Soundwaves used to levitate objects to improve surgery

Posted Jan 6, 2019 by Tim Sandle
Researchers have successfully used soundwaves to levitate multiple objects, paving the way for the technology to be used for techniques like surgery, enabling medics to undertake procedures without having to touch parts of the patient directly.
A surgeon in the rebel-held Syrian town of Douma holds his phone up during an operation to receive r...
A surgeon in the rebel-held Syrian town of Douma holds his phone up during an operation to receive real-time guidance from a colleage over the internet on October 11, 2017
Hamza Al-Ajweh, AFP
Sound can levitate objects of different sizes and materials through air, water and tissue. The futuristic technology to assist with medical procedures has been developed by scientists working at the University of Bristol. The idea builds on earlier developments with optical tweezers. A limitation with optical tweezers is that the lasers used with the technology do not penetrate biological tissue very well; there is also a risk that the lasers can damage living cells. This can be overcome through the use of sound waves.
The technology takes the form of an array of mini-speakers (two sets of 256 speakers) that can be tuned, via a computer system, so they create an intricate sound field. These soundwaves serve to 'trap' and manipulate selected objects within 'acoustic tweezers'.
In medicine, this process could be used for carrying out precise manipulations within tissue. Other related applications could include the assembly of 3D microstructures and the probing of soft matter.
By using an array of sound emitters, the scientists succeeded in engineering a generated sound field in order to manipulate multiple particles individually.
To test out the system, the researchers manipulated Styrofoam balls ranging in size from one to three millimeters in diameter. The video below shows the prototype in action:
According to lead researcher Professor Drinkwater further developments of the system could see surgeons acoustically stitching up internal injuries or even delivering medicines to target organs.
Drinkwater notes: "Now we have more versatility -- multiple pairs of hands to move things and perform complex procedures, it opens up possibilities that just weren't there before."
The research has been published in the Proceedings of the National Academy of Sciences. The research paper is succinctly titled “Holographic acoustic tweezers.” The research was funded by the UK Engineering and Physical Science Research Council (EPSRC).