Scientists how now developed a mini tractor beam that can pull atoms and nanoparticles. Scientists have built a real working tractor beam, albeit at a very small scale. The device, which attracts one object to another from a distance, originates in fiction. The term was coined by E. E. Smith who mentioned the technology in his 1931 novel Spacehounds of IPC, and since the 1990s, researchers have worked to make it a reality.
Tractor beams make intuitive sense. Matter and energy interact with each other in countless ways throughout the Universe. Magnetism and gravity are both natural forces that can draw objects together, so there’s sort of a precedent.
But engineering an actual tractor beam is something different.
Researchers have developed a way to use laser light to pull a macroscopic object. Although microscopic optical tractor beams have been demonstrated before, this is one of the first times that laser pulling has been used on larger objects.
Light contains both energy and momentum that can be used for various types of optical manipulation such as levitation and rotation. Optical tweezers, for example, are commonly used scientific instruments that use laser light to hold and manipulate tiny objects such as atoms or cells. For the last ten years, scientists have been working on a new type of optical manipulation: using laser light to create an optical tractor beam that could pull objects.
Warp drive. Site-to-site transporter technology. A vast network of interstellar wormholes that take us to bountiful alien worlds. Beyond a hefty holiday wish-list, the ideas presented to us in sci-fi franchises like Gene Roddenberry’s “Star Trek” have inspired countless millions to dream of a time when humans have used technology to rise above the everyday limits of nature, and explore the universe.
An acoustic tractor beam that can bend sound around an obstacle to levitate an object on the other side has been created by researchers in the UK. Dubbed SoundBender, the device combines an ultrasound transducer array with an acoustic metamaterial.
In recent years, researchers have used transducer arrays to build sonic tractor beams that can create complex acoustic holograms to manipulate objects in mid-air. Acoustic metamaterials are engineered materials with structural properties that do not usually occur naturally. They have been used to produce acoustic holograms, bend beams of sound and create static acoustic levitation devices. But the team behind the SoundBender, based at the University of Sussex, say that these technologies have key limitations.
Recently, increasing attention has been devoted to mastering a new technique of optical delivery of micro-objects tractor-beam’1, 2, 3, 4, 5, 6, 7, 8, 9. Such beams have uniform intensity profiles along their propagation direction and can exert a negative force that, in contrast to the familiar pushing force associated with radiation pressure, pulls the scatterer toward the light source. It was experimentally observed that under certain circumstances, the pulling force can be significantly enhanced6 if a non-spherical scatterer, for example, a linear chain of optically bound objects10, 11, 12, is optically transported. Here we demonstrate that motion of two optically bound objects in a tractor beam strongly depends on theirs mutual distance and spatial orientation. Such configuration-dependent optical forces add extra flexibility to our ability to control matter with light.