Soft robotic arm moves using living algae
A soft robotic arm covered in algae, housed inside a specially constructed aquarium. (Photo: Studio Oostrum/TUDelft)
October 22, 2026 – Researchers at Delft University of Technology have developed a soft robotic arm powered by living microalgae. The miniature robot can grasp and lift objects in response to changes in light.
The robotic arm consists of a flexible strip approximately 2 centimetres long and 1 millimetre thick. It contains two layers of hydrogel, a water-rich material, with microalgae growing on its surface.
When exposed to light, the algae produce sugars through photosynthesis. This changes the acidity of the hydrogel. Because the two layers respond differently, the strip bends.
In darkness, the acidity changes again, causing the arm to move back. Within ten seconds, it begins bending in the opposite direction.
During experiments, the robotic arm lifted a rubber ring and grasped a small metal ball.
Researchers believe the technology could contribute to energy-efficient soft robots that respond to their surroundings, particularly for delicate tasks underwater.
A soft robotic arm covered in algae, housed inside a specially constructed aquarium. (Photo: Studio Oostrum/TUDelft)
The results of the study were published on October 22 in Nature Communications under the title ‘Light-powered photosynthetic living actuator’.
