Effects of Surface-Scanning Detector Position on the Response of a Wireless Magnetoelastic Biosensor

Abstract

This paper investigates the measurement accuracy of a wireless magnetoelastic (ME) biosensor for direct pathogen detection on solid surfaces. The experiments were conducted on the surface of a polyethylene (PE) plate as a model study. An ME biosensor (1mm × 0.2 mm × 30 μm) was placed on the PE surface, and a surface-scanning detector was positioned in the proximity of the sensor for wireless resonant frequency measurement. The detector position was accurately controlled by using a motorized three-axis translation system. The results showed that the resonant frequency variations of the sensor were 125 to +150 Hz for X and Y detector displacements of ± 600 μm and Z displacements of +100 to +500 μm. These resonant frequency variations were small compared to the sensor's initial resonant frequency (< 0.007% of 2.2 MHz initial resonant frequency) measured at the detector home position, indicating high accuracy of the measurement.