Researchers at Scandinavian research organization SINTEF have made progress in developing components that dissolve in water. Printed on a silicon wafer, the components contain extremely thin circuits — only a few nanometers thick — that are designed to transfer energy. They are made of a combination of magnesium, silicon, or silicon with a magnesium additive; are water-soluble; and disappear after a few hours.
One of the obstacles to creating a final working product is the need for a coating that can protect the circuits. When external fluids reach the inside of the packaging, the circuits will begin to degrade. The job for which the circuit is designed must be complete before that step occurs. SINTEF researchers gave as an example a circuit package designed to be used in seawater and fitted with sensors for measuring oil spills. The film must be made so that it remains in place for the weeks during which the measurements are being taken.
“It's important to make it clear that we're not manufacturing a final product, but a demo that can show that an electronic component can be made with properties that make it degradable,” says Karsten Husby, a research scientist in SINTEF's Information and Communication Technology (ICT) division. “Our project is now in its second year, but we'll need a partner active in the industry and more funding in the years ahead if we're to meet our objectives. There's no doubt that eco-friendly electronics is a field which will come into its own, also here in Norway. And we've made it our mission to reach our goals.”
Researchers in the United States have been working on biocompatible electronic devices that can be implanted in the body for various uses — pain management, for example, or to combat infection — and then dissolve over time.
“We make no secret of the fact that we are putting our faith in the research results coming out of the USA,” Husby adds. “The Americans have made amazing contributions both in relation to medical applications, and towards resolving the issue of waste. We are far from this, but we want to try to find alternative approaches to the same problem.”
Along similar lines, other researchers have created what they call the world's first “biological” drone built with biodegradable material that, should the drone crash, will start breaking down upon impact, leaving no evidence of its existence. A team of 15 Stanford University, Brown University, and Spelman College students developed the drone in collaboration with New York-based biomaterials company Ecovative Design for the iGEM (International Genetically Engineered Machine competition) 2014 Giant Jamboree, held Oct 30 to Nov 3 in Boston.
An unmanned aerial vehicle made entirely of biological materials would be able to fly in sensitive areas, for numerous purposes, and leave no trace of its existence in the event of a crash. “No one would know if you'd spilled some sugar water or if there'd been an airplane there,” Lynn Rothschild, lead scientist at NASA's Ames Research Center and an adviser for the student team that created the drone, told New Scientist.
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