When a Fruit Fly Loses a Wing, It Doesn’t Crash- And Soon, Drones Might Not Either

A fruit fly with a torn wing doesn't simply fall from the sky. Within milliseconds, it adjusts its flight and keeps going. This remarkable ability has caught the attention of Eric Jurado, a mechanical engineering Ph.D. student and an INSECT NET fellow at Penn State who thinks tiny drones could learn the same trick.

"In robotics, we usually have a direct trade-off between stability and maneuverability, but flies don't seem to have this issue. They use a very advanced control system to benefit from both features” says Eric.

Modern drones are impressive but even with the slightest damage, they would almost certainly crash. Looking at how fruit flies have been able to solve this problem through flapping wing flight, Eric’s goal is to produce a flapping-wing micro-air vehicle (FWMAV) that mimics the behavior of common fruit fly by sustaining flight even when they experience wing damage mid-flight.

For this, Eric has been working to build a physics simulation of an injured fruit fly. Working in Penn State's Bio-Motion Systems Lab with his advisor Jean-Michel Mongeau, he's using an open-source physics engine called MuJoCo to create a virtual fly that behaves like a real one. To verify his simulator’s accuracy, Eric has been comparing the calculated forces against a robotic simulator, which is an actual physical robot that flaps its wings (plexiglass airfoils) in mineral oil. The robot fly is much larger than an actual fruit fly, and the fluid it moves through is far more viscous than air. This is what engineers call a “dynamically scaled model”, which allows Eric to measure something at the macro scale that would be nearly impossible to capture at the micro scale. Moving ahead, Eric wants to incorporate AI to create a sort of “fly brain” that bridges the gap between the forces fly experience and movement it makes to compensate for damage.

Why does this matter? Because flapping-wing flight does just provide maneuverability – it also allows for resilience and robustness. Flapping-wing flight could allow micro-drones to navigate for search-and-rescue operations in unstable environments, monitor the environment under harsh weather conditions, or any scenario where traditional drones would be grounded by the slightest malfunction.

Eric says he has always wanted to create bio-inspired robots and when the opportunity came for him to work as a summer lab technician before his Ph.D., Eric helped build an arena for studying fruit flies in free flight. That experience led him deeper into the question of how these insects manage flight control with such apparent ease. For now, the focus remains on getting the simulation right. The crash-proof micro-drones are still years away, but the foundation is taking shape one virtual wing-flap at a time.

Eric Jurado is a Ph.D. student in Mechanical Engineering program, advised by Dr. Jean-Michel Mongeau. Jurado is a Fellow in Penn State’s INSECT NET program, which is supported by funding from the National Science Foundation’s Research Traineeship Program (Grant 2243979). This article was written by Grace Tiwari, a PhD student in the Entomology program, as a part of the Fall 2025 INSECT NET SciComm Training Workshop.