High-throughput acoustofluidic device driven by an ElLIPtical Reflector Focusing Ultrasonic TranSducer (ELIPS)

Acoustofluidics is a promising technique for microparticle manipulation and has potential applications across various fields. However, its relatively low throughput limits wider applications. To overcome this challenge, we propose an ElLIPtical reflector focusing ultrasonic tranSducer (ELIPS) to drive bulk-wave-acoustofluidic devices, enabling high throughput. The ELIPS focuses transverse waves converted from longitudinal waves onto the chip sidewall. Simulations show that device efficiency increases by more than a factor of two, while the temperature rise is reduced by approximately 80 % compared to conventional devices driven by lead zirconate titanate (PZT) elements. Vibration amplification of the ELIPS is also confirmed at multiple resonance frequencies in simulations. Flow experiments demonstrate the high throughput of the ELIPS-driven device, which can perfectly focus 5-μm-diameter polystyrene particle at a flow rate of 5 mL/min with the input power of only 1.7 W, outperforming PZT-driven devices. Furthermore, the ELIPS-driven device also exhibits excellent thermal stability and biocompatibility, reducing the temperature rise of the PZT and the chip by approximately 60 % and 80 %, respectively, compared to two conventional devices. Measurements of vibration velocity confirm a 1.5-fold vibration amplification at the optimal frequency for particle focusing and a 1.8–2.1 times amplification at the ELIPS resonance frequencies. This suggests that aligning the channel resonance frequency with one of the ELIPS resonance frequencies may further enhance throughput. The results highlight the ELIPS as an effective solution for improving the performance of acoustofluidic devices, serving both as a focusing waveguide and a heat sink. • Propose a novel transducer to enhance the throughput of acoustofluidic devices. • Increase the acoustic energy density compared to conventional PZT-driven devices. • Efficiently focus 5-μm polystyrene particles at 5 mL/min with only 1.7 W of power. • Exhibit superior heat management with minimum temperature rise across the device.