Science Daily  March 24, 2021 Swimming robots that can “swim” through fluids and carry out useful functions, such as cleaning up the environment, delivering drugs, are often made of brittle polymers or soft hydrogels, which can easily crack or tear. Researchers at UC San Diego made swimmers that were 2 cm long in the shape of a fish that contained a conductive bottom layer; a rigid, hydrophobic middle layer; and an upper strip of aligned, strongly magnetic microparticles. Platinum in the tail, which reacted with hydrogen peroxide fuel to form oxygen bubbles propelled the robot. In a petri dish filled […]