Tractor beam powers up at ANU

Members of the scientific team: Yana Izdebskaya, Anton Desyatnikov, Vladlen Shvedov, Andrei Rode, Yuri Kivshar and Wieslaw Krolikowski. Photo: Tim Wetherell

Science fiction has become fact at The Australian National University with researchers building a working tractor beam.

Dr Andrei Rode and his team from the Laser Physics Centre at ANU have developed a beam that can move very small particles up to distances of a metre and a half using only the power of light.

Dr Andrei said that the technology uses a hollow laser beam to trap light-absorbing particles in a ‘dark core’ to move them up and down the beam of light which acts like a ’pipeline’.

‘When the small particles are trapped in this dark core very interesting things start to happen,’ said Dr Rode.

?As gravity, air currents and random motions of air molecules around the particle push it out of centre, one side becomes illuminated by the laser whilst the other lies in darkness.

?This creates a tiny thrust, known as a photophoretic force that effectively pushes the particle back into the darkened core.

‘In addition to the trapping effect, a portion of the energy from the beam and the resulting photophoretic force pushes the particle along the hollow laser pipe.’

Whilst the tractor beam won?t work in the vacuum of space, the breakthrough by Dr Rode and his team has many important uses back down on Earth.

‘There are a number of practical applications for this technology,’ said Dr Rode.

‘These include the micro manipulation of objects, sampling of atmospheric aerosols, and low contamination, non-touch handling of sampling materials.’

Read a full article about Dr Rode and the research team’s tractor beam in the Spring edition of ScienceWise, available online from Thursday 23 September 2010.