In recent years, surface acoustic wave (SAW) sensors have been widely used in the field of biochemical detection, such as the detection of biological cells, macromolecules, aerosols, and other substances. In these cases, the shape and distribution of the object to be measured are usually non-uniform, and the non-uniformity of the load causes great interference to the simulation of the SAW sensor.
In order to simulate the SAW sensor under non-uniform loads accurately, researchers from the Institute of Acoustics of the Chinese Academy of Sciences (IACAS) proposed a two-dimensional analysis method for the sensitive area of the sensor, and realized the effective simulation of several kinds of non-uniform loads.
In this method, the sensitive area of a SAW sensor was divided into two dimensions. Combining with the P-matrix model, researchers transformed the sensitive area into a two-dimensional P-matrix array, which composed of several sensitive elements. By configuring the P-matrix of each sensitive unit independently, the effective simulation of various complex distributed loads could be realized.
Researchers designed four load patterns with different distributions and carried out simulation and experiment respectively. The results showed that the transversal non-uniformity of the load affected the main peak shape of the frequency response of the sensor. The longitudinal non-uniformity of the load had an effect on the center frequency of the sensor. The frequency response of the sensor obtained by simulation in each mode was consistent with the measured frequency response, which proved the accuracy of the method.
This research provides an idea for dealing with the detection of complex load pattern, and helps to expand the further application of the SAW sensors in the field of biochemical detection.
The research, published online in academic journal SENSORS AND ACTUATORS A-PHYSICAL, is supported by the National Natural Science Foundation of China (No. 12074404).
Figure 1. 2D segmentation of sensitive area of SAW sensor. (Image by IACAS)
Figure 2. Simulation results (left), experimental results (right). (Image by IACAS)
YOU Ran, LIU Jiuling, LIU Minghua, HE Shitang. Detecting of non-uniformly distributed loads with SAW sensors using a two-dimensional segmentation method. Sensors and Actuators A: Physical, 2021. DOI: 10.1016/j.sna.2021.112728
Institute of Acoustics, Chinese Academy of Sciences, 100190 Beijing, China