Department of Chemistry - PhD Student Seminar - Surface Acoustic Wave as Powerful Biochemical Sensing Probes and Actuating Tools

Student: Mr. Yuekang LI

Department: Department of Chemistry, HKUST

Supervisor: Prof. Hongkai WU

Abstract

Surface acoustic waves (SAWs) have emerged as powerful platforms for biomedical sensing and microscale actuation due to their unique ability to confine acoustic energy near material surfaces. Unlike conventional bulk acoustic waves, SAWs exhibit exponentially decaying energy distribution into the substrate, enabling high sensitivity toward surface perturbations while maintaining efficient energy utilization. This seminar will introduce the fundamental principles of SAW propagation, including commonly applied wave modes such as Rayleigh, shear horizontal, Lamb, and Love waves, and discuss their distinct characteristics and suitability for different applications.

The generation and detection of SAWs through piezoelectric effects and interdigital electrode structures will be presented, followed by an overview of their application in biosensing. By converting surface interactions, including molecular binding and mass or conductivity changes, into measurable acoustic responses, SAW devices have demonstrated promising capabilities for detecting biological targets such as nucleic acids and proteins. In addition, the role of Rayleigh-wave-driven acoustic streaming and pressure-field generation in particle manipulation and microfluidic actuation will be discussed.

Finally, the seminar will highlight future opportunities for SAW technology, including flexible devices, wearable biosensors, wireless implantable systems, and highly integrated platforms for advanced biomedical monitoring and molecular-level detection.