He patented the first electric stroboscope in 1917,[1] building at the same time a camera capable of shooting 1,000 frames per second.

On 11 November 1922, he first flew 'Oehmichen No.2', an improved helicopter featuring small vertically mounted rotors which rotated in the opposite direction from the large lifting rotors, probably creating the first reliable flying helicopter capable of carrying a person.

On 4 May 1924, he won a prize of 90,000 French Francs[4] for the first successful closed circuit helicopter flight following a triangular trajectory with a length of approximately one km, a flight which took approximately 7 minutes and 40 seconds.

[5] In 1931, Œhmichen invented and tested a type of blimp he called the "Hélicostat", controlled by four movable propellers, which could hover, take off, and land without ground crew.

He worked at the Collège de France in Paris for 30 years until his retirement.