They’re called “Lifters” and they’re flying (one of many videos) without engines and can hover in place. Now you can build your own (another, step-by-step instruction, here). Lots of people around the globe already have, for a cost of roughly $10 in parts. There are a number of patents surround the technology, some by NASA.

These devices are able to lift their own weight and they are a “modern version” of the Townsend Brown Electrokinetic Apparatus. The Lifters are using the Biefeld-Brown Effect to generate the main thrust to self levitate. A Basic Lifter cell is composed of three Townsend Brown asymmetrical capacitors joined so as to form a triangle assembly.