Interesting that the Boeing site makes no mention of the original Whitcomb/NASA research many many moons before the Boeing testing
Research on wingtip devices goes back further .. when I was a student in the late 60s, E.D. Poppleton, at Sydney University, was active in investigating quite strange configurations as precursors to the simpler sails which ended up in the marketplace. At one stage I was looking at doing my undergrad thesis on such a device modelled on an F27 ... practical handling considerations in crosswinds would have made it impracticable as conceived .. but the thought was interesting ..