The untethered flght is in the second half of the video. From a paperby Charles Richter and Hod Lipson:
"This project has focused on developing a flapping-wing hovering insect using 3D printed wings and mechanical parts. The use of 3D printing technology has greatly expanded the possibilities for wing design, allowing wing shapes to replicate those of real insects or virtually any other shape. It has also reduced the time of a wing design cycle to approximately one hour. An ornithopter with a mass of 3.89g has been constructed using the 3D printing technique and has demonstrated an 85- second passively stable hovering flight. This flight exhibits the functional utility of printed materials for flapping wing experimentation and ornithopter construction."