&lt;title&gt;Use of piezoelectric resonators for the characterization of mechanical properties of polymers&lt;/title&gt;

Sherrit, Stewart; Olazábal, V.; Sansiñena, J.M.; Bao, Xiaoqi; Chang, Zenghu; Bar‐Cohen, Yoseph

doi:10.1117/12.475175

Cited by 10 publications

(4 citation statements)

References 22 publications

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“…It has been shown earlier that increased mass loading of piezoelectric resonators causes an increase in the electrical impedance at resonant frequency and a decrease in the impedance value at anti-resonant frequency [65,69]. The electrical impedance for the differentiating cells increased at a steeper rate as compared to that for the CGM cells with the culture time at resonant frequency.…”

Section: Resultsmentioning

confidence: 84%

Cell characterization using high frequency ultrasound

Bakshi

Williams

Loboa

et al. 2011

2011 IEEE International Ultrasonics Symposium

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BAKSHI, SAURABH SANJEEV. Cell Characterization Using High Frequency Ultrasound. (Under the direction of Dr.Xiaoning Jiang.) Cell characterization has acquired increasing attention and significance as one of the key steps in tissue engineering and genetic study. This thesis presents a new method of characterizing human stem cells quantitatively and in real-time, by establishing a wellstudied relationship between the electric impedance of a piezoelectric transducer and the acoustic properties of the matching layer. In this case, the matching layer is represented by the stem cell layer, and the cell acoustic impedance is thus obtained by measuring the electric impedance of the piezoelectric resonator on which the cells were grown and chemically induced to undergo osteogenic differentiation. Experiments were conducted with human adipose derive stem cells (hASC) growing on lead magnesium niobate-lead titanate (PMN-PT) resonator plates under in-vitro conditions. A clear change in the electrical impedance of the piezoelectric transducer was observed over a period of 14 days, during which the cells began to deposit calcium, causing a change in the resonator acoustic load. This observed phenomenon is simulated mathematically by the use of a Mason model for transducer design. A MATLAB program was developed based on the Mason equivalent circuit for a piezoelectric resonator behaving under loaded conditions. Cell thickness, sound speed and densities were required as input parameters for running simulations. These were obtained by conducting pulse-echo experiments on the cell layer growing separately in culture wells using a 50 MHz piezoelectric transducer. The simulation was able to show similar resonator behavior as observed from the impedance experiments. This work is thus an initial step in developing a new technique for characterizing cells based on their mechanoacoustic properties.

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Section: Resultsmentioning

confidence: 84%

Cell characterization using high frequency ultrasound

Bakshi

Williams

Loboa

et al. 2011

2011 IEEE International Ultrasonics Symposium

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“…Since the charge focusing design of Fig. 1d has roughly similar amount of metalization, the lower quality factors ob-Literature Value [29] Fitted Value (Room Temperature) (Base Temperature) (Fig. 2, blue trace) to the experimental results shown on Fig.…”

Section: Experimental Techniquesmentioning

confidence: 99%

Electrode configuration and electrical dissipation of mechanical energy in quartz crystal resonators

Välimaa¹,

Santos²,

Ockeloen-Korppi³

et al. 2018

J. Micromech. Microeng.

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Mechanical resonators made with monolithic piezoelectric quartz crystals are promising for studying new physical phenomena. High mechanical quality factors (Q) exhibited by the mm-sized quartz resonators make them ideal for studying weak couplings or long timescales in the quantum regime. However, energy losses through mechanical supports pose a serious limiting factor for obtaining high quality factors. Here we investigate how the Q of quartz resonators at deep cryogenic temperatures can be limited by several types of losses related to anchoring. We first introduce means to reduce the mechanical losses by more than an order of magnitude in a no-clamping scheme, obtaining Qfactors of 10 8 of the lowest shear mode. We can exclude a wide coverage of aluminum metallization on the disk or bond wires as sources of dissipation. However, we find a dramatic reduction of the Q-factor accompanying an electrode configuration that involves strong focusing of the vibrations in the disk center. We propose a circuit model that accounts for the reduced mechanical Q-factor in terms of electrical losses. In particular, we show how the limiting factor for losses can be small ohmic dissipation in a grounding connection, which can be interpreted as electrical anchor losses of the mechanical device.I.

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“…The other method is by way of a Mason equivalent circuits model. The equivalent circuit separates the piezoelectric structure into an electrical port and two acoustic ports through the use of an ideal electromechanical transformer [ 4 ]. It contains information derived from the mathematical statement of the structure, such as the piezoelectric constitutive equation and the motion equation [ 5 ], and gives much faster calculation compared with FEA [ 6 ].…”

Section: Introductionmentioning

confidence: 99%

An Equivalent Circuit of Longitudinal Vibration for a Piezoelectric Structure with Losses

Yuan

Fan

2018

Sensors

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Equivalent circuits of piezoelectric structures such as bimorphs and unimorphs conventionally focus on the bending vibration modes. However, the longitudinal vibration modes are rarely considered even though they also play a remarkable role in piezoelectric devices. Losses, especially elastic loss in the metal substrate, are also generally neglected, which leads to discrepancies compared with experiments. In this paper, a novel equivalent circuit with four kinds of losses is proposed for a beamlike piezoelectric structure under the longitudinal vibration mode. This structure consists of a slender beam as the metal substrate, and a piezoelectric patch which covers a partial length of the beam. In this approach, first, complex numbers are used to deal with four kinds of losses—elastic loss in the metal substrate, and piezoelectric, dielectric, and elastic losses in the piezoelectric patch. Next in this approach, based on Mason’s model, a new equivalent circuit is developed. Using MATLAB, impedance curves of this structure are simulated by the equivalent circuit method. Experiments are conducted and good agreements are revealed between experiments and equivalent circuit results. It is indicated that the introduction of four losses in an equivalent circuit can increase the result accuracy considerably.

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<title>Use of piezoelectric resonators for the characterization of mechanical properties of polymers</title>

Cited by 10 publications

References 22 publications

Cell characterization using high frequency ultrasound

Cell characterization using high frequency ultrasound

Electrode configuration and electrical dissipation of mechanical energy in quartz crystal resonators

An Equivalent Circuit of Longitudinal Vibration for a Piezoelectric Structure with Losses

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