An ultrasonic device for micro-patterning and precision manipulation of micrometre-scale particles is demonstrated. The device is formed using eight piezoelectric transducers shaped into an octagonal cavity. By exciting combinations of transducers simultaneously, with a controlled phase delay between them, different acoustic landscapes can be created, patterning micro-particles into lines, squares, and more complex shapes. When operated with all eight transducers the device can, with appropriate phase control, manipulate the two dimensional acoustic pressure gradient; it thus has the ability to position and translate a single tweezing zone to different locations on a surface in a precise and programmable manner.
Bernassau, A. L., Courtney, C. R. P., Beeley, J., Drinkwater, B. W., & Cumming, D. R. S. (2013). Interactive manipulation of microparticles in an octagonal sonotweezer. Applied Physics Letters, 102(16), . https://doi.org/10.1063/1.4802754