Polaron grid

A polaron grid was a powerful energy field which could be used to great effect in protecting a device, or even an entire planet, from outside incursion.

The inhabitants of Taresia, a planet in the Delta Quadrant, utilized a high-density polaron grid to prevent ships from entering orbit to rescue individuals which they had kidnapped for the purpose of collecting genetic material. Such a grid was utilized in 2373 in order to prevent the crew of the USS Voyager from retrieving Ensign Harry Kim. Commander Chakotay and Lieutenant Tuvok were able, however, to devise a new shield configuration, which allowed Voyager to force its way through the grid and beam Harry aboard. 

The multiphasic chamber constructed by the crew of the USS Equinox in 2376 contained a polaron grid and a submolecular resequencer, for use in converting the remains of nucleogenic lifeforms into a source of power with which to augment their warp engines.