Fans

Fans have existed for centuries, with the earliest design dating back to the Han Dynasty of Ancient China, an ingenious "seven-wheel fan" —a hand-cranked contraption where seven blades were attached to a single axle. By turning a handle the blades would spin air current created would cool the space. Fast forward to 2009, blade-less fans were introduced. With such a dramatic evolution, what could be the next breakthrough in Fan technology?