Video of the week: How to build your own tractor beam

Tractor beams seize and attract objects and scientists have been developing the theory using lasers. Sound has been used to create a working tractor beam that can move heavier objects made of different materials and operates in air or water without damaging the trapped objects.

In a paper published in Applied Physics Letters (APL), researchers from Bristol’s Department of Mechanical Engineering have shown that it is possible to build a simplified tractor beam using only one electrical signal and a passive wave modulator, which is a type of acoustic lens that can alter the transmitted or reflected waves.

According to the University, the passive wave modulator can be made in various different ways. In one example it’s a collection of tubes of differing lengths, and in another it’s a carefully contoured surface. In both cases, it can be 3D printed using an off–the-shelf printer. Using a single waveform a static tractor beam can be created. If two waveforms are used then up and down manipulation of objects can be achieved.