Thermal management strategies for high-power surface acoustic wave actuators: pulsed driving, optimal thickness, and heat sink integration

High-power surface acoustic wave (SAW) actuators encounter thermal challenges, including frequency drift and structural fracture, that limit microfluidic applications. This study presents an integrated thermal management strategy that combines pulsed driving, geometric optimization, and heat sink incorporation to achieve stable high-power operation. This approach involves independent control of heat generation, accumulation, and dissipation. Specifically, programmable RF pulses (0.1–100 Hz, 50% duty cycle) precisely control heat generation timing, reducing peak temperatures by 50% and facilitating drop-on-demand ejection. Optimizing substrate thickness (0.5–2 mm) manages heat capacity and thermal resistance, balancing rapid thermal response with steady-state performance. Minimizing the aperture of the interdigital transducers (IDTs) to 0.5 mm increases power density to the atomization threshold (9 W/mm 2 ) without extra heat input. Applying thermally conductive silver grease with a copper heat sink and forced air cooling enhances dissipation, reducing temperature gradients by 66 °C and thermal stress by 62%. This multifaceted approach extends operation to 20 W for over 1 h, as validated by infrared thermography and finite element simulations. This study provides a comprehensive solution and offers fundamental insights for high-power SAW applications such as lung drug atomization.