If rare earth metals become even more scarce than they are today, the medical device industry could be impacted in a significant way. But according to a paper published in PNAS (via Ars Technica), not much can be done to overcome a shortage of these critical metalloids and metals.
It is a tough situation, because modern electronic devices contain a cornucopia of different materials. For example, a standard CPU for a medical device can contain up to 60 different elements. While many of these elements are plentiful in the environment, some can be very difficult to find in nature.
Rare earth metals have a wide variety of favorable physical properties that make them valuable for use in electronics. For example, many miniaturized speakers (like those in hearing aids) use neodymium to drive the speaker. Others are used for LED screens, memory, GPS receivers, actuators, RF generators and more.
In the medical device industry, rare earth elements are often used for permanent magnets. These are very powerful magnets that are used in MRI imaging systems. Rare earth element permanent magnets are slowly replacing helium-cooled wire coils that generate magnetic fields.
Laser technologies also make use of rare earth metals. For example, neodymium, erbium and holmium-doped yttrium aluminum garnet are often used in solid-state lasers. The PillCam by Given Imaging makes use of zirconium to visualize a patient’s small intestine. In addition, zirconium is used for hemodialysis.
While it may be possible to substitute more-plentiful elements when supplies of a rare earth metal run low, there are 12 elements that are irreplaceable. These include manganese, magnesium, thallium, strontium, yttrium, ytterbium, thulium, dysprosium, europium, lanthanum, rhodium and rhenium.
Yttrium is often used for the development of phosphors. This includes red ones that are commonly used in LEDs and cathode ray tubes. In addition, yttrium can be used for electronic filters, electrolytes, electrodes and superconductors.
While rare earth metals can be found across the world, the equipment and environmental costs of rare earth metal mining can be very high. Because of this, much of the U.S. rare earth metal mining infrastructure has been shut down.
From 1940 until 1990, the United States did mine most of its own rare earth metals. One of the largest mines in the world was Mountain Pass, California. With improved globalization, overseas rare earth mines took hold of world markets.
As a result, China currently holds 97% of the global rare earths market. However, this could change in the future. In response to a shortage in 2010, a number of mining companies are working to increase supply. In addition, improved recycling of used electronics could improve rare earth element supplies in the future. In the near-term, however, there is little the industry can do in the event of a shortage.
