NDLI: Microcavity assisted acoustic wave channeling can lead to high sensitivity and ultra-low power SAW sensors

Content Provider	IEEE Xplore Digital Library
Author	Koochakzadeh, S. Richardson, M. Bhethanabotla, V.R. Sankaranarayanan, S.K.R.S.
Copyright Year	2015
Description	Author affiliation: Dept. of Chem. & Biomed. Eng., Univ. of South Florida, Tampa, FL, USA (Koochakzadeh, S.; Richardson, M.; Bhethanabotla, V.R.) \|\| Center for Nanoscale Mater., Argonne Nat. Lab., Argonne, IL, USA (Sankaranarayanan, S.K.R.S.)
Abstract	Shear horizontal SAW devices are used as biosensors to detect breast cancer $markers,^{1}$ E. Coli $bacteria,^{2}$ and in DNA hybridization $studies.^{3}$ A current trend in these biosensing systems is to move away from clinical laboratories where expensive bulky equipment and highly skilled personnel are needed and move to point-of-care-testing (POCT). Monitoring a physiological signal such as blood glucose levels in a patient with a wireless sensor provides a good $example.^{4}$ A major challenge to the incorporation of wireless sensors for biosensing/medical applications is maintaining high sensitivity while simultaneously lowering power consumption. Inspired by the concept of phononic crystals (PCs), we introduce a SH-SAW channel sensor based on 90 ° ST-X Quartz substrate where microcavities incorporated in the delay path in the form of periodic inclusions confine acoustic wave propagation to a narrow channel. We utilize a three-dimensional (3-D) finite element model (FEM) to compare acoustic wave propagation characteristics, insertion loss (IL) and mass sensitivity of SAW channel sensors. We show acoustic wave channeling translates into increased sensitivity and reduced power loss. To harness the potential of a SAW channel sensor, we have systematically evaluated properties such as size, periodicity and nature of the filling materials. Tungsten filled cavities show the best performance in terms of device sensitivity. The origin of the improvement in power loss and sensitivity are traced to the acoustic impedance mismatch between the substrate and nature of the filling material in the microcavities. Based on our simulation results, SAW devices with tantalum and $SiO_{2}$ filled microcavities are being fabricated to validate the simulation results. Preliminary experimental results appear promising and suggest that further optimization of microcavities based design variables is needed to realize SAW devices that operate in the ultra-low power range. Our findings thus offer encouraging prospects for designing low power highly sensitive portable biosensors.
Sponsorship	IEEE
Starting Page	1
Ending Page	4
File Size	1213076
Page Count	4
File Format	PDF
e-ISBN	9781479982035
DOI	10.1109/ICSENS.2015.7370391
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2015-11-01
Publisher Place	South Korea
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Microcavities Sensors Surface acoustic waves Surface acoustic wave devices Cavity resonators Sensitivity Finite element method SAW devices Channeling ST-X Quartz
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in