Cell agglomeration using guided surface acoustic waves through a couplant layer

Cell agglomeration has been useful and crucial for tissue engineering, cell culturing, and drug testing, such as for cancer drug development. However, most of the methods require specific and complex experimental setups and the resulting agglomerates are generally slow or of poor quality. We propose a microfluidic device using surface acoustic waves (SAWs), a contact-free means, in the application of cell engineering. It is composed of a piezoelectric substrate, 127.86 deg Y-rotated X-propagating lithium niobate, and a focused interdigital transducer to generate focused surface waves with a resonant frequency at 100 MHz. An aluminum guiding layer is deposited on top of the substrate to overcome the beam steering and lateral diffraction problems due to the anisotropy nature of the piezoelectric material, further trapping the wave to a small region of a few wavelengths. The SAWs generated travel into a thin layer of liquid and diffract at the Rayleigh angle, so that the acoustic radiation is coupled and pro...