Dutch team builds a soft robot arm powered by algae
Researchers at Delft University of Technology in the Netherlands built a small strip of two hydrogel layers with microalgae growing on it. It bends back and forth as the light changes, and it can grasp and lift small objects. The work is peer-reviewed in Nature Communications.
Professor Marie-Eve Aubin-Tam led the work, and PhD candidate Fan Jiang was first author. In light, the algae make sugars through photosynthesis and raise the pH in the hydrogel. The two layers swell by different amounts, so the strip bends. In the dark the pH falls, and the strip starts to bend the other way within 10 seconds. The strip is about 2 cm long and 1 mm thick. Aubin-Tam calls it a proof-of-concept, and the team had no specific application in mind.