.com/?p=390

Semiconductor Today, Patterned sapphire for nitride enhancements, http://www.semiconductor-today.com/features/SemiconductorToday_SeptOct_PatternedSapphire.pdf

Compound Semiconductor, New Wet Process For LEDs On Patterned Sapphire Boosts Efficiency, http://www.compoundsemiconductor.net/csc/news-details.php?cat=news&id=19734296

Compound Semiconductor, Rubicon Orders Multiple Profilers For Sapphire Production, http://www.compoundsemiconductor.net/csc/news-details.php?cat=news&id=19735318

Clearlysapphire.com, Larger Wafers, Larger Yield – The Numbers Behind Large Diameter Sapphire Wafers and Yield, http://blog.clearlysapphire.com/?p=435

Rubicon Announces Large Diameter Patterned Sapphire Substrates

PSS with dome shape

PSS with dome shape

 

This week, Rubicon Technology announced the launch of the first commercial line of large diameter patterned sapphire substrates (PSS) in four-inch through eight-inch diameters.  The new product line provides LED chip manufacturers with a ready-made source of large diameter PSS to serve the needs of the rapidly growing LED general lighting industry.

This is doubly important since patterning helps improve both epitaxial growth and light extraction for each chip and enhances a chipmaker’s throughput and efficiency.  Rubicon announced that they have fully customizable sub-micron patterning capability with tight dimensional tolerances, within ±0.1 µm.  Rubicon offers LED chip manufacturers more usable area to maximize the number of chips per wafer due to an edge exclusion zone as small as 1 mm.  Rubicon’s patterning is available in a range of shapes including cone, dome and pyramid, and in a range of orientations.  Further customization of geometry, pattern and orientation is available too.  You can find a brochure about it on Rubicon’s web site here.

Rubicon’s president and CEO Raja Parvez pointed out the importance of large diameter patterned sapphire substrates in a news release.  “As LED-based general lighting gains worldwide adoption, large-diameter patterned sapphire substrates will become necessary to meet the demands of the rapidly growing lighting market.”

Parvez added that the company developed an unmatched technology platform that is vertically integrated from raw material through crystal growth, large diameter polished wafers, and now custom PSS in 4”, 6” and 8” diameters.  According to Parvez, vertical integration enables Rubicon to produce progressively larger sapphire products while providing customers with exceptional quality, cost control, reliability, and consistency.

For Further Reading

Rubicon Technology, Rubicon Technology Launches First Commercial Line of Large Diameter Patterned Sapphire Substrates for the LED Industry, http://bit.ly/1itVMHq

Clearlysapphire.com, LED Lighting Spotlight: Patterned Sapphire Substrates, http://blog.clearlysapphire.com/?p=390

 

Sapphire – Quality Matters, Part 2: Transmission Quality

Recently, Novus Light Today published an article by Dr. Jonathan Levine, Director of Technical Business Development at Rubicon Technology, about sapphire quality.  His article shares a thorough review of the measures of sapphire quality for optical-grade applications.  Last week, we looked at the first two metrics, chemical analysis and X-ray rocking curves.  This week, we’ll look at transmission quality.

Levine writes that the quality of a sapphire is determined by how closely the grown crystal matches the ideal structure with respect to the arrangement of atoms within the lattice, dislocations, defects, and stress.  Root causes for these problems often originate from insufficient purity of the starting material and the growth process itself.

Sapphire exhibits excellent transmission in the ultraviolet (UV) to the mid-infrared (IR) range (~200 – 5000 nm).   According to Levine, conditions within the sapphire growth furnace can induce subtle interactions between the molten sapphire and the growth environment.  These interactions can produce bubbles, dislocations and other stresses that could impact optical performance.   Levine says that carefully controlling the growth environment produces sapphire that maintains excellent transmission at 200 nm through the mid-IR wavelengths.  He illustrates the impact of furnace interactions by comparing Rubicon’s ES-2 sapphire with another commercial sapphire maker’s crystal produced using a different growth method in the figure below.  From the image in the post, you can see a sharp absorption peak at 200 nm for sapphire produced by the commercial maker that is absent in sapphire grown by Rubicon.

Optical transmission of sapphire depicting a sharp absorption peak at 200 nm for sapphire produced by a commercial producer that is absent in sapphire grown by Rubicon.  Inset: Optical transmission for Rubicon sapphire from the visible to mid-IR range approaching 90% due to the high quality of the material.

Optical transmission of sapphire depicting a sharp absorption peak at 200 nm for sapphire produced by a commercial producer that is absent in sapphire grown by Rubicon. Inset: Optical transmission for Rubicon sapphire from the visible to mid-IR range approaching 90% due to the high quality of the material.

For Further Reading

Novus Light Today, Optical-Grade Sapphire, Where Quality Matters, http://www.novuslight.com/optical-grade-sapphire-where-quality-matters_N1596.html#sthash.giGipxT1.dpuf