Scientists Think They've Figured Out How to Build a Real-Life Tractor Beam
A tractor beam—a special beam of electromagnetic radiation that draws particles toward it instead of pushing them away—might be a concept straight from Star Trek, but scientists from the Australian Research Council’s Centre of Excellence for Transformative Meta-Optical Systems (TMOS) have recently taken steps toward a more portable way to generate one in real life.
The Melbourne-based research team says that this could lead to better, less invasive technology that could perform a biopsy without the cell trauma caused even by the smallest handheld tweezers or needles. The team’s paper appears now in the peer-reviewed journal ACS Photonics (from the American Chemical Society).
While “tractor beam” makes us think of science fiction and intergalactic tow trucks, the most realistic application of a near-future tractor beam is in healthcare. Today, people who need biopsies are subjected to, at the very least, a needle wide enough to take a sample of cells. Often, the procedures are more involved (like those that involve handheld forceps) and leave more tissue damage in their wake. These procedures are very safe and essential, but medical care with less or no cutting is almost always safer and less painful than what came before.
The secret of this new tech is the triple helix solenoid beam—a twist of three “strands” of light that form an overall tunnel or tube shape. They’re generated by passing a normal beam of light (also known as a Gaussian beam) through a specially created metasurface, which itself functions like a pasta extruder or light stencil. The metasurface is made of whisper-thin nanopatterned silicon on a panel of glass. Metasurfaces, in general, use micro-etched or prepared surfaces to change the form of electromagnetic waves. Different types have different outcomes, like a variety pack of pasta-shaping plates.
