The nature-inspired drone

It switches environments seamlessly.

Scientists from MIT and EPFL have developed a small robot—weighing approximately 250 grams—capable of flying, submerging, swimming, and then taking off again using the same set of wings. The machine aims to solve one of the toughest challenges in robotics: building a single propulsion system capable of operating in two completely different environments.

The problem lies in physics.

Water is approximately 800 times denser than air; a wing that is efficient for flight can be subjected to enormous forces when submerged, whereas a structure designed for swimming is typically too heavy to take off. Instead of creating two independent systems, researchers developed flexible wings capable of passively adapting to the environment.

In the air, they flap at high frequency to generate lift; underwater, the fluid's resistance causes the wings to deform, reducing drag and the load on the motors. The drone was also designed to operate near neutral buoyancy, avoiding the constant energy expenditure required to rise or sink, but the greatest challenge arises at the boundary between the two worlds. To exit the water, the robot must tilt its body to the correct angle and execute a rapid sequence of wingbeats capable of breaking the surface tension.

In less than a second, it leaves the water and takes flight again. Built using relatively accessible components and 3D-printed parts, the project could also pave the way for low-cost drones capable of monitoring rivers, oceans, and coastal regions. By emulating solutions perfected by evolution over millennia, robotics is beginning to create machines that do not need to choose between the sky and the ocean; they will be able to master both.