US Patent 8148001 - Energy storage using nanotube molecules

http://www.freepatentsonline.com/8148001.html

The deformation of elastic springs is one of the oldest forms of energy storage but suffers from a low energy storage density. This patent based on research conducted at M.I.T. teaches a way to use carbon nanotube material for elastic spring energy storage which may improve energy storage density. Claim 1 reads:

1. An energy storage device comprising;

at least one nanotube structure having one nanotube, a multi-molecular assembly of interacting nanotubes, an array of non-interacting nanotubes, or non-interacting assemblies of interacting nanotubes, said at least one nanotube structure being independent of electric charge or current; and

an energy storage, maintenance, and recovery mechanism for converting energy that is external to said energy storage device into potential energy by applying strain on said at least one nanotube structure, maintaining said potential energy of strain for an arbitrary period of time, with no losses due to friction, by fixating said at least one nanotube structure in a non-moving state, and converting said potential energy of strain back into external energy by relaxing said strain on said at least one nanotube structure.