Dr Who's sonic screwdriver 'invented' at Dundee University
Scientists claim to have invented their own version of Doctor Who's famous sonic screwdriver.
The Dundee University researchers have created a machine which uses ultrasound to lift and rotate a rubber disc floating in a cylinder of water.
It is said to be the first time ultrasound waves have been used to turn objects rather than simply push them.
The study could help make surgery using ultrasound techniques more precise, the physicists said.
Surgeons use ultrasound to treat a range of conditions without having to cut open a patient.
The ability to steer ultrasound waves to the precise spot where they are needed could make those treatments even more effective.
The ultrasound waves could also be used to guide a drug capsule through the body and activate it, for instance right inside a tumour.
Ultrasound waves could already be made to push objects and scientists believed they could also turn them - but the Dundee University team claims to have now proved it.
They used energy from an ultrasound array to form a beam that can both carry momentum to push away an object in its path and, by using a beam shaped like a helix or vortex, cause the object to rotate.
Dr Mike MacDonald, of the Institute for Medical Science and Technology (IMSAT) at Dundee, said: "This experiment not only confirms a fundamental physics theory but also demonstrates a new level of control over ultrasound beams which can also be applied to non-invasive ultrasound surgery, targeted drug delivery and ultrasonic manipulation of cells.
"The sonic screwdriver device is also part of the EU-funded nanoporation project where we are already starting to push the boundaries of what ultrasound can do in terms of targeted drug delivery and targeted cellular surgery.
"It is an area that has great potential for developing new surgical techniques, among other applications, something which Dundee is very much at the forefront of.
"Like Doctor Who's own device, our sonic screwdriver is capable of much more than just spinning things around."
The results of the sonic screwdriver experiment will be published in the American Physical Society's journal Physical Review Letters.
The research also forms part of a UK-wide Engineering and Physical Sciences Research Council project known as Sonotweezers, which aims to bring dexterity and flexibility to ultrasonic manipulation, allowing applications in a wide range of topics including regenerative medicine, tissue engineering, developmental biology and physics.
In the popular BBC TV series, Doctor Who uses his sonic screwdriver to perform medical scans, remotely control other devices and pick locks.