John Iwaszko has made many experimental antigravity devices.
Some of these go back to the 1980s. He has several videos on
youtube. These were made on 8mm film and converted over the
years to the computer file formats used today. The quality is OK
considering this. The machines and the knowledge is quite superb.
All his videos are accessible from the link above.

There is also    John Iwaszko's "Anti-gravity" Periodic Table  at the
bottom of his page. A spreadsheet layout of various systems, with
unfilled areas where other concepts may fit. Extremely clever stuff.

Also there is a diagram of interest showing the possible shape
of the field around atoms exposed to electrostatic charge in "lifters".