An extended Butterworth-Van Dyke (EBVD) model to characterize a thickness-shear mode quartz cryst... more An extended Butterworth-Van Dyke (EBVD) model to characterize a thickness-shear mode quartz crystal resonator in a semi-infinite viscoelastic medium is derived by means of analysis of the lumped elements model described by Cernosek et al. [R. W. Cernosek, S. J. Martin, A. R. Hillman, and H. L. Bandey, IEEE Trans. Ultrason. Ferroelectr. Freq. Control 45, 1399 (1998)]. The EBVD model
A new electronic design for continuous motional series resonant frequency monitoring of loaded qu... more A new electronic design for continuous motional series resonant frequency monitoring of loaded quartz crystal resonators is presented. Using this circuit, a low-cost method for a simple determination of equivalent circuit parameters of quartz crystal resonators is described. Measurements made with the proposed system on typical AT cut quartz crystals are in good agreement with those of an Impedance Analyzer.
ABSTRACT The bulk acoustic wave — thickness shear mode resonator (BAW-TSM), whose major represent... more ABSTRACT The bulk acoustic wave — thickness shear mode resonator (BAW-TSM), whose major representative is the AT-cut quartz crystal, has been introduced in Chap. 1 as a microbalance sensor (QCM). In chapter 4, the basic concepts of modeling were introduced making the use of the resonator evident as a sensor device. Figure 4.1 showed the general schema of a quartz crystal resonator with a multilayer coating, which can be reduced to that of Fig. 16.1 by modeling a 3-layer compound resonator formed by the quartz crystal in contact with a finite viscoelastic layer contacting a semi-infinite viscoelastic medium. This reduced model is appropriate for representing a large number of applications. Changes in the physical properties of the coating are transferred to the electrical admittance or impedance of the resonator, through the acoustic load impedance Z L , (see Chap. 4 and Appendix 4.A), thus allowing its use as a sensor device.
IEEE International Frequency Control Symposium, 2011
Quartz crystal microbalance (QCM) technique is widely used in in-liquid biochemical applications.... more Quartz crystal microbalance (QCM) technique is widely used in in-liquid biochemical applications. The main challenges remain on the improvement of sensitivity and limit of detection, as well as multianalysis capabilities and reliability. The improvement of sensitivity has been addressed in the last decades by increasing the sensor fundamental frequency; following the increment of the frequency/mass sensitivity with the square of
2007 IEEE International Frequency Control Symposium Joint with the 21st European Frequency and Time Forum, 2007
... di Elettronica per l'Automazione and INFM Università di Brescia Brescia, Italy vittorio.... more ... di Elettronica per l'Automazione and INFM Università di Brescia Brescia, Italy vittorio.ferrari@ unibs.it ... However a more detailed analysis makes clear the effect of the different phase response of the amplifiers A1 and A2 for gains different from 1. Effectively, the relative errors, ε ...
In spite of being widely used for in liquid biosensing applications, sensitivity improvement of c... more In spite of being widely used for in liquid biosensing applications, sensitivity improvement of conventional (5-20MHz) quartz crystal microbalance (QCM) sensors remains an unsolved challenging task. With the help of a new electronic characterization approach based on phase change measurements at a constant fixed frequency, a highly sensitive and versatile high fundamental frequency (HFF) QCM immunosensor has successfully been developed and tested for its use in pesticide (carbaryl and thiabendazole) analysis. The analytical performance of several immunosensors was compared in competitive immunoassays taking carbaryl insecticide as the model analyte. The highest sensitivity was exhibited by the 100MHz HFF-QCM carbaryl immunosensor. When results were compared with those reported for 9MHz QCM, analytical parameters clearly showed an improvement of one order of magnitude for sensitivity (estimated as the I50 value) and two orders of magnitude for the limit of detection (LOD): 30μgl(-1) vs 0.66μgL(-1)I50 value and 11μgL(-1) vs 0.14μgL(-1) LOD, for 9 and 100MHz, respectively. For the fungicide thiabendazole, I50 value was roughly the same as that previously reported for SPR under the same biochemical conditions, whereas LOD improved by a factor of 2. The analytical performance achieved by high frequency QCM immunosensors surpassed those of conventional QCM and SPR, closely approaching the most sensitive ELISAs. The developed 100MHz QCM immunosensor strongly improves sensitivity in biosensing, and therefore can be considered as a very promising new analytical tool for in liquid applications where highly sensitive detection is required.
In this paper, the sensitivity of a quartz crystal microbalance (QCM) sensor is analysed and disc... more In this paper, the sensitivity of a quartz crystal microbalance (QCM) sensor is analysed and discussed in terms of the phase change versus the surface mass change, instead of the classical sensitivity in terms of the resonant frequency change derived from the well-known Sauerbrey equation. The detection sensitivity derived from the Sauerbrey equation is a theoretical detection capability in terms
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2000
An extended Butterworth-Van Dyke (EBVD) model with frequency-independent parameters for the chara... more An extended Butterworth-Van Dyke (EBVD) model with frequency-independent parameters for the characterization of a resonant compound formed by a quartz crystal in contact with a finite viscoelastic layer contacting a semi-infinite viscoelastic medium is extracted by analysis of the lumped element model. The formulation of the EBVD model is compared with the complete expression of the electrical admittance of the loaded quartz derived from the transmission line model (TLM). Relative deviations between them do not exceed 3% around 1% bandwidth near resonance. An extended Martin & Granstaff's model and an explicit expression for the frequency shift that supposes an extension of Kanazawa's model for viscoelastic media are obtained. An analysis of the errors associated with the extraction of shear parameters of the coating for different materials prove that, to obtain an error less than 5% in the shear parameters determination, the viscoelastic contribution, defined as the relative error in the thickness computed from the frequency shift by Sauerbrey equation, must be greater than a limit that depends on Q, which is defined as the ratio of the shear storage modulus (G') to shear loss modulus (G"). In the materials studied, polymers in the transition range or in the rubbery state with Q = 1 and 10, the viscoelastic contribution must be higher than 15% and 50%, respectively, for a 5% limit error in the shear parameters extraction. A criterion for a practical determination of the appropriate viscoelastic regimes is indicated.
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2000
The problem of coating properties extraction in quartz crystal resonator (QCR) applications is on... more The problem of coating properties extraction in quartz crystal resonator (QCR) applications is one of the challenging tasks of QCR applications, not completely solved even in theoretical conditions. The present work demonstrates that the problem is determined only for a set of three parameters of the coating, which concentrate the four coating properties. The following parameters are chosen: the surface mass density m8 = p1h1, the loss tangent tan delta1 = G''1/G'1, and the magnitude of the characteristic impedance /Z1(c)/ = (p1/G1/)(1/2). An algorithm is proposed that permits, in ideal conditions, an unambiguous extraction of these parameters, starting only from the admittance spectrum of a three-layer compound resonator, obtained from the one-dimensional transmission-line model (TLM) around the resonance. The algorithm introduces three additional improvements in relation to other routines: the calculation time is drastically reduced, the problem of erroneous solutions related to relative minima in typical fitting routines is eliminated, and a systematic error analysis in the extraction of the coating properties in real practice can be carried out. The use of the proposed algorithm as a tool for studying the effects of different phenomena such as slipping or surface roughness is introduced.
The classical quartz crystal microbalance (QCM) is no longer only a microbalance; it has got a pl... more The classical quartz crystal microbalance (QCM) is no longer only a microbalance; it has got a place as an acoustic sensor in a broad range of applications such as: fluid physical characterization, viscoelastic study of polymers, charge transfer analysis in electrochemical processes, and detection of biological components in fluid media, among other applications. In this paper, the basic operation of
An extended Butterworth-Van Dyke (EBVD) model to characterize a thickness-shear mode quartz cryst... more An extended Butterworth-Van Dyke (EBVD) model to characterize a thickness-shear mode quartz crystal resonator in a semi-infinite viscoelastic medium is derived by means of analysis of the lumped elements model described by Cernosek et al. [R. W. Cernosek, S. J. Martin, A. R. Hillman, and H. L. Bandey, IEEE Trans. Ultrason. Ferroelectr. Freq. Control 45, 1399 (1998)]. The EBVD model
A new electronic design for continuous motional series resonant frequency monitoring of loaded qu... more A new electronic design for continuous motional series resonant frequency monitoring of loaded quartz crystal resonators is presented. Using this circuit, a low-cost method for a simple determination of equivalent circuit parameters of quartz crystal resonators is described. Measurements made with the proposed system on typical AT cut quartz crystals are in good agreement with those of an Impedance Analyzer.
ABSTRACT The bulk acoustic wave — thickness shear mode resonator (BAW-TSM), whose major represent... more ABSTRACT The bulk acoustic wave — thickness shear mode resonator (BAW-TSM), whose major representative is the AT-cut quartz crystal, has been introduced in Chap. 1 as a microbalance sensor (QCM). In chapter 4, the basic concepts of modeling were introduced making the use of the resonator evident as a sensor device. Figure 4.1 showed the general schema of a quartz crystal resonator with a multilayer coating, which can be reduced to that of Fig. 16.1 by modeling a 3-layer compound resonator formed by the quartz crystal in contact with a finite viscoelastic layer contacting a semi-infinite viscoelastic medium. This reduced model is appropriate for representing a large number of applications. Changes in the physical properties of the coating are transferred to the electrical admittance or impedance of the resonator, through the acoustic load impedance Z L , (see Chap. 4 and Appendix 4.A), thus allowing its use as a sensor device.
IEEE International Frequency Control Symposium, 2011
Quartz crystal microbalance (QCM) technique is widely used in in-liquid biochemical applications.... more Quartz crystal microbalance (QCM) technique is widely used in in-liquid biochemical applications. The main challenges remain on the improvement of sensitivity and limit of detection, as well as multianalysis capabilities and reliability. The improvement of sensitivity has been addressed in the last decades by increasing the sensor fundamental frequency; following the increment of the frequency/mass sensitivity with the square of
2007 IEEE International Frequency Control Symposium Joint with the 21st European Frequency and Time Forum, 2007
... di Elettronica per l'Automazione and INFM Università di Brescia Brescia, Italy vittorio.... more ... di Elettronica per l'Automazione and INFM Università di Brescia Brescia, Italy vittorio.ferrari@ unibs.it ... However a more detailed analysis makes clear the effect of the different phase response of the amplifiers A1 and A2 for gains different from 1. Effectively, the relative errors, ε ...
In spite of being widely used for in liquid biosensing applications, sensitivity improvement of c... more In spite of being widely used for in liquid biosensing applications, sensitivity improvement of conventional (5-20MHz) quartz crystal microbalance (QCM) sensors remains an unsolved challenging task. With the help of a new electronic characterization approach based on phase change measurements at a constant fixed frequency, a highly sensitive and versatile high fundamental frequency (HFF) QCM immunosensor has successfully been developed and tested for its use in pesticide (carbaryl and thiabendazole) analysis. The analytical performance of several immunosensors was compared in competitive immunoassays taking carbaryl insecticide as the model analyte. The highest sensitivity was exhibited by the 100MHz HFF-QCM carbaryl immunosensor. When results were compared with those reported for 9MHz QCM, analytical parameters clearly showed an improvement of one order of magnitude for sensitivity (estimated as the I50 value) and two orders of magnitude for the limit of detection (LOD): 30μgl(-1) vs 0.66μgL(-1)I50 value and 11μgL(-1) vs 0.14μgL(-1) LOD, for 9 and 100MHz, respectively. For the fungicide thiabendazole, I50 value was roughly the same as that previously reported for SPR under the same biochemical conditions, whereas LOD improved by a factor of 2. The analytical performance achieved by high frequency QCM immunosensors surpassed those of conventional QCM and SPR, closely approaching the most sensitive ELISAs. The developed 100MHz QCM immunosensor strongly improves sensitivity in biosensing, and therefore can be considered as a very promising new analytical tool for in liquid applications where highly sensitive detection is required.
In this paper, the sensitivity of a quartz crystal microbalance (QCM) sensor is analysed and disc... more In this paper, the sensitivity of a quartz crystal microbalance (QCM) sensor is analysed and discussed in terms of the phase change versus the surface mass change, instead of the classical sensitivity in terms of the resonant frequency change derived from the well-known Sauerbrey equation. The detection sensitivity derived from the Sauerbrey equation is a theoretical detection capability in terms
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2000
An extended Butterworth-Van Dyke (EBVD) model with frequency-independent parameters for the chara... more An extended Butterworth-Van Dyke (EBVD) model with frequency-independent parameters for the characterization of a resonant compound formed by a quartz crystal in contact with a finite viscoelastic layer contacting a semi-infinite viscoelastic medium is extracted by analysis of the lumped element model. The formulation of the EBVD model is compared with the complete expression of the electrical admittance of the loaded quartz derived from the transmission line model (TLM). Relative deviations between them do not exceed 3% around 1% bandwidth near resonance. An extended Martin & Granstaff's model and an explicit expression for the frequency shift that supposes an extension of Kanazawa's model for viscoelastic media are obtained. An analysis of the errors associated with the extraction of shear parameters of the coating for different materials prove that, to obtain an error less than 5% in the shear parameters determination, the viscoelastic contribution, defined as the relative error in the thickness computed from the frequency shift by Sauerbrey equation, must be greater than a limit that depends on Q, which is defined as the ratio of the shear storage modulus (G') to shear loss modulus (G"). In the materials studied, polymers in the transition range or in the rubbery state with Q = 1 and 10, the viscoelastic contribution must be higher than 15% and 50%, respectively, for a 5% limit error in the shear parameters extraction. A criterion for a practical determination of the appropriate viscoelastic regimes is indicated.
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2000
The problem of coating properties extraction in quartz crystal resonator (QCR) applications is on... more The problem of coating properties extraction in quartz crystal resonator (QCR) applications is one of the challenging tasks of QCR applications, not completely solved even in theoretical conditions. The present work demonstrates that the problem is determined only for a set of three parameters of the coating, which concentrate the four coating properties. The following parameters are chosen: the surface mass density m8 = p1h1, the loss tangent tan delta1 = G''1/G'1, and the magnitude of the characteristic impedance /Z1(c)/ = (p1/G1/)(1/2). An algorithm is proposed that permits, in ideal conditions, an unambiguous extraction of these parameters, starting only from the admittance spectrum of a three-layer compound resonator, obtained from the one-dimensional transmission-line model (TLM) around the resonance. The algorithm introduces three additional improvements in relation to other routines: the calculation time is drastically reduced, the problem of erroneous solutions related to relative minima in typical fitting routines is eliminated, and a systematic error analysis in the extraction of the coating properties in real practice can be carried out. The use of the proposed algorithm as a tool for studying the effects of different phenomena such as slipping or surface roughness is introduced.
The classical quartz crystal microbalance (QCM) is no longer only a microbalance; it has got a pl... more The classical quartz crystal microbalance (QCM) is no longer only a microbalance; it has got a place as an acoustic sensor in a broad range of applications such as: fluid physical characterization, viscoelastic study of polymers, charge transfer analysis in electrochemical processes, and detection of biological components in fluid media, among other applications. In this paper, the basic operation of
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