• Taking in oxygen: mammals - lungs; fish - gills

• Long-held dreams - humans swimming underwater without oxygen tanks

• Oxygen tanks considered too  and large

• Attempts to extract oxygen directly from water

• 1960s - prediction that humans would have gills added by 

• Ideas for artificial gills were inspired by research on

  • fish gills

  • fish swim bladders

  • animals without gills - especially bubbles used by 

Building a simple artificial gill

• Make a watertight box of a materiaI which lets  pass through

• Fill with air and submerge in water Important that the diver and the water keep

• The gill has to have a large

• Designers often use a network of small  on their gill

• Main limitation - problems caused by increased   in deeper water

Other applications

• Supplying oxygen for use on 

• Powering   cells for driving machinery underwater