This paper describes the design of an ultrasonic transducer using different lead-free piezoelectric materials and evaluates their performance in the human blood medium. COMSOL Multiphysics 5.1 is used for the simulation study, where a 2D axis-symmetric model geometry of a piezoelectric transducer was designed with lead-free piezoelectric materials such as barium niobate (Ba2NaNb5O15) (BNN), barium titanate (BaTiO3), lithium niobate (LiNbO3) (LN), and zinc oxide. These piezoelectric materials are capable of being used as thin films. The potential of 1.6 volts at a 350 MHz frequency was applied to the device. The geometry of the sample container for blood is a sector with a 90-degree angle and a radius of 3 micrometers. The surface and radial displacement of the transducer structure of the materials with pressure and stress are studied in liquid blood medium

1. COMPARATIVE ANALYSIS OF LEAD FREE PIEZOELECTRIC MATERIAL FOR
ULTRSONIC GLUCOSE SENSING APPLICATIONS
1

2. Abstract
This Paper describes the design of an ultrasonic transducer using different lead free piezo-
electric materials and evaluates their performance in the human blood medium. COMSOL
Multiphysics 5.1 is used for the simulation study where a 2D axis- symmetric model geometry of
piezoelectric transducer was designed with lead free piezoelectric materials such as Barium
Sodium Niobate (Ba2NaNb5O15)(BNN), Barium Titanate (BaTiO3), Lithium Niobate (LiNbO3)
(LN) and zinc oxide. These piezoelectric materials are capable of being used as thin films. The
potential of 1.6 Volt with 350MHz frequency was applied to the device. The geometry of the
sample container for blood is a sector with 90 degrees and radius of 3 micrometers. The surface and
radial displacement of the transducer structure of the materials with pressure and stress are studied
in liquid blood medium. The ultrasonic transducer with these piezo materials was observed
showing different transducer response in the blood medium and therefore, it can be used to measure
the glucose levels in the human blood. However, the Zno has shown better performance compared
to others. The glucose level of blood samples were also compared with a commercial glucometer.
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3. Introduction
• To prevent complications in diabetes, accurate monitoring of blood glucose
levels is important.
• Regular monitoring of sugar level in patient can alarm many unwanted rise
in the level and necessary precautions can be taken at the right time .
• Glucose meters are supposed to be a solution for continuous monitoring of
sugar level.
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4. Different techniques for glucose monitoring:
Invasive Minimally invasive
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5. Present techniques (Non-Invasive methods):
• Infrared and Near-infrared absorption spectroscopy
• Near-infrared scattering technique
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6. December 22, 2023 ICACT19-EC-70 6
 Photo acoustic spectroscopy
Bio impedance spectroscopy
Cont…

7. Biosensor
• A sensor that integrates a biological element with physiochemical
transducer to produce an electronic signal proportional to signal analyte
which is then conveyed to detector
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8. Ultrasonic transducer method can be used to determine the
glucose levels of human blood by studying the variation of
amplitude with density of blood sample with glucose and it can
be calibrated and compared to determine the sugar level.
Ultrasonic Transducer Model for Biosensor
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9. Ultrasonic:
It is a phenomenon that has the frequency above the hearing capability of
human ear.
• Ultrasonic transducer
It is a device that converts energy into ultrasonic waveform and vice versa
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10. Piezoelectric materials:-
• Offer a high pressure per density ratio for the actuator,
• High stability in hostile environment
• Chemically they are very stable.
For making ultrasonic transducers and piezoelectric actuators, it is
desirable to have
• High electromechanical coupling coefficients
• Relatively large dielectric constant
• Large piezoelectric coefficient.
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11. Lead free Piezo Materials
 Lead Zirconate Titanate (PZT) has been recognized as an environmentally
non-friendly material which contains more than 60% lead by weight .
 Unfortunately, among the existing lead-free ferroelectric crystals, some
have weak piezoelectricity and some are very expensive to fabricate.
 Different lead free piezoelectric materials like
◦ Barium Sodium Niobate (Ba2NaNb5O15)(BNN),
◦ Barium Titanate (BaTiO3)(BT)
◦ Lithium Niobate (LiNbO3) (LN)
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12.  Conventional ultrasonic transducer systems became very bulky and power
hungry.
 Hence we switched over to Micro-electro mechanical system (MEMS)
 MEMS based acoustic bio-sensing transducer is based on the piezoelectric
technology which exploits the nature and properties of the propagating
ultrasonic wave in blood medium of various densities
MEMS
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13. Model geometry and boundary conditions of
ultrasonic transducer
Fig 1: 2D axis symmetry
model
Fig 2:Pressure acoustics
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14. Piezoelectric film under stress
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15. 15
Acoustic pressure waveforms
Fig 3: Pressure acoustic wave form Fig 4: sound acoustic waveform
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16. Acoustic pressure wave form (BNN)
Fig 5: Pressure acoustic wave form of BNN Fig 6: sound acoustic waveform of BNN
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17. Acoustic pressure wave form (BT)
Fig 7: Pressure acoustic wave form of BT Fig 8: sound acoustic waveform of BT
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18. Acoustic pressure wave form (LN)
Fig 9: Pressure acoustic wave form of LN Fig 10: sound acoustic waveform of LN
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19. Acoustic pressure wave form (Zn)
Fig 11: Pressure acoustic wave form of ZN Fig 12: sound acoustic waveform of ZN
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20. Far field polar graphs for BNN
Fig 13: Far field pressure polar graph BNN Fig 14: Far field sound polar graph BNN
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21. Far field polar graphs BT
Fig15: Far field pressure polar graph BT Fig 16:Far field sound polar graph BT
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22. Far field polar graphs(LN)
Fig17: Far field pressure polar graph LN Fig 18:Far field sound polar graph LN
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23. Far field polar graphs(ZN)
Fig 19:Far field pressure polar graph ZN Fig 20:Far field sound polar graph ZN
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24. Comparison between lead and lead-free materials
0
1
2
3
4
0 2 4 6
Zno
Pzt
blood sample Zno Pzt
1
3.47 3.35
2
0.8675 0.795
3
0.3855 0.2575
4
0.2168 0.1568
5
0.138 0.075
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25. Blood
Sample
Pressure
generated by
LIN
Pressure
generated by
BNN
Pressure
generated by
BT
Pressure
generated by
Zno
1 -255.2156377 -1564.508718 -3765.337914 -349.1934105
2 -255.2495062 -1564.715697 -3765.832407 -361.2346103
3 -255.4140098 -1565.721021 -3768.234204 -368.2795124
4 -255.590608 -1566.800254 -3770.812553 -373.2788144
5 -255.8663893 -1568.485608 -3774.838906 -377.2024183
Comparison between lead-free materials
1
2
3
4
5
Lin
BNN
BT
Zno
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26. Conclusion
• From the property of different lead free piezoelectric materials with
different glucose concentrations of blood sample medium displacement and
pressure are simulated using software COMSOL Multiphysics 5.1.
• It was found that Zno has shown better performance compare to others.
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27. References
 Pra dhan S K., Kamilla S K, Das, D P (2012), “Studies of Lead Free Piezo-Electric Materials Based Ultrasonic MEMS
Model for Bio Sensor”, In Proceeding of COMSOL Conference,ISBN: 978-0-9839688-2-5.
• Eun-Joo Park, Jacob Werner, Joshua Beebe, Samantha Chan, Nadine Barrie Smith, “Noninvasive Ultrasonic Glucose Sensing
with Large Pigs (~200 Pounds) Using a Lightweight Cymbal Transducer Array and Biosensors” Journal of Diabetes Science
and Technology, 3(3), pp-517-523, (2009).
• D.W.Greve, I.J. Oppenheim, “Coupling of MEMS Ultrasonic Transducer”, Proceedings of IEEE, Sensors, (2), pp 814 – 819,
(2003).
• K.Miranji, Dr R sandanalakshmi., “A Technology Overview and Future Scope of Bio-Mems in Tropical Disease Detection:
Review”
• Tao Li, Yanhong Chen, and Jan Ma,” Development of a Miniaturized Piezoelectric Ultrasonic Transducer” IEEE Transactions
on Ultrasonic's, Ferroelectrics, and Frequency Control, 56 (3), 649-659, (2009).
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Thank You…..