A borg drone holds a plasma charge
The plasma charge is an explosive device used by Starfleet which utilizes the high-energy state of matter known as plasma.
In 2372, Miles O'Brien used a plasma charge to escape from Meso'Clan. (DS9: "Hippocratic Oath")
In 2376, Ensign Harry Kim unsuccessfully attempted to disable the shield generator of a Borg cube manned by neo-natal drones using plasma charges. (VOY: "Collective")