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Gosain R.,Pennsylvania State University | Gurdal E.A.,Pennsylvania State University | Zhuang Y.,Pennsylvania State University | Park S.-H.,Micromechatronics Inc. | And 2 more authors.
Japanese Journal of Applied Physics | Year: 2010

This paper treats an innovative piezoelectric pump based on one of the piezoelectric actuators, the "cymbal". We describe the design, fabrication process, pumping principle and performance analysis of a miniaturized, ultrasonic, valve less pump. The cymbal actuator has been shown to have larger displacement and generative force than the bimorph actuators. The key is much higher underwater pressure induced by the cymbal in comparison with the bimorph. We used a double-layered cymbal with the advantage that it can behave both, as an "in-phase" extensional or an "out-of- phase" bending actuator. Our setup promises a hassle-free, internal system which offers considerably smaller size and weight, thereby facilitating the current trend of size reduction in the electronics industry. In addition, ease of fabrication make this device an attractive candidate for large scale production/industrial use. Taking inspiration from current and past trends we tried to balance the trade-off between efficient performance and device size. Therefore, a key feature of this pump is performance with respect to size (volume less than 1.5 cm3). The pump was able to generate a maximum back pressure greater than 5.3 kPa and an approximate maximum flow rate of 10ml/min. © 2010 The Japan Society of Applied Physics. Source

Horsley E.L.,University of Sheffield | Carazo A.V.,Micromechatronics Inc. | Nguyen-Quang N.,Ho Chi Minh City University of Technology | Foster M.P.,University of Sheffield | Stone D.A.,University of Sheffield
IEEE Transactions on Power Electronics | Year: 2012

The inductorless piezoelectric transformer (PT)-based resonant converter topology allows all the components between the half-bridge inverter and rectifier in a conventional LCC converter to be replaced with a single ceramic component. This offers potential savings in cost, size, and mass. However, zero-voltage switching (ZVS) becomes more difficult to achieve because the MOSFET output capacitances are augmented by the PT input capacitance. This paper presents an analytical model for the ZVS condition in inductorless PT-based converters. Unlike previously reported models, the proposed model is shown to offer a level of accuracy comparable to a SPICE simulation and to correlate well with experimental results. Using a normalization scheme and numerical optimization techniques, the criteria for achieving inductorless ZVS are found in terms of the equivalent circuit components. Both ac-output and dc-output variants are considered, and design charts for ensuring ZVS in five different topologies are presented. The results and design charts are applicable to any type of PT that can be represented by the standard PT equivalent circuit. © 2006 IEEE. Source

Agency: Department of Defense | Branch: Air Force | Program: STTR | Phase: Phase I | Award Amount: 99.29K | Year: 2009

The objective of this proposal is to demonstrate the feasibility of producing a Conformal Actuator Array Active Skin (CAAAS) that can be implanted on the surface of the airfoil to deliver a system that can actively control transition and separation. It will be realized through operation of actuators with unique driving methods as well as recent advances and innovations in piezoelectric actuator technology, i.e. large displacement and blocking force. The actuator thickness will be below 2 mm so it can be distributed on the surface of the airfoil in the form of 2 dimensional arrays. The array will be covered by compliant outer membrane (active skin) to provide conformal actuation. The actuator will be excited by various driving frequencies, displacement, and waveforms to obtain required airflow controllability. Especially, waveform manipulation will induce effects analogous to conventional suctioning and blowing without making holes (conformal actuation). In addition, the array will generate traveling wave both in the transverse and streamwise directions to reduce shear stress and control airflow effectively. The combinatory effects of controlling each actuator and the array will be analyzed and optimized thus producing desired airflow.

Micromechatronics Inc. | Date: 2007-03-06

Piezoelectric devices for producing and/or making use of vibratory, oscillatory, reciprocatory, bending, linear, or rotary movement for use with valves, solenoids, relays, switches, motors, generators, chargers, transformers, pumps, compressors, gyroscopes, gimbals, printers, odometers, speedometers, robotic limbs, intra-vascular drills, optical apparatuses, bending actuators, linear actuators, rotational actuators, and sensors for displacement, velocity, pressure, stress, temperature, and acceleration; electronic drive circuits for such piezoelectric devices; computer software for modeling such piezoelectric devices; electromechanical transducers incorporating a piezoelectric component for use as sensors, actuators, and positioners.

Dong S.,Virginia Polytechnic Institute and State University | Dong S.,Peking University | Carazo A.V.,Micromechatronics Inc. | Park S.H.,Micromechatronics Inc.
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control | Year: 2011

A multilayer laminated piezoelectric Pb(Zr 1. xTi x)O 3 (PZT) ceramic transformer, operating in a halfwavelength longitudinal resonant mode (λ/2 mode), has been analyzed. This piezoelectric transformer is composed of one thickness-polarized section (T-section) for exciting the longitudinal mechanical vibrations, two longitudinally polarized sections (L-section) for generating high-voltage output, and two insulating layers laminated between the T-section and L-section layers to provide insulation between the input and output sections. Based on the piezoelectric constitutive and motion equations, an electro-elasto-electric (EEE) equivalent circuit has been developed, and correspondingly, an effective EEE coupling coefficient was proposed for optimum design of this multilayer transformer. Commercial finite element analysis software is used to determine the validity of the developed equivalent circuit. Finally, a prototype sample was manufactured and experimental data was collected to verify the model's validity. © 2011 IEEE. Source

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