From that article: > Greg reasoned that if he could reduce or even eliminate these tip vortices, it should lead to a quieter, more efficient drone. His light b

From that article: > Greg reasoned that if he could reduce or even eliminate these tip vortices, it should lead to a quieter, more efficient drone. His light bulb moment came on a dog walk when the idea of a tipless blade, that loops round to rejoin the propeller hub like a strip of twisted ribbon, first popped into his head. > It took a further seven years of intensive research and development, substantial investment, 23 worldwide patents and a switch in focus from drones to boats before Sharrow Engineering unveiled its first production propeller It seems that Sharrow was initially trying to tackle drones, but found boat props to be a lower-hanging fruit. This all makes me wonder who has priority on the patent -- MIT, or Sharrow?