Direct tensile mechanical loading of an individual single-crystal BaTiO(3) nanowire was realized to reveal the direct piezoelectric effect in the nanowire. Periodic voltage generation from the nanowire was produced by a periodically varying tensile mechanical strain applied with a precision mechanical testing stage. The measured voltage generation from the nanowire was found to be directly prop...

A novel antenna beam-steering technology is proposed for emerging millimeter-wave (mm-wave), broadband mobile technologies such as 5G and beyond. high-gain (23 dBi) with 30° beam steering designed tested at around the 38 GHz band. Fabry–Perot type leaky-wave (LWA) employed main radiating structure, a tunable high-impedance surface (HIS) used ground plane. The HIS phase tuning accomplished by el...

In this article, the first 237 GHz traveling wave tube (TWT) is presented as a high-power amplifier for terahertz (THz) cloud radar. As common with previous G-band tubes developed at Beijing Vacuum Electronics Research Institute, employs 20 kV, 50 mA pencil electron beam focused using periodic permanent magnets (PPMs) to achieve compactness. A folded waveguide (FWG) slow-wave structure (SWS) mo...

The paper reviews the recent applications of piezoelectric materials in structural health monitoring and repair conducted by the authors. First, commonly used piezoelectric materials in structural health monitoring and structure repair are introduced. The analysis of plain piezoelectric sensors and actuators and interdigital transducer and their applications in beam, plate and pipe structures f...

Wave propagation in composite structures with shunted piezoelectric patches is investigated in this work. The Wave Finite Element(WFE) approach is firstly developed as a prediction tool for wave propagation characteristics like dispersion curves in composite structures, and subsequently extended to consider shunted piezoelectric elements through the Diffusion Matrix Model(DMM). A three-layered ...

In this paper, controlling the location of the tip of an L-shape beam under gravity field is investigated. The beam is covered with piezoelectric patches. The gravity filed moves the tip of beam downward and the actuators with induced voltage move the tip to the previous location. to optimize the best location and voltages for actuators, the particle swarm optimization algorithm code is develop...

An efficient semi-numerical framework is used in this paper to analyze the dynamic model of an axially moving beam with a nonlinear attachment composed energy sink and piezoelectric device. The governing equations motion system are derived by using Hamilton’s principle von Karman strain-displacement relation Euler - Bernoulli theory. modeled as lumped mass point mass, spring cubic stiffness lin...

Bent and folded beam configurations have been popularly used in electrothermoelastic (E-T) actuation. This paper introduces new designs of thermal end-effector with micro-grasping and micro-heating capabilities. We obtained analytical models for all possible steady state temperature responses of suspended and overhanging microstructures that constitute bent beam, folded beam, and combined actua...

This paper investigates the use of capacitive proximity sensors as sources of contact-free feedback signal measurement for active vibration attenuation applications. An experimental laboratory device is introduced, which consists of a clamped cantilever beam and actuated by bonded piezoelectric actuators. A measurement model is created and experimentally verified for the assessment of beam tip ...

Piezoelectric actuation is widely used for the active vibration control of smart structural systems, and corresponding research has largely focused on linear electromechanical devices. This paper investigates the design and analysis of a novel piezoelectric actuator that uses a piezoelectric cantilever beam with a loading spring to produce displacement outputs. This device has a special nonline...