Complex sentence: Dr Bussard's company EMC2 developed the initial devices for the U.S. Navy, during the 19?? s. And although its potential abilities are disputed, research into the polywell continues (as of June 2014) under U.S. Navy funding.
Split into simpler sentences: Dr Bussard's company, EMC2, developed the initial devices for the U.S. Navy. And, although its potential abilities are disputed, research into the polywell continues (as of June 2014) under U.S. Navy funding.