Phys.org August 18, 2021
Despite all its potential, the acoustic tweezer technology makes it difficult to manipulate particles independently of one another or through complex patterns. To overcome the limitation of the acoustic tweezer a team of researchers in the US (Duke University, Rowan University) has demonstrated spatially complex particle trapping and manipulation inside a boundary-free chamber using a single pair of sources and an engineered structure outside the chamber that they call a shadow waveguide. The shadow waveguide creates a tightly confined, spatially complex acoustic field inside the chamber without requiring any interior structure that would interfere with net flow or transport. Altering the input signals to the two sources creates trapped particle motion along an arbitrary path defined by the shadow waveguide. They experimentally demonstrated particle trapping, particle manipulation and transport. The technology offers a new suite of features to the platform of acoustic tweezers that has applications in fields such as chemical reaction control, micro-robotics, drug delivery, and cell and tissue engineering…read more. Open Access TECHNICAL ARTICLE
Illustration and properties of the microfluidic chamber and shadow waveguide. Credit: Science Advances 18 Aug 2021, Vol. 7, no. 34, eabi5502Â