The three-dimensional shells of tiny ocean creatures could provide the foundation for novel electronic devices, including gas sensors able to detect pollution faster and more efficiently than conventional devices.
Using a chemical process that converts the shells original silica (silicon dioxide, SiO2) into the semiconductor material silicon, researchers have created a new class of gas sensors based on the unique and intricate three-dimensional (3-D) shells produced by microscopic creatures known as diatoms. The converted shells, which retain the 3-D shape and nanoscale detail of the originals, could also be useful as battery electrodes, chemical purifiers and in other applications requiring complex shapes that nature can produce better than humans.
"When we conducted measurements for the detection of nitric oxide, a common pollutant, our single diatom-derived silicon sensor possessed a combination of speed, sensitivity, and low voltage operation that exceeded conventional sensors," said Kenneth H. Sandhage, a professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. "The unique diatom-derived shape, high surface area and nanoporous, nanocrystalline silicon material all contributed towards such attractive gas sensing characteristics."
The unique devices, part of a broader long-term research program by Sandhage and his research team, were described in the March 8 issue of the journal Nature. The research was sponsored by the U.S. Air Force Office of Scientific Research and the U.S. Office of Naval Research.
Scientists estimate that roughly 100,000 species of diatoms exist in nature, and each forms a microshell with a unique and often complex 3-D shape that includes cylinders, wheels, fans, donuts, circles and stars. Sandhage and his research team have worked for several years to take advantage of those complex shapes by converting the original silica into materi
Contact: John Toon
Georgia Institute of Technology Research News