Piezoelectric sensor

About: Piezoelectric sensor is a research topic. Over the lifetime, 7127 publications have been published within this topic receiving 115903 citations.

A brief review of actuation at the micro-scale using electrostatics, electromagnetics and piezoelectric ultrasonics

Abstract: Though miniaturization and mass production via integrated circuit fabrication techniques have transformed our society, the methods have yet to be successfully applied to the generation of motion, and as a consequence the many potential benefits of microrobotics has yet to be realized. The characteristics of electrostatic, electromagnetic and piezoelectric transduction for generating motion at the micro scale is considered, employing scaling laws and a reasoned consideration of the di!culties in motor fabrication and design using each method. The scaling analyses show that electrostatic, electromagnetic and piezoelectric actuators all have comparable force scaling characteristics of F / L 2 ; if one employs permanent magnets, electromagnetic forces do not scale as F / L 4 . Though the torque, ! , of piezoelectric ultrasonic motors scale rather poorly with ! / L 4 , they have the clear advantage of possessing torque amplitudes some two orders of magnitude larger than motors employing the other transduction schemes at the micro scale.

Characterization of micromachined piezoelectric PZT force sensors for dynamic scanning force microscopy

Abstract: The key component for the piezoelectric scanning force microscopy (SFM) is the piezoelectric force-sensing microcantilever. In this article, the resonance frequency and quality factor of Pb(Ti,Zr)O3 (PZT) microcantilevers; effective Young’s modulus and piezoelectric Pb(Ti,Zr)O3 property of PZT layer of piezoelectric microcantilevers are discussed. The PZT microcantilevers after poling have quality factors such as 204 to 248 in air, and 608 to 1094 in vacuum. The calculated spring constants are in the range of 1.0–30.0 N/m for cantilevers with 0.64–1.7-μm-thick PZT layer and 125–300 μm length. The force sensitivity and resolution of the PZT microcantilever are studied when it is oscillated by an external oscillator and applied to the cyclic contact SFM. Then the real transverse piezoelectric coefficient d31 of piezoelectric PZT thin films is derived from the measured sensitivity and effective Young’s modulus. The derived effective Young’s moduli of PZT layers slightly increases from 53.5 to 58 GPa as the t...

Ultrasonic density sensor for liquids

Abstract: This paper presents an ultrasonic density sensor for liquids that unifies high accuracy with high durability and is suitable for on-line measurements in a wide range of tube diameters. The sensor consists of a transducer with a piezoceramic disk mounted between two reference rods of quartz glass. Additionally, a second transducer is used as a sound receiver. The density is obtained from the reflection coefficient of ultrasound at the interface between the quartz glass rod and the liquid and the transit time of sound between this interface and the second transducer. Parameters, such as high long-term stability and accuracy of /spl plusmn/0.1% of full scale, were obtained by an internal acoustic reference measurement. The reference signal is generated using the sound radiated from the rear side of the piezoceramic disk. Design aspects such as sensor materials and signal-to-noise ratio are discussed, and experimental results are given in this paper. Applications of the sensor include concentration measurement, and ultrasonic mass flow measurement.

A Low-Power Wireless Piezoelectric Sensor-Based Respiration Monitoring System Realized in CMOS Process

Abstract: This paper presents a methodology of monitoring respiration pattern using piezoelectric transducer incorporating CMOS integrated circuits for signal processing and data transmission. As a proof of concept, the system has been tested by placing electrodes on human chest using adhesive hydrogel to detect the pulsatile vibration due to respiration. The system can be used either as a wearable device itself or alternatively can be attached to a jacket or a chest belt. The front-end transducer is a piezoelectric material-based sensor, which is comprised of a ferroelectric polymer named polyvinylidene-fluoride (PVDF). PVDF is also biocompatible, which makes the sensor suitable to be used as a wearable device. The charge produced by the sensor is converted to a proportional voltage signal with the help of a charge amplifier designed in a standard 130-nm CMOS process with eight metal and one poly layer. The analog voltage signal acquired from the charge amplifier is then converted into a digital signal using a reconfigurable pipelined analog-to-digital converter for ease of transmission. An impulse-radio ultra-wideband transmitter operating in the frequency range of 3.1–5 GHz is designed for wireless transmission of the data. The smaller footprint, lighter weight, wireless telemetry, and low-cost material along with the low-power integrated CMOS circuitry for signal processing and data transmission make the proposed system an attractive choice for stable respiration monitoring system.