A tunneling neutrino beam was a type of beam composed of neutrinos that could be used to penetrate other materials. One possible use was to remove a rare subatomic bacteria from the hull of a starship. Such a use was devised by Mendon on board the USS Enterprise-D in 2365 to remove such a bacteria from both that ship and the Klingon vessel IKS Pagh. (TNG: "A Matter Of Honor")