Voyager penetrating the Taresian 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. (VOY: "Favorite Son")
Chakotay also referred to the polaron grid as a tachyon grid.
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. (VOY: "Equinox")