Enhanced piezoelectric properties and thermal stability of LiNbO_(3)-modified PNN-PZT ceramics

Piezoelectric PZT ceramics with high piezoelectric properties and good thermal stability are urgently desired concerning the practical application.New compositions of LiNbO_(3) modified Pb(Ni_(1/3)Nb_(2/3))O_(3)single bondPbZrO_(3)single bondPbTiO_(3) ceramics have been prepared in this study.The effects of the introduction of the LiNbO_(3) on the system were comprehensively investigated in terms of the phase structure,microstructure,electric properties,and thermal stability behavior of the ceramics.All compositions are located in the morphotropic phase boundary(MPB)region,and the ratio of the rhombohedral(R)phase increases obviously with the increase of LiNbO_(3) concentration.With increasing the LiNbO_(3) content,the piezoelectric properties were significantly enhanced.The sample added with 2%(in mole)LiNbO_(3) shows excellent electric properties,including T_(m)=185℃,εr=5,643,k_(p)=0.626,Q_(m)=51,d_(33)=902 pC/N.More importantly,no thermal depolarization behavior was observed in the temperature range of 25–100℃.For PNN-PZT-x%LN ceramics,which is mainly attributed to the pinning effect resulted by the(Li_(Pb)-Nb_(Zr/Ti)) defect dipoles.

A Symmetric-Actuating Linear Piezoceramic Ultrasonic Motor Capable of Producing a Scissoring Effect

Conventionally,to produce a linear motion,one motor’s stator is employed to drive one runner moving forward or backward.So far,there is almost no report of one electromechanical motor or piezoelectric ultrasonic motor that can directly generate two symmetrical linear motions,while this function is desired for precise scissoring and grasping in the minimally invasive surgery field.Herein,we report a brandnew symmetric-actuating linear piezoceramic ultrasonic motor capable of generating symmetrical linear motions of two outputs directly without additional mechanical transmission mechanisms.The key component of the motor is an(2×3)arrayed piezoceramic bar stator operating in the coupled resonant mode of the first longitudinal(L_(1))and third bending(B_(3))modes,leading to symmetric elliptical vibration trajectories at its two ends.A pair of microsurgical scissors is used as the end-effector,demonstrating a very promising future for high-precision microsurgical operations.

A Multilayered Magnetoelectric Transmitter with Suppressed Nonlinearity for Portable VLF Communication

Acoustically actuated magnetoelectric(ME)antenna based on the efficient oscillation of magnetic dipoles has recently been considered as a promising solution for portable very-low-frequency communications.However,the severe nonlinear dynamic behavior in the case of strong-field excitation results in insufficient radiation capability and poor communication performance for a conventional ME antenna.In this work,we propose to suppress the nonlinearity of an ME antenna by neutralizing the spring-hardening effect in amorphous Metglas and the spring-softening effect in piezoelectric ceramics through an ME multilayered transmitter(ME-MLTx)design.With a driving voltage of 50 V_(pp)at the resonance frequency of 21.2 kHz,a magnetic flux density as high as 108 fT at a distance of 100 m is produced from a single ME-MLTx.In addition,ME-MLTx performs a decreased mechanical quality factor(Q_(m))less than 40.65,and,thus,a broadened bandwidth of 500 Hz is generated.Finally,a communication link transmitting binary American Standard Code for Information Interchange-coded message is built,which allows for an error-free communication with a distance of 18 m and a data rate of 300 bit/s in the presence of heavy environment noise.The communication distance can be further estimated over 100 m when using a femtotesla-class-inductive magnetic field receiver.The obtained results are believed to bring ME antennas one step closer to being applicable in very-low-frequency communications.

A differential magnetoelectric laminated composite for vibration noise suppression

A magnetoelectric(ME) laminated composite made of one pair of piezoelectric Pb(Zr,Ti)O3(PZT) fiber layers with multiple push–pull polarization units laminated between high-permeability metglas ribbon layers with a differential configuration was proposed for vibration noise suppression. Unlike conventional metglas/PZT fiber/metglas three-layer ME laminated structures, the differential configuration has the capability to reject vibration-induced noise from the magnetic signal. The experiment results showed that the differential ME laminated composite was with up to 30 times enhancement in signal-to-noise ratio.

A square-framed ME composite with inherent multiple resonant peaks for broadband magnetoelectric response

Since the last two decades,magnetoelectric(ME)materials have been attracting considerable interest due to the potential applications,particularly in terms of magnetic field sensors,multimode energy harvesters,microelectromechanical systems,tunable microwave devices,tunable bandpass/bandstop filters,tunable phase shifters and spintronics,etc.[1,2].ME effect

A Piezoelectric and Electromagnetic Dual Mechanism Multimodal Linear Actuator for Generating Macro- and Nanomotion

Fast actuation with nanoprecision over a large range has been a challenge in advanced intelligent manufacturing like lithography mask aligner.Traditional stacked stage method works effectively only in a local,limited range,and vibration coupling is also challenging.Here,we design a dual mechanism multimodal linear actuator(DMMLA)consisted of piezoelectric and electromagnetic costator and coslider for producing macro-,micro-,and nanomotion,respectively.A DMMLA prototype is fabricated,and each working mode is validated separately,confirming its fast motion(0~50 mm/s)in macromotion mode,micromotion(0~135μm/s)and nanomotion(minimum step:0~2 nm)in piezoelectric step and servomotion modes.The proposed dual mechanism design and multimodal motion method pave the way for next generation high-precision actuator development.

REVIEW ON PIEZOELECTRIC,ULTRASONIC,AND MAGNETOELECTRIC ACTUATORS

Piezoelectric actuators operating in piezoelectric-induced strain/stress or electromechanical res.onanceinduced vibration or wave-motion friction drive mechanism have shown many advantagesover traditional electromagnetic mot ors,especilly,when miniaturizing into millimeter-scale size,while magnetoelectric act uators operating in magnetostrictive mechanism are capable of piezo-dlectric self-sensing and remote operation under an applied magnetic field.This paper summarizesthe recent progresses in piezoelectric ceramic and single crystal materials based actuators andmicromotors,ferromagnetic/ferroeletric laminated magnetoelectric actuat ors,including rotary,linear,planner,and spherical motion actuators,and bending motion magnetoelectric actuators.Their driving mechanisms,operation propertics,and applications are also explained.

Review on high temperature piezoelectric ceramics and actuators based on BiScO_(3)–PbTiO_(3) solid solutions

In recent years,industries in the fields of petrochemical,automotive,and aerospace have expressed their interest in utilizing piezoelectric actuators for high-temperature(HT)operations at the temperature above 150℃.HT piezoelectric ceramics(1x)BiScO_(3-x)PbTiO_(3)(BS-PT)are considered as one of the most competitive piezoelectric actuation materials used in the harsh environment because of its high Curie temperature(T_(C)=450℃)as well as high piezoelectric coefficient(d_(33)=460 pC/N)in the MPB composition.This paper summarized the recent progress in HT piezoelectric ceramics and actuators based on BS-PT solid solutions.The properties of BS-PT piezoelectric ceramics and actuators,including driving mechanisms,actuation performances and their applications in HT environment were also discussed.

Monolithic piezoceramic actuators with a twist

Designing artificial structures with heterogeneous elements and manipulating their interface coupling ways usually bring in synthetic neo-nature to functional devices.For piezoceramic devices,the deformation response refers to a variety of extensional,contractional,or shear modes of crystals,and also relies on boundary conditions from morphology design.However,to pursue fundamental torsion actuation in an integrated piezoceramic component is still a long-term tough task due to nil twist mode limited by microscopic crystal mirror symmetry.Herein,we demonstrate a design of cofired monolithic actuators to originally overcome this obstacle.The prototype device is composed of two sets of stacked actuation subunits that work on artificially reverse face shear modes,and their chiral stiffness couplings will synergistically contribute to synthetic twist outputs at a broad bandwidth.Finite element simulation reveals twist displacements are highly tunable by manipulating the geometrical dimensions.Transverse deflection measurements manifest the stable and sizeable linear actuation response to applied electric fields(around 3.7μm under 40 V at 1 Hz).Importantly,the design actually introduces a more general route to enable arbitrary modes and actuation states in integrated piezoceramic components.

Selenium-catalyzed oxidative carbonylation of 1,2,3-thiadiazol-5-amine with amines to 1,2,3-thiadiazol-5-ylureas

A facile one-pot, economical approach to 1,2,3-thiadiazol-5-ylureas was developed via seleniumcatalyzed oxidative carbonylation of 1,2,3-thiadiazol-5-amine with a series of amines in one-pot manner in the presence of CO and O_2. This approach is featured with cheap and easily available raw materials,cheap and reusable catalyst selenium, one-pot procedure, high atomic economy, simple operations and no emission of corrosive wastes.

Unconventional piezoelectric coefficients in perovskite piezoelectric ceramics

Piezoelectric ceramics exhibit three conventional piezoelectric coefficients,i.e.,d33,d31,d15,due to their∞mm crystal symmetry.Unconventional piezoelectric coefficients,such as d11,d12,d13,d14,d16,etc.,can only be extracted from piezoelectric single crystals of special symmetry with specific cut direction.Here we demonstrate a rotated poling method to realize unconventional piezoelectric coefficients in perovskite piezoelectric ceramics.This method is elaborated in theory and experimentally proven to be effective.Full nonzero piezoelectric coefficients in the 36 piezoelectric coefficients matrix can be obtained by combining these“quasi(effective)piezoelectric coefficients”with the conventional piezoelectric coefficients,which would expand applications in a wide variety of piezoelectric devices.