Delft University researchers develop algae-powered soft robotic arm

Researchers at Delft University of Technology have developed a soft robotic arm capable of grasping and moving objects using light and microalgae as a power source. The actuator is a green, flexible strip approximately 2 cm long and 1 mm thick, constructed from two different hydrogel layers with microalgae growing on its surface.

The device utilizes the biological processes of the algae, specifically Chlamydomonas reinhardtii. When exposed to light, the algae perform photosynthesis, which alters the pH levels of the surrounding water. By utilizing hydrogel layers that react differently to these pH changes, the strip can perform reversible bending movements.

In demonstrations, the team used the actuator to hook a rubber ring and grasp a small metal ball. The technology is particularly suited for underwater environments where gentle handling is required. Potential future applications include agricultural devices or blinds that change shape in response to light conditions.