Article (science for the public) - nanotechnology development explainer (250 words) This
is one of a series of "explainers" on scientific and technological topics, written for the general public. How small can a motor be? Some biological engineers are pushing nanotechnology’s boundaries by taking advantage of mechanical parts inside bacterial cells. By combining organic and inorganic components, researchers hope to create devices small enough to operate inside individual cells, a feat that cannot be accomplished today using strictly human-made materials. Living cells carry out many mechanical processes, such as transporting energy across membranes or waving bacterial cilia. The particular molecule the engineers raided for parts is called ATPase, an enzyme that converts food into ATP (adenosine triphosphate), energy that a cell can use. The ATPase molecule has a central protein shaft that rotates during the formation or breaking apart of ATP. Could we somehow use this molecule’s machinery? That’s the question Carlo Montemagno, Assistant Professor of Agricultural and Biological Engineering, and his team at Cornell University asked. In order to harness ATPase, they grew modified Escherichia coli bacteria and separated the enzyme molecules from the cell membranes. They then used a synthetic peptide to stick the molecules to a metallic surface, and attached tiny propeller-like filaments to the top of the motor shaft. When the miniscule machine was bathed in an ATP solution, the rotor spun for 40 minutes at three to four revolutions per second. The team considers this experiment a successful platform for producing organic/inorganic hybrid nanoelectromechanical systems (NEMS). “For a technology that wasn’t expected to produce a useful device before the year 2050, I think we’ve make a pretty good start,” said Monetmagno.
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