The role of multi rotor UAV is becoming more and more important, but its exposed rotating propeller may be damaged in collision and cause damage to bystanders. A new prototype drone solves this problem, mimicking the puffer fish. When it feels threatened by other animals getting too close, puffer puffers inflate their air like balloons, making them bigger. The puffer BOT, designed by a team of engineers at the University of Colorado at Boulder, takes a similar approach. < / P > < p > in normal flight, an array of linked, pre tensioned plastic rods is folded up against the fuselage of the quad. But when the UAV’s proximity sensors detect that someone (or something else) is too close, the poles push outward. This causes the array to expand into a shield around the drone’s fuselage. The shield consists of a horizontal ring that runs through the propeller and two intersecting vertical arches to the top. < / P > < p > therefore, the pufferbot is likely to just bounce away from people or other obstacles, rather than cut in or be damaged by them. In addition, the shield deployment can also serve as a visual warning, which may allow bystanders to avoid collision with the UAV in the first place. < / P > < p > the study, led by graduate student Hooman hedayati, will be presented later this month at the Online International Conference on intelligent robots and systems (iros 2020). Global Tech