This article presents the design and analysis of a novel dynamic stiffness tuning vibration absorber working with Magnetorheological elastomers (MRE). In this design, the MRE worked in a shear mode, but its MR effect was significantly enhanced by dynamically squeezing the sample thickness with an embedded piezoelectric (PZT) actuator. With this design, both the quasi-static magnetic field and t...

xBaZrO3-(1!x)BaTiO3 solid solutions (x 1⁄4 0, 0.04, 0.06, 0.08, 0.12, and 0.18) synthesized via conventional solid state reaction method exhibit piezoelectric coefficients comparable to those of “hard” PZT-8, PZT-4, and even “soft” PZT-5A. Doping also improves the poling efficiency of xBaZrO3-(1!x)BaTiO3 ceramics. Study of temperature dependence of the dielectric and piezoelectric properties re...

We have investigated probing breast tumor in a lumpectomy sample using a newly developed piezoelectric finger (PEF). PEF is a piezoelectric cantilever that consists of a top driving piezoelectric lead zirconate titanate (PZT) layer and a bottom sensing PZT layer sandwiched to a middle stainless steel layer. A PEF can both apply a force and detect the corresponding displacement in one single dev...

Continuous ultrasonic in-situ monitoring for industrial applications is difficult owing to the high operating temperatures in industrial fields. It is expected that ultrasonic transducers consisting of a CaBi₄Ti₄O15(CBT)/Pb(Zr,Ti)O₃(PZT) sol-gel composite could be one solution for ultrasonic nondestructive testing (NDT) above 500 °C because no couplant is required and CBT has a high Curie tempe...

The active sensing methods using piezoelectric materials have been extensively investigated for the efficient use in structural health monitoring (SHM) applications. Relying on high frequency structural excitations, the methods showed the extreme sensitivity to minor defects in a structure. Recently, a sensor self-diagnostic procedure that performs in situ monitoring of the operational status o...

This paper presents the control performance of a highprecision positioning device using the hybrid actuator composed of a piezoelectric (PZT) actuator and a voice-coil motor (VCM). The combined piezo-VCM actuator features two main characteristics: a large operation range due to long stroke of the VCM, and high precision and heavy load positioning ability due to PZT impact force. A one-degree-of...

Electrocaloric effect is the adiabatic temperature change in a dielectric material when an electric field applied or removed, and it can be considered as alternative refrigeration method. Materials with ferroelectric order exhibit large variations vicinity of phase transition, while antiferroelectrics relaxors may negative electrocaloric effect. In this study, variation polarization was investi...