Duru, a software engineer, has devoted the past five years to perfecting his hoverboard design, called Omni. His first attempt was little more than a piece of wood strapped to a motor and propeller. The current iteration—refined by his new company, Omni Hoverboards, and local university students—is made from carbon fiber but still has a DIY feel: It achieves lift with eight large propellers, powered by 16 lithium-polymer batteries.