Getting microscopic objects into formation is a tricky proposition. They don't make tweezers small enough. Fortunately there's an alternative: sweeping them up in a sonic vortex.
In a recent experiement, researchers at the University of Bristol's Department of Mechanical Engineering and the University of Dundee's Institute for Medical Science and Technology managed to catch tiny particles in a sonic lasso and gentle coax them into position a short distance away for the first time. They pulled it off by surrounding the target particle with a ring of 16 ultrasound sources which spat out the swirling vortex, catching the particle inside. And after that it's a just a matter of moving the lasso.
Bruce Drinkwater, Professor of Ultrasonics in the Department of Mechanical Engineering and leader of the study, described it this way:
Our research has shown we can grip and move particles pretty much anywhere and along any path. The impressive thing is that it is completely non-contact, harmless and so ideal for moving delicate things, such as cells, around under a microscope. With further development this could be used to assemble human tissue as part of a tissue engineering production line.
With a 3d-printing future looming on the horizon, the ability to gingerly position delicate microscopic particles without busting them up in the process is bound to come in handy sooner or later. It's just an added bonus that we pull it off by rocking out. [Phys.Org via Geekosystem]