Science Daily brings us one step closer to a sci-fi tomorrow with researchers publishing open-source directions on making a tractor beam at home:
Last year Asier Marzo, then a doctoral student at the Public University of Navarre, helped develop the first single-sided acoustic tractor beam — that is, the first realization of trapping and pulling an object using sound waves from only one direction. Now a research assistant at the University of Bristol, Marzo has lead a team that adapted the technology to be, for all intents and purposes, 3-D printable by anyone (with some assembly required, of course).
Sonic levitation is not new, and the use of sound waves to push around macroscopic objects, or create patterns in resting sand and flowing water, is scattered throughout YouTube and has been for years. This technology, however, is not simply sonic levitation, using sound to push objects around.
Based on similar fundamental physics used to create optical traps for decades, these tractor beams are true to their name in that they pull objects, trapping small beads — and even insects — at their foci.
“The most important thing is that it can attract the particle towards the source,” said Marzo. “It’s very easy to push particles from the source, but what’s hard is to pull them toward the source; to attract the particles. When you move the tractor beam, the particle moves, but otherwise the trap is static. It can levitate small plastics; it can also levitate a fly and small biological samples. It’s quite handy.”
Besides seriously impressing dinner guests, these DIY tractor beams have many potential uses and may even become a new tool for studying low-gravity effects on biological samples. Marzo pointed out this type of “micro-gravity” research is already of interest and encouraged biologists to find their own applications for the device.
“Recently there have been several papers about what happens if we levitate an embryo, how does it develop? Or what happens if we levitate bacteria?” he said. “For instance, they discovered salmonella is three times more [virulent] when it’s levitated. Certain microorganisms react differently to microgravity.”
There are three designs of the device, each with trapping profiles suitable for different object sizes relative to the wavelength of sound used.