Tiny underwater algae sway gently in the current. All of a sudden, a light shines on them and they form robotlike arms that start to pick up small rocks and put them in floating baskets. Sounds like science fiction, but researchers from Delft University of Technology (the Netherlands) have created a small soft robot arm covered with minuscule algae that can grasp and lift objects. And it's powered by light. This next step in biotechnology has been published in Nature Communications.