Kirigami Films Enable Low-Power Solar Sail Control with Tunable Buckling
Scientists have developed a new way to steer solar sails in space using kirigami-structured films. The technology, created by researchers at the University of Pennsylvania, replaces traditional propulsion with lightweight, foldable reflectors that redirect sunlight for controlled movement.
The team used an aluminised polyimide film, cutting it into kirigami patterns to form flexible reflectors. When stretched, the film buckles and redirects incoming light at an angle, producing a sideways force. This allows the sail to change direction without fuel or heavy mechanical parts.
Computer simulations predicted how the film would bend and reflect light. Physical tests later confirmed these models, showing beam patterns that matched the calculations. The approach builds on earlier work, such as the 2011 vortex-phase-plate structure by Federico Capasso and colleagues at Harvard, which shaped light beams to create controllable forces. Kirigami designs let the reflectors fold compactly for launch and expand into large, stable surfaces in orbit. By combining these patterns with metasurfaces, the team broke the limits of conventional reflection laws. The result is a system that steers solar sails by adjusting the angle of reflected sunlight, offering precise control with minimal energy. The research highlights potential uses beyond solar sailing. These include space-based antennas for communications and orbital solar power stations that concentrate sunlight for energy generation.
The kirigami-based films provide a lightweight, fuel-free alternative for steering spacecraft. Their ability to fold for launch and expand in space makes them practical for future missions. The technology could also improve satellite communications and power systems in orbit.
