Researchers at the École Polytechnique Fédérale de Lausanne (EPFL), Switzerland, have unveiled a fixed-wing drone that can withstand collisions by mimicking the unique head structure of a woodpecker.
The new aircraft, known as SWIFT, short for Shockproof Woodpecker-Inspired Flying Tensegrity, is designed to survive impacts that would normally destroy similar drones, making way for more robust and dependable aerial robotics.
Fixed-wing drones are widely valued for being faster and more energy-efficient than multi-rotor models. However, their design makes them particularly vulnerable in the event of crashes, as they lack the protective cages that can be fitted to multi-rotor drones.
This weakness has limited their ability to operate safely in cluttered or obstacle-filled environments. The SWIFT project addresses this very challenge by borrowing structural principles from the bird best known for repeatedly hammering its beak against trees without injury.
Woodpecker biology meets drone design
Woodpeckers have evolved in a way that allows them to withstand high-impact pecking without sustaining brain damage.
According to the study, their skull includes a rigid beak, a flexible hyoid bone wrapping around the skull, and a layer of spongy bone between the hyoid and skull bone. Combined with extra free space around the brain, this system redirects impact forces away from sensitive tissues.
With carbon rods, elastic cables, and tensegrity design, SWIFT redefines drone collision. Image: EPFL Via IG/Edisonbilg.
In the SWIFT drone, these biological adaptations are replicated using tensegrity structures, lightweight, self-stabilising frameworks of rigid and flexible elements held together under tension.
Carbon fibre rods stand in for the woodpecker’s beak, while bent carbon fibre strips work in place of the hyoid bone. Elastic cables replace the spongy bone layer, and carbon fibre plates connected with plastic brackets act as the skull.
Instead of protecting a brain, the system shields the drone’s electronic components, motor, and propeller. These are suspended within the fuselage by rubber cables, allowing them to move up to 22 centimetres upon impact. This design absorbs collision energy rather than transferring it directly to fragile components.
Extending resilience to the wings
The drone’s resilience is not confined to its fuselage. In woodpeckers and other birds, the wing joints are reinforced by a network of soft, prestressed connective tissue that helps absorb shocks from collisions with obstacles.
The SWIFT team adapted this idea using 12 elastic cables and carbon fibre rods connecting each wing to the fuselage. This arrangement reduces the risk of wings snapping off on impact and adds an extra layer of protection to the drone’s central components.
Together, the two tensegrity-based systems significantly increase the drone’s durability. Tests have shown that the SWIFT drone can reduce impact forces by up to 70% compared with conventional drones of similar size and weight. The research team validated the concept through controlled indoor crash trials and outdoor flight tests.
Towards safer drones in complex environments
The work, led by researcher Omar Aloui and colleagues, was recently published in Advanced Robotics Research. The study highlights how lessons from biology can inform the engineering of more resilient flying robots.
As drones increasingly operate in cluttered, contact-prone spaces, whether for inspection, mapping, or delivery, improving their ability to withstand collisions could be critical in ensuring safety and reliability.