Cell enrichment method based on zinc oxide thin film surface acoustic wave device

To address common issues such as fragility and lack of flexibility at high temperatures in traditional piezoelectric single crystals like LiNbO₃, an approach diverging from conventional cell-enrichment piezoelectric crystals is proposed. This approach involves the fabrication of a zinc oxide (ZnO) film, approximately 3.83 μm thick, on a silicon substrate using magnetron sputtering technology. The performance of the film was characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Furthermore, a 195 MHz interdigital transducer (IDT) was prepared on the film’s surface, exhibiting an insertion loss of −33.8 dB. The acoustic field of the device was simulated and analyzed. The results show that the surface wave acoustic beam is concentrated at the acoustic aperture of the transducer, and the droplets are located at the edge of the acoustic beam. Experimental findings demonstrated that the device was capable of inducing droplet vortex formation with a flow velocity of 3.9 × 10⁻³ m/s. Moreover, the device effectively enriched suspended microspheres and human lymphocytes within the droplet, resulting in a 55-fold increase in cell concentration within 20 seconds.