The US National Aeronautics & Space Administration’s Langley Research Center in the eponymous Virginian township has signed with El Segundo, California-based Aura Systems Inc to develop Aura’s Rainbow piezoelectric material. Aura, which has a patent pending on the process that produces the piezoelectric material, has produced actuators with up to 100 times more movement than previously found in these types of material. Rainbow, which stands for Reduced And Internally Biased Oxide Wafer, is a process where a standard piezoelectric material is baked with secret substances; after this it takes on a disk shape, being slightly bowed, and when a voltage is applied, up to 1mm of motion can be achieved. Normally, piezoelectric material makes only sub-micron movements. A piezo-electric effect is seen in some natural and synthetic crystals which deform under the influence of an electric field, or produce a voltage when subjected to mechanical stress. Under the terms of the agreement, NASA will provide a team of applications engineers and all laboratory and measurement services needed to advance the development of commercial applications of the material. Aura will supply the material and will manufacture all jointly developed applications. The Californian says the development of the material means that there are many applications that are opened that would have needed more complex mechanical assemblies. A first application has produced a prototype fluid pump with no moving parts other than a set of Rainbow wafers. The valve needs no pressure to open and the pumping is provided when voltage is applied to the wafers. The pump is currently undergoing extensive evaluation and testing at NASA to characterise its performance. NASA is particularly interested because of the absence of moving parts and the potential for uninterrupted working in unusual environments. Aura says it is looking at developing flat loudspeakers for computers, especially notebook-sized machines, which will have low power requirements but give sound good quality. Loudspeakers A recent use of piezoelectric material has been by the Epson Corp subsidiary of Seiko Epson Co in its new inkjet printer, the Stylus Color, which uses piezoelectric technology (CI No 2,445). Crystals in the printer head compress during printing to produce an electric charge that drives the ink through jets in the head on to the paper. Under the NASA pact, Aura will remain the exclusive supplier of the material. The company has not released figures on how much it thinks the products will cost when produced commercially but says they will be cost-competitive. It is formulating its marketing plans and says it expects to have speakers on the market by next year. Aura works in the field of actuator technologies and its main area is magnetic speakers. This year, it provided the loudspeakers for the American Academy Awards and singer Barbra Streisand’s concert tour. It has also produced a valve lifter for car engines that does away with the need for a camshaft, making the engine 35% more efficient, cheaper to make and reducing noxious emissions by half. It has contracts with the US Environmental Protection Agency and other government bodies.
