Samarendra Mohanty has spent the past decade looking for ways to better hold and rotate microscopic objects. It seems the existing techniques are just too big a pain, requiring objects to be visible under a microscope in order to hold or rotate them. That was fine, but was little help to, say, a surgeon or researcher trying to work with a cancer cell inside the human body.
Using a single strand optical fiber, Mohanty was able to develop tweezers that use light to hold a cell in place. It was a useful step, but one that had its limits, since it could only move a microscopic object along a single axis, so Mohanty began brainstorming how it could be improved.
The idea he settled on was simple, at least in theory. A second optical fiber could be positioned opposite the first. The twin beams of light, striking an object from opposite sides, could cause it to rotate or move in whatever direction a researcher desired. The trick was to accomplish that task without having the object slip, which Mohanty and graduate student Bryan Black were able to do, with smooth muscle cells, red blood cells, and tiny particles of styrofoam.
They dubbed it the fiber-optic spanner (the British term for wrench), and published their findings in the most recent issue of the academic journal Optics Letters.
While it will take a lot more research and a lot more money before it's ready for the clinic, Mohanty thinks it will be a boon to biomedical research, allowing researchers to better determine whether cells are normal or cancerous, unravel individual strands of DNA and perform in vitro fertilization more precisely, among other potential uses.
More intriguing is that Mohanty thinks the technology can be applied to space travel.
"I envision applications in the direct conversion of solar energy to mechanical energy, rotating large, macroscopic objects using this technique," Mohanty told ScienceBlog. This would "simulate an environment in which photons radiated from the Sun could propel the reflective motors in solar sails, a promising future technology for deep-space travel."
In an email to Unfair Park, Mohanty elaborated.
"Solar sailing is a way by which sun light can push large mirrors (just like wind) and thus move the space ship carrying the mirrors," he wrote. "I also think rotational torque exerted by sun light can rotate mirror arms on a wheel to propel, guide and navigate the ship. (The) fiber optic spanner can simulate such condition in lab so as to efficiently design the ship, mirrors etc."
