Researchers at the Max Planck Institute for Intelligent Systems have created microscopic machines that can slowly swim through non-Newtonian fluids, such as those found in connective, epithelial and neural tissues.
Made out of silicon rubber, the robots are cast in a 3D printed mold. Just like a scallop, each robot has two shells connected by a thin, narrow hinge. But these shells have a rare earth micro magnets attached — one per shell. When the magnets are exposed to an external magnetic field the shells close. When the magnetic field is decreased, the shells open. While the robot moves on both strokes — back and forth — the net movement through a non-Newtonian fluid is forward.
While the current approach uses magnets make the micro scallops move, the researchers say the same reciprocal motion could be generated including a variety of other materials, including memory alloys, bimetal stripes, or light-actuated polymers. According the journal article published by Nature, the successful swimming technique is the first step toward creating robots that can swim in the human body for biomedical applications.