Low Insertion Loss and Highly Sensitive SH-SAW Sensors Based on 36° YX LiTaO3 Through the Incorporation of Filled Microcavities
Reduction in power consumption and improvement in mass sensitivity are important considerations for surface acoustic wave (SAW) devices used in various sensing applications. Detection of minute quantities of a particular species (clinical sensing) and power requirements (wireless sensing) are two key metrics that must be optimized. In this paper, a 3-D finite element model (FEM) was employed to compare insertion loss (IL) and mass sensitivity of SAW sensors having microcavities filled with ZnO and nanocrystalline diamond to a standard two-port SAW design. Initial simulation results show that ZnO filled cavities (depth = 5 mu m) were most effective at reducing power loss Delta IL = (6.03 dB) by increasing particle displacement (acousto-electric to mechanical transduction) at the output transducer. A 100-pg/cm(2) load was applied to the sensing area of each device to evaluate mass sensitivity. Our simulations suggest that ZnO filled cavities with shallow depth (2.5 mu m) have the greatest sensitivity. The FEM simulations are used to understand the acoustic wave propagation in microcavity-based SAW sensors. The observed enhancement in mass sensitivity and power transfer is attributed to waveguiding effects and constructive interference of the scattered acoustic waves from the microcavities. Devices fabricated with microcavities similar to 1 mu m deep decreased IL by 3.306 dB compared with a standard SAW device. Additional simulations were conducted for each device configuration using the same depth in order to make a direct comparison between measured and simulated results. Our findings offer encouraging prospects for designing low IL highly sensitive microcavity-based SAW biosensors.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science - Office of Basic Energy Sciences - Scientific User Facilities Division
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1392669
- Journal Information:
- IEEE Sensors Journal, Vol. 15, Issue 2; ISSN 1530-437X
- Publisher:
- IEEE
- Country of Publication:
- United States
- Language:
- English
Similar Records
Shear-horizontal surface acoustic wave phononic device with high density filling material for ultra-low power sensing applications
Stability of Pt/Al2O3-Based Electrode Langasite SAW Sensors with Al2O3 Capping Layer and Yttria-Stabilized Zirconia Sensing Layer