A novel piezoelectric energy harvester equipped with two piezoelectric beams and two cylinders was proposed in this work. The energy harvester can convert the kinetic energy of water into electrical energy by means of vortex-induced vibration (VIV) and wake-induced vibration (WIV). The effects of load resistance, water velocity and cylinder diameter on the performance of the harvester were inve...

We integrated a piezoelectric sensing layer lamina containing liquid crystals (LC) and spiropyran (SP) in a LC/SP mixture to create an optically reconfigurable modal sensor for a cantilever beam. The impedance of this LC/SP lamina was decreased by UV irradiation which constituted the underlying mechanism to modulate the voltage externally applied to the piezoelectric actuating layer. Illuminati...

Current controlled piezoelectric beams have been very popular recently due to the substantial reduction of hysteresis between the input and output. Even though there are many different PDE models for the voltage and charge controlled piezoelectric beams, there is no thoroughly derived PDE model in the literature for current controlled piezoelectric beams. A variational approach is utilized to d...

Piezoelectric optical scanner is developed for multi-coordinate control of optical laser beam. Such type of optomicro-mechanical systems can be used for accurate angular or linear deflection of optical elements in various optomechanical and optoelectronic systems. The operating principle of these devices is based on piezoelectric effect and on conversion of high-frequency multi-dimensional mech...

Title of dissertation: PIEZOELECTRIC MICROBEAM RESONATORS BASED ON EPITAXIAL Al0.3Ga0.7As FILMS Lihua Li, Doctor of Philosophy, 2005 Dissertation directed by: Professor Don DeVoe Department of Mechanical Engineering In this work, piezoelectric resonators based on single crystal Al0.3Ga0.7As films are implemented. The combination of Si doped Al0.3Ga0.7As as electrode layers and moderate piezoele...

We have expressed in E. coli a series of periodic polypeptides represented by sequence 1. Our objective has been an understanding of the role of chemical sequence in determining the chain folding behavior of periodic macromolecules. Molecular organization has been examined by infrared spectroscopy and IH and l 3 ~ NMR methods and a preliminary model of the folded structure has been developed.

This paper presents the high order frequency-amplitude relationship for nonlinear transversely vibrating beams with odd and even nonlinearities, using Homotopy Perturbation Method with an auxiliary term (HPMAT). The governing equations of vibrating buckled beam, beam carrying an intermediate lumped mass, and quintic nonlinear beam are investigated to exhibit the reliability and ability of the p...

We investigate the physics of an optically driven micromotor of biological origin. When a single, live red blood cell (RBC) is placed in an optical trap, the normal biconcave disc shape of the cell is observed to fold into a rod-like shape. If the trapping laser beam is circularly polarized, the folded RBC rotates. A model based on geometric considerations, using the concept of buckling instabi...

With demand for the long-term continued use of existing building facilities, structural health monitoring and damage detection are attracting interest from society. Sensors various types have been practically applied in industry to satisfy this need. Among sensors, piezoelectric sensors an extremely promising technology by virtue their cost advantages durability. Although they used aerospace ci...

Energy harvesting from vibration for low-power electronics has been investigated intensively in recent years, but rotational energy harvesting is less investigated and still has some challenges. In this paper, a methodology for low-speed rotational energy harvesting using piezoelectric transduction and frequency up-conversion is analysed. The system consists of a piezoelectric cantilever beamwi...