Chemistry in Focus 3rd edition Tro Chapter 19 Nanotechnology

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 C 60

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

Weighing and Writing with Atoms

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?