The Future of Eye Exams

In recent years, a series of portable medical devices has been revolutionizing healthcare and medical treatments in rural, developing countries. The latest innovation that’s generating buzz? Your smartphone.

A team of doctors from London’s Moorfields Eye Hospital have developed a solution to help crack down on eye disease in rural areas of countries like Kenya. Through a simple smartphone app and low-cost adaptor, Peek enables professional eye examinations to be conducted anywhere in the world.

According to Peek’s creator, Dr. Andrew Bastawrous, 39 million people are blind, but 80 percent of this blindness could be avoided if people in rural regions had access to proper eye care. It’s often easy to treat with something as simple as a pair of glasses or cataract surgery, but too often afflicted people are beyond the reach of a basic eye exam.

The Peek system is as easy as taking a photo – the adaptor slips neatly over the built-in camera on a smartphone, and when used with the Peek app, can perform a series of eye exams with the click of a button. This eliminates the need to lug around traditional ophthalmoscopes and other pieces of bulky equipment that also require a stable power supply – something hard to come by in the developing world.

Eye Exam

 

Through these high-quality images that are comparable to pictures taken with traditional equipment, eye examiners can view cataracts closely enough to detect signs of glaucoma, macular degeneration and signs of nerve disease.

As researchers continue to develop low-cost, innovative medical tools like this, it is important to think about durability and functionality of the materials used in the device itself. When testing eyes, a clear, scratch-free lens is necessary to ensure the accuracy of the diagnosis. Additionally, these devices will be used in rural locations where the chance of scratching or breaking a lens is high.

Many smartphone manufacturers have already made the switch to sapphire camera lenses in order to improve durability and performance. These lenses are virtually scratch-resistant and will not show wear and tear the same way a traditional glass lenses will.

In fact, sapphire is already being widely used in the medical field, specifically in surgical tools, implants and in a variety of windows for medical equipment such as endoscopes and laser windows. We truly believe that sapphire could play a large role in the success of these eye exams and would encourage doctors planning to utilize a tool like this to consider what their camera lens is made of.

5 Non-LED Uses of Sapphire

Rubicon Technology may be best known as the worldwide market leader in sapphire for LEDs, but the company’s sapphire is being used in applications far beyond the lighting industry.

From semiconductor equipment components to camera lens covers, there are many intriguing uses for optical and non-wafer sapphire. Here’s a peek at five non-LED usages for Rubicon’s synthetic sapphire.

Rubicon1. Semiconductor Equipment  Components

More than 40 different semiconductor equipment components are made of sapphire. Due to its ability to withstand very high temperatures, extreme environment processing and harsh chemicals like fluorine plasma and many acids, sapphire is ideal for equipment such as plasma tubes, heater plates, lift pins and chamber windows.

2. Medical Component

Sapphire products are used in a variety of medical applications, including dental braces, surgical blades, laser delivery windows, arthroscopy lenses and skull pins. When compared with traditional metal alternatives, medical sapphire components provide advantages of optical transmission, transparency for both aesthetic and performance improvements, high durability and precision, and also can be utilized for procedures requiring active imaging as sapphire does not impact imaging processes like metal.

3. Infrared (IR) Windows

Sapphire windows of optical quality are already being used for military sensing applications on aircrafts and missiles. In fact, sapphire IR windows are now beginning to be used on private, commercial and cargo aircraft to assist with landing in inclement weather.

4. Wafer Carriers

Sapphire is so durable that it is actually used to support other brittle wafers that are being processed, such as gallium arsenide and silicon carbide. These brittle wafers are mounted to sapphire so they do not break or get damaged during transit.

5. Durable Lenses and Windows

One of the largest optical applications for sapphire is in the form of lenses and windows. Due to its hardness and wide range of transmission from UV to Visible to IR wavelengths, sapphire lenses and windows are ideal for use in applications where there is a possibility of impact, scratching, high temperatures, chemical interaction or other harsh conditions. These lenses and windows are used in a wide variety of applications, such as camera lenses, military rifle scopes and as windows for sensors and laser transmission.

We are just scratching the surface when it comes to optical and non-wafer uses for sapphire. As research continues and new applications are discovered, you will see sapphire included in different types of products. Who knows, you may soon be seeing sapphire used for the armored windshields of military vehicles or even in hip replacements!

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.

 

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

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

Sapphire Quality Matters: Part 1

Sapphire is an extremely versatile material with a growing list of applications in a wide range of industries.  Sapphire suits optical applications because of its scratch resistance and its transmission characteristics.  You’ll find sapphire components such as lenses and windows in medical equipment, lasers, satellites, aircraft, flame detectors, smart phones, cameras and watches.  Recent advances in sapphire crystal growth technology and fabrication have improved the performance, purity, and availability of sapphire for all types of applications.

Recently, Novus Light Today published an article by Dr. Jonathan Levine, Director of Technical Business Development at Rubicon Technology, about sapphire quality.  His article gives a thorough review of the measures of sapphire quality for optical applications.  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.

The effects of these variables in the final product are commonly quantified by three metrics: chemical analysis, X-ray rocking curves, and optical transmission.  Additionally, the observance of bubbles in the crystal provides a baseline from which crystal quality is determined because bubbles serve as scattering centers for any light transmitted through a sapphire optic, thus reducing its performance.

This week, we look at the first two metrics, chemical analysis and X-ray rocking curves.

Powdered aluminum oxide

Powdered aluminum oxide

 

 

 

 

 

 

Purity of the crystal is highly important.  According to Levine, the presence of certain elements can vary drastically between suppliers, and sapphire manufacturers must exercise proper quality control.  For example, titanium (Ti) and chromium (Cr) impurities can result in pink crystals.  In nature, these impurities lead to rubies and other variations of sapphire depending on the impurity.  Levine says trace amounts of these elements must be kept below 1 ppm.  Levine includes a graphic about other elements that can cause issues including silicon (Si), potassium (K), chlorine (Cl), iron (Fe), lithium (Li), and sodium (Na).  The data was collected using glow discharge mass spectroscopy (GDMS).

Typically, a company can buy two types of raw material for crystal growth that can have impurities.  Levine says it can be purified alumina powder and/or Verneuil sapphire.  Rubicon has developed a new in-house purification process that converts the raw powder into densified pellets for crystal growth without an increase in cycle time or decrease in crystal yield. This process enables Rubicon to eliminate impurities in the alumina power that they use to make crystal.

Levine includes another useful metric for analyzing sapphire, rocking curve data obtained via X-ray diffraction.  A rocking curve helps measure various stresses in a crystal.  Levine says the width of the resulting peak is highly sensitive to strain and defects within the crystal.  A narrow peak, indicated by its full width at half maximum (FWHM) measured in arcseconds, signifies a high quality crystal free of low-angle grain boundaries and lattice strain.  A standard narrow rocking curve for Rubicon’s ES2 sapphire windows is shown below.

Sample rocking curve data from Rubicon ES2 sapphire.

Sample rocking curve data from Rubicon ES2 sapphire.

 

 

 

 

 

 

 

 

What can introduce a poor rocking curve?  Levine says that high thermal gradients, fast growth rates, and impurities contributed by the surrounding insulation can introduce defects and stress into the crystal that subsequently yield poor results in rocking curve data.  He adds that accurately controlling the temperature gradient and maintaining a stable growth interface throughout the entire process can help make higher quality sapphire.

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

Sapphire Inside: Apple Builds Sapphire Lens into New Home Button, Touch ID

iPhone 5S with the Touch ID includes a sapphire lens

iPhone 5S with the Touch ID includes a sapphire lens on the home button

Today, Apple announced two new models of the iPhone, the iPhone 5S and  the iPhone 5C. One of the biggest news items at the Apple event is that the new iPhone 5S will sport a whole new home button with a fingerprint sensor with a sapphire lens, ringed in stainless steel.

Sapphire, the second hardest material on Earth after the diamond, is scratch resistant, so it should be very well suited for use as a lens. While this is great news for the sapphire community, this is not the only use for sapphire in a smart phone. Many smart phone OEMs already use sapphire for the camera lens cover because of its scratch resistance, but also is used for the LEDs in the backlighting for the screens as well as the silicon-on-sapphire (SOS)-based RFIC chips that power the RF antennas. There are more places for use of sapphire in a smart phone as well since OEMS are looking to use SOS chips for digitally tunable capacitors (DTCs) and power amplifiers. And, don’t forget sapphire’s largest overall market, LEDs, for lighting, displays and more.

Apple claims that Touch ID reads a fingerprint at an entirely new level by scanning sub-epidermal skin layers with 360 degree reading capabilities.  The sensor is part of the home button which is 170 microns thick with a 500 ppi resolution.  Touch ID stores the encrypted fingerprint info securely in a “secure enclave” inside the new A7 chip, the new processor for the iPhone 5S.  The neat thing is that it should be able to store multiple fingers.  The Touch ID will enable you to purchase items on iTunes, the AppStore or iBooks without a password.

You can see where the sapphire is in this photo of the home button from CNet’s live blog of the Apple event:

iPhone 5S graphic illustrates parts of the Touch ID (from CNet)

iPhone 5S graphic illustrates parts of the Touch ID (from CNet) with sapphire

 

 

 

 

 

 

 

The iPhone 5S (and the 5C) go on pre-sale on September 13th and will be on sale in stores on September 20th.

For Further Reading

Engadget, iPhone 5S fingerprint sensor called Touch ID, recognizes your thumb on the Home button: here’s how it works and what it does, http://www.engadget.com/2013/09/10/iphone-5s-fingerprint-sensor/