Researchers from the University of Minnesota have developed a technique for moving objects without any physical contact, instead using just ultrasound waves and metamaterials. This new technique could have important implications for robotics, manufacturing, and other fields. The study is published in Nature Communications.
Key to understanding this new research is understanding metamaterials, which are “artificially structured materials used to control and manipulate light, sounds, and many other physical phenomena,” according to Duke University. In other words, metamaterials are used to assign physical properties to objects that do not naturally have those properties. The research team covered the surfaces of small objects with metamaterials, creating a “metasurface” that allows the object to be influenced by forces of nature—in this case, ultrasonic waves. Senior study author and professor Ognjen Ilic said, “We have known for a while that waves and light and sound can manipulate objects. What sets our research apart is that we can manipulate and trap much bigger objects if we make their surface a metamaterial surface, or a ‘metasurface.'"
Much like UFO tractor beams depicted in science fiction media, this contactless manipulation technique can push objects away, pull them closer, and steer them in specific directions. A video of the technique in action shows a wall of ultrasonic speakers pointed at a small, rectangular bar covered in metamaterial. Three seconds into the video, the speakers activate and begin pushing the metasurfaced object away and to the right, sliding it across the workbench with no physical contact.
The researchers hope to refine this technique by testing it with different materials and larger objects. “I think we’re charting in a new direction here and showing that without physical contact, we can move objects, and that motion can be controlled simply by programming what is on the surface of that object,” Ilic said.