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Chapter 19 Nanotechnology. Chemistry in Focus 3rd edition Tro. Out of SciFi; Into the Lab. Five atoms, end to end, measure a nanometer (10 -9 m). Human hair measures 20,000 nm in diameter. Can we make a machine so tiny is could navigate the bloodstream? Nature has already done this.
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Chapter 19 Nanotechnology Chemistry in Focus 3rd editionTro
Out of SciFi; Into the Lab • Five atoms, end to end, measure a nanometer (10-9 m). • Human hair measures 20,000 nm in diameter. • Can we make a machine so tiny is could navigate the bloodstream? • Nature has already done this. • Some see nanotechnology as bioimitation.
Scanning Tunneling Microscope • 1981 Binnig and Rohrer measuring electrical conductivity over a surface • Noticed bumps in their measurements which have been interpreted as individual atoms • Modern STMs scan surfaces of interest with atomically fine metallic tips. • We can not only image atoms, but move them
Atomic Visibility • STM made the atomic world visible for the first time. • Premier tool for scientists developing nanotechnology • Binnig and Rohrer were awarded the 1986 Nobel Prize in physics for this work.
Atomic Force Microscope • STM can image only metallic surfaces • AFM (atomic force microscopy) can image nonmetallic surfaces • AFM tracks the movement of a laser reflected off the back of a cantilever • Tapping AFM can image biological samples
Buckyballs • Graphite – carbon atoms in layered sheets • Diamond – three-dimensional honeycomb • Buckyballs – 60 carbon atoms bonded into a hollow sphere • Smalley, Curl, Kroto awarded the 1996 Nobel Prize in chemistry • Named for R. Buckminster Fuller, American architect of geodesic designs resembling C60
Nanotubes • 1991 marks the birth of the buckytube • Shape is tubular instead of spherical • A few atoms in diameter but kilometers in length • Strong as steel • Can be made electrically conducting
Conducting Electricity with Nanotubes • Tiny electric circuits may allow • Flat-panel displays • Water desalination • Flexible, foldable monitor displays
Nanomedicine • Doctors can encase foreign cells so that the body will not reject them. • Pancreatic animal cells can be introduced into a human diabetic patient.
Artificial Cells and Nanorobots • Can we construct nanomachines that mimic living cells? • Can we construct nanorobots that can do work within biological systems? • Current work involves targeted drug delivery • Protection of healthy cells from chemo drugs • Concentrated delivery of toxins to cancerous tissue
Nanoproblems • Can nanotechnology visionaries go to far? • How will the ethics of such power be handled?