University Of Minnesota Researchers Move Objects Hands-free With Ultrasound Waves

University of Minnesota researchers have discovered a new method to move objects using ultrasound waves. The research opens the door for using contactless manipulation in industries such as manufacturing and robotics, where devices wouldn’t need a built-in power source in order to move.

While it’s been demonstrated before that light and sound waves can manipulate objects, the objects have always been smaller than the wavelength of sound or light, or on the order of millimeters to nanometers, respectively. The research team has developed a method that can move larger objects using the principles of metamaterial physics.

Metamaterials are materials that are artificially engineered to interact with waves, like light and sound. By placing a metamaterial pattern on the surface of an object, the researchers were able to use sound to steer it in a certain direction without physically touching it.

“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,’” said Ognjen Ilic, senior author of the study and a professor in the College of Science and Engineering.

Using this technique, the researchers can not only move an object forward but also pull it toward a source — not dissimilar from the tractor-beam technology in science fiction stories like Star Trek.

“Contactless manipulation is a hot area of research in optics and electromagnetism, but this research proposes another method for contactless actuation that offers advantages that other methods may not have,” said Matthew Stein, first author on the paper and a graduate student in the College of Science and Engineering.

While this study is more a demonstration of the concept, the researchers aim to test out higher frequencies of waves and different materials and object sizes in the future.

“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. “This gives us a new mechanism to contactlessly operate things.”