Surface Acoustic Wave Delay Line for Bond Rupture Biosensors

This paper presents the analysis, design, and manufacture of a Surface Acoustic Wave (SAW) delay line for use as a bond-rupture biosensor. Bond-rupture biosensors use acoustic energy to probe the bond strength between the sensor substrate and the analyte. The method of detection of the analyte and its rupture differs depending on the sensor platform. SAW devices are a promising avenue for bond-rupture detection because they can be integrated into optical sensors such as Surface Plasmon Resonance (SPR) as well as the in-built electroacoustic transducers. The prototype device discussed in this paper utilizes the SAW delay line approach, where the analyte changes the properties of the delay path, and the energy of the surface acoustic waves then removes the particles. Design constraints arise from both the manufacturing process and intended application. The developed device is reusable, durable, and able withstand cleaning. Using established Impulse Response models, the SAW device is designed for this application. Experimental results are compared with the simulation predictions and future improvements are considered.