New Applications for Sapphire: Medical (Part 2 of 3)

rod of asclepiusNew industries are finding man-made sapphire a desirable material. The field of medicine is looking at sapphire for its optical transmission range, durability and chemical inertness for bio-compatibility.

Sapphire’s optical properties and durability offer advantages for specific medical laser applications in dermatology, ophthalmology and dentistry. Sapphire is widely used in surgical systems for its laser transmission, high resistance to heat and non-thrombogenic properties (meaning it doesn’t promote clotting).  It is used as a laser window for endoscope lenses, laser hair removal systems and blood cell counters.  In addition, sapphire products are used for surgical tools, implants, braces.  Sapphire microscalpels are transparent blades that make it easier to visualize and illuminate capillary vessels, nerves, cutting zones and cutting depth compared with traditional metal alternatives.

One area that has potential for sapphire is in artificial joint replacements.  Many joint replacements include metal, ceramic, metal-polymer and ceramic polymer endoprosthesis. This is an area that may develop friction and wear over time causing the joint to fail.  Endoprostheses made of metal and ceramics may interact with the body and also degrade from friction over time.  For example, metal-on-metal artificial hips have a lifetime of 15 to 30 years, but have been known to fail earlier.  Sapphire is attractive for endoprostheses for its bio-compatibility since it is chemically inert and won’t react with the body as well as its low friction coefficient, hardness and durability

For Further Reading

The New York Times, The High Cost of Failing Artificial Hips, http://www.nytimes.com/2011/12/28/business/the-high-cost-of-failing-artificial-hips.html?pagewanted=all

IMS Research/Rubicon Technology, White Paper: Opportunities for Sapphire, Jamie Fox, http://rubicontechnology.com/resources/papers,

Sapphire: Material, Manufacturing, Applications, by E. R. Dobrovinskaya, Leonid A. Lytvynov, V. V. Pishchik. Springer Sciences Business Media, ISBN: 978-1441946737.

New Applications for Sapphire: Aerospace & Defense, Part 1 of 3

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Range of sapphire products available from Rubicon Technology including large optical windows and other shapes for aerospace and defense.

Sapphire’s unique properties make it a perfect material for high-performance applications due to its optical transparency, physical strength, resistance to abrasion and corrosion, temperature durability, chemical inertness, and bio-compatibility. As a result, it is perfectly suited for extreme environments where material durability is just as important as optical clarity.

One extreme use case is in the aerospace and defense industry where there’s a need for rugged windows for targeting pods and missile domes, most notably for the US F-35 fighter jet, that may come in contact with harsh conditions from the harsh, gritty desert with extremely high temperatures to high altitudes with extreme low temperatures.

Market research firm Yole Developpement determined that non-substrate applications for sapphire in the defense, semiconductor and other applications represent 25% of the sapphire industry revenue in a new study.  The market represents a solid growth opportunity for sapphire makers.

While there is opportunity, innovation is needed.  Sapphire traditionally has been limited to smaller shapes and sizes using traditional growth methods.  As sensor technology and applications, in defense and aerospace in particular, have evolved, the size requirements for sapphire windows have grown substantially.  One company that is innovating sapphire crystal growth is Rubicon Technology.

In a recent paper, Rubicon’s Dr. Jonathan Levine, Director of Technical Business Development, detailed how Rubicon successfully produced very large sapphire blanks using a highly modified horizontal directional solidification process. This new method, named the Large‐Area Netshape Crystal Extraction (LANCE) system is currently able to produce crystals of several different orientations. The company plans to produce sapphire windows as large as 36 x 18 x 0.8 inches.

For Further Reading

Clearlysapphire.com Blog, Opportunities for Sapphire: New Applications & Markets Explained, http://blog.clearlysapphire.com/?p=426

Clearlysapphire.com Blog, How Large Can You Go? Sapphire Windows Grow Up and Across, http://blog.clearlysapphire.com/?p=409

Rubicon Technology, Synthesis and characterization of large optical-grade sapphire windows produced from a horizontal growth process, http://www.rubicontechnology.com/sites/default/files/Synthesis%20and%20Characterization%20of%20Large%20Optical%20Grade%20Sapphire%20Windows.pdf

Rubicon Develops New Sapphire Growth Platform to Make Large Optical Windows

Sapphire Windows in Lockheed Martin f-35 Lightning Joint Strike Fighter

Sapphire Windows in Lockheed Martin f-35 Lightning Joint Strike Fighter

There are a lot of ways to make large commercial sapphire crystals.  But none of them really work for making large sapphire windows using sapphire’s a-plane. We mean really wide so that they can be used in a military plane as a targeting system window.  So, the Air Force Research Laboratory (AFRL) asked Rubicon Technology to develop a new growth platform for very large polished sapphire infrared (IR) windows.  The project is supported by a grant from the AFRL, with a total value of $4.7 million over three years.

Sapphire is perfect for military and other high-performance applications due to its hardness and strength, transparency in the visible and IR spectrum, thermal conductivity, thermal shock resistance, abrasion resistance, high melting point and chemical inertness.  The project will begin with intermediate sizes, then will step it up to windows as large as 36 x 18 x 0.8 inches.

Why do we need this new method?  Existing methods used to produce sapphire windows don’t meet the demands of military applications for thickness and size.  Rubicon’s new technological platform will grow panels approximately two inches thick, which can be cut into multiple windows of varying thickness.  The new method also allows growth of very large windows up to 36 x 18 inches. This is an improvement over smaller faceted windows that require piecing together for large applications.

The sapphire windows for the AFRL will be applied to fighter jet targeting systems. For example, the Lockheed-Martin F-35 Lighting Joint Strike Fighter’s fuselage has a durable sapphire window in the fuselage for use by the Electro-Optical Targeting System (EOTS).  The sapphire is preferred due to its durability, hardness and strength and the way it allows transmission light in the IR spectrum.

Links:

Lockheed-Martin F-35 Lightning II Joint Strike Fighter, http://airsoc.com/articles/view/id/4fe4b7f8c6f8fa2443000009/lockheed-martin-f-35-lightning-ii-joint-strike-fighter

Clearlysapphire.com. http://www.clearlysapphire.com/Optical__Lasers_Windows_.html

Rubicon Technology, http://rubicon-es2.com/index.php?page_id=23