"Once it's fully loaded, then the order is ready. And another one comes with the order in a cup in the grip."
The cafe is offering four different alcoholic and non-alcoholic cocktails, which are either bright blue or green -- the same color as the drone's "eyes."
The drinks are picked up and carried by a set of pinchers underneath the drone, in a bid to show that these aerial machines could be used to carry out delicate missions such as delivering medicines or even helping to track down burglars.
Each drone has cost about 2,000 euros to build, in a project funded by the university which the students say aims "to give a glimpse of the future."
Thanks to sensors and a long battery life they can fly inside buildings and navigate crowded interiors, unlike other drones, which rely on a GPS system.
"The Blue Jay is an intelligent bird that lives in complex, social environments," the students say in a video presenting their work.
They believe the drone's applications could be endless: as extinguishers to put out fires, alarm systems to warn of intruders or mini-servants which would respond to commands such as "fetch me an apple."