Vibration Characteristics of Trident-Type Tuning-Fork Resonator in the Second Flexural Mode for Application to Tactile Sensors

A new method is presented for detecting a small-scale variation in liquid level using an energy-trapping phenomenon in piezoelectric thickness-mode vibrators. In a piezoelectric plate operating in a trapped-energy mode, an evanescent field is created in the surrounding region of the plate. When this region is dipped in a liquid, a small leakage of vibration energy occurs. The amount of leakage varies depending on how deep the surrounding region is in the liquid. Therefore, small variations in liquid level are detected by observing the changes in the electric characteristics of the vibrators, such as quality factor and the electric conductance G. Preliminary experiments have shown that almost linear variations in G against dipping depth can be obtained within a few millimeter range.

mentioning

confidence: 99%

Liquid-Level Sensing by Trapped-Energy-Mode Thickness Vibration

Yamada

Honda

Horiuchi

et al. 2009

“…260,277,278) As described in the previous section, piezoelectric devices can be modulator-type sensors, in which the target phenomena affect the signals from the devices. In this way, piezoelectric devices can be used as mechanical sensors such as force sensors, [279][280][281][282][283][284][285] object detection sensors, [286][287][288] acceleration sensors, [289][290][291][292][293] and gyro sensors. [294][295][296][297][298][299] In these sensors, direct forces or inertial forces are applied to a vibrating resonator, so that the output signal is modulated such as its resonance frequency.…”

Section: Theorymentioning

confidence: 99%

Introduction of measurement techniques in ultrasonic electronics: Basic principles and recent trends

Mizutani¹,

Wakatsuki²,

Ebihara³

2016

Measurementthe act of measuring physical properties that we performhas the potential to contribute to the successful advancement of sciences and society. To open doors in physics and other sciences, various measurement methods and related applications have been developed, and ultrasound has remained a useful probe, power source, and interesting measurement object for the past two centuries. In this paper, we first summarize the basic principles of ultrasound from the viewpoint of measurement techniques for readers who just have started studying or are interested in the field of ultrasonic electronics. Moreover, we also introduce recent studiesultrasonic properties of materials, measurement techniques, piezoelectric devices, nonlinear acoustics, biomedical ultrasound, and ocean acousticsand their trends related to measurement techniques in ultrasonic electronics to provide some ideas for related applications.

“…3,4) On the other hand, when we pay more attention to liquids other than a solid material, the viscosity measurement of liquids using ultrasonic relaxation or piezoelectric vibration has also been conducted. 5,6) To date, vibrating tactile sensors using the change in frequency [7][8][9][10][11][12][13][14][15][16][17][18] and resistance 19,20) have been studied. To the best of our knowledge, our vibrating tactile sensor using the change in motional capacitance 21,22) is the first one.…”

Section: Introductionmentioning

confidence: 99%

Analysis of change in motional capacitance of electrical equivalent circuit of quartz-crystal tuning-fork tactile sensor induced by viscoelastic materials in contact with its base

Hatakeyama¹

2014

We investigated experimentally and theoretically the change in the reciprocal of the motional capacitance Δ(1/Ca) of a quartz-crystal tuning-fork tactile sensor before and after its base comes into contact with neoprene rubbers. We derived the analytical formula for the motional capacitance of the electrical equivalent circuit of the sensor at resonance based on the combination of the L-shaped bar model and viscoelastic foundation model, and the law energy of conservation. We found from both contact experiments and theoretical considerations on the analytical formula that Δ(1/Ca) is intrinsically induced by both the dynamic Young’s modulus and viscosity of neoprene rubbers at 32.5 kHz, which is the actual resonant frequency of the quartz tactile sensor. In this paper, we showed experimentally and theoretically for the first time that the motional capacitance of the tuning fork tactile sensor is affected by the dynamic viscosity of materials in contact with the sensor’s base, except their dynamic Young’s modulus.