Scientists created acoustic holograms with shapes such as tweezers, twisters and cages that exert forces on particles to levitate and manipulate them. (Credit: Asier Marzo, Bruce Drinkwater and Sriram Subramanian) It’s a classic science fiction scene: A large vessel moves near a smaller one, captures it in a so-called tractor beam, and pulls it inside. Now imagine bringing that technology to life, but instead of moving meddlesome space ships, terrestrial tractor beams would perform touchless assembly, microsurgery or deliver drugs directly to the body part that needs them. You may not have to imagine for long: A British research team is making early strides toward developing small-scale tractor beams, using high-amplitude sound waves to create invisible force fields they can adjust in real-time.