Researchers in Germany have developed a new drone interceptor that uses thin metal chains to disable unmanned aerial vehicles (UAVs) midair by tangling their spinning rotors.

The concept was made by scientists at the Karlsruhe Institute of Technology (KIT). It adapts the physics behind the traditional South American bola weapon into a modern drone defense technology designed for short-range interception.

The system works by firing lightweight, thin metal chains towards incoming UAVs. Once the chains make contact, they reportedly wrap around the drone body and rotors. This way, they prevent the propellers from spinning and force the aircraft into a controlled crash.

“We use a well-known physical principle similar to the bola used by shepherds in South America and adapt it specifically for drone defense,” Claus Mattheck, PhD, a distinguished senior fellow at KIT’s Institute for Applied Materials, who created the method together with external partners, pointed out.

An anti-drone chain system

Drones have recently become an increasing concern in both military and civilian environments. They pose a particular threat to airports, industrial facilities, and critical infrastructure.

Meanwhile, Germany has recorded repeated sightings of drones near sensitive locations in recent years. In 2025 alone, the country reported more than 1,000 suspicious drone incidents, according to the Federal Criminal Police Office (BKA).

To address the issue, the KIT researchers built a low-cost interception system that could be deployed without sophisticated electronics or even explosive projectiles. “Instead of balls attached to ropes, we use thin chains, which proved superior in simulation calculations,” Mattheck explained.

As the chains strike the drone, they rapidly coil around the aircraft structure and spinning rotor blades. Once entangled, the propellers lose mobility, causing the UAV to fall from the sky.

“Upon contact, the chains wrap around the drone’s body and rotors,” Mattheck continued. “As a result, the rotors lose mobility and the drone crashes.”

The team believes that the approach could offer a simpler and potentially safer alternative to conventional anti-drone systems. They said that existing counter-drone technologies often cost too much, rely on complex systems, and even face deployment limitations.

Simulations and live tests

To evaluate the drone interceptor, the engineers carried out computer simulations and analyzed how metal chains between three and four millimeters thick behaved when colliding with model drones.

Their calculations analyzed factors including geometry, friction, as well as motion dynamics to find out how effectively the chains could wrap around drone rotors during flight. “We verified the fundamental suitability of the method through these computer simulations,” Mattheck said.

“One particular advantage of chains as projectiles is that, when falling, they pose less risk of collateral damage than a compact projectile of the same mass,” he concluded in a press release. “Further verification was carried out experimentally through firing tests at the Ballistics Center in Sternenfels.”

The researchers now aim to expand field testing to evaluate the interceptor under a wider range of operational conditions. If future trials prove successful, the team believes industry partners could move the concept toward practical deployment.

The results of the simulations and initial tests have been published in Aerospace & Defence and Konstruktionspraxis.