scholarly journals Novel thick-film piezoceramic micro-generator based on free-standing structures

2008 ◽  
Author(s):  
N.M. White ◽  
N.R. Harris ◽  
Swee Leong Kok ◽  
M.J. Tudor
Keyword(s):  
Thick Film ◽  
Free Standing

scholarly journals Free-standing thick-film piezoelectric device

2008 ◽  
Vol 44 (4) ◽  
pp. 280 ◽  
Author(s):  
S.L. Kok ◽  
N.M. White ◽  
N.R. Harris
Keyword(s):  
Thick Film ◽  
Free Standing ◽  
Piezoelectric Device

Single-domain Yba2Cu3Oy thick films and fabrics prepared by an infiltration and growth process

2001 ◽  
Vol 16 (4) ◽  
pp. 955-966 ◽  
Author(s):  
E. Sudhakar Reddy ◽  
J. G. Noudem ◽  
M. Tarka ◽  
G. J. Schmitz
Keyword(s):  
Liquid Phase ◽  
Thick Film ◽  
Growth Process ◽  
Thick Films ◽  
Solidification Process ◽  
Film Coating ◽  
Single Domain ◽  
Free Standing ◽  
Liquid Phases ◽  
Woven Structure

An infiltration and growth process has been developed to produce single-domain Yba2Cu3Oy(123) as thick films on various substrates or as self-supporting fabrics. Commercially available Y2O3 cloths of square woven or satin woven structure were infiltrated with liquid phases from a suitable source containing barium cuprates and copper oxides and subsequently converted into Y2BaCuO5(211) and −123 phases by a series of distinct peritectic reactions. Depending on the final form of 123, the Y2O3 cloth was either clamped firmly at corners to produce a self-supporting 123 fabric or placed on a suitable substrate to result in a thick film coating of 123. The source material for the liquid phase being in the form of solid blocks was placed at corners of the cloth in the case of free-standing 123 fabrics. In case of the thick film configuration the liquid phase powder was spread on the surface of the Y2O3 cloth. A small c-axis-oriented MgO or Nd(123) seed was used to generate an oriented 123 domain in the infiltrated fabric. The solidification process was optimized to transform the entire Y2O3 fabric into a single-domain 123. The microstructure of the single domain was optimized in terms of 211 size and content for high Jc. A detailed description of the process, the growth mechanism, the resulting microstructures was given, and basic superconducting properties of the new form of 123 are briefly discussed.

scholarly journals Fully Integrated Bridge-Type Anemometer in LTCC-Based Microfluidic Systems

2008 ◽  
Vol 54 ◽  
pp. 401-404 ◽  
Author(s):  
Heike Bartsch de Torres ◽  
Christian Rensch ◽  
Torsten Thelemann ◽  
J. Müller ◽  
M. Hoffmann
Keyword(s):  
Thick Film ◽  
Cost Effective ◽  
Free Standing ◽  
Fully Integrated ◽  
Integrated Electronics ◽  
Wide Range ◽  
Bridge Type ◽  
Process Gases ◽  
The Cost

A thick film anemometer for in situ control of the flow rate in fluidic systems was designed, manufactured and characterized. The sensor is integrated in a retention modulus consisting of Low Temperature Cofired Ceramics (LTCC). These materials allow the cost-effective realisation of fluidic microsystems with integrated electronics. The challenge of the work is to design an anemometer under the exclusive use of thick film technologies. The necessity to trim resistors causes the external use of relevant pastes. Therefore, the use inside of a closed fluidic system requires the leak of process gases and, at the same time, a maximal heat-insulating of the sensor element from the substrate. Free-standing elements necessitate the control of stress due to shrinking mismatch, TCE mismatch, density gradients and deformation during the lamination. In the presented solution, embossed flue channels prevent blow forming on a free-standing bridge. The anemometer has a linear sensor characteristic for flow rates up to 0.1 ml/min. The layout guarantees that the fluid gets only in contact with the basic ceramic material, which is compatible with a wide range of biological substances. Therefore the sensor is applicable in contact with cell fluids or PCRreagents.

Investigation of Using Free-Standing Thick-Film Piezoelectric Energy Harvesters to Develop Wideband Devices

2014 ◽  
Vol 14 (08) ◽  
pp. 1440016 ◽  
Author(s):  
Yang Bai ◽  
Carl Meggs ◽  
Tim W. Button
Keyword(s):  
Thick Film ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Single Frequency ◽  
Free Standing ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Wide Range ◽  
Resistive Loads ◽  
The Individual

This paper is concerned with the wideband behavior of single-frequency and multi-frequency free-standing thick-film piezoelectric energy harvesters. The energy harvesting devices have been fabricated and brief fabrication information is provided. The individual harvesters have been combined with either symmetric or asymmetric tip masses, with some being connected together to form a harvester array. Testing has been undertaken using harmonic vibrations with a wide range of frequencies and accelerations, and also using a random machinery vibration, and data have been recorded in terms of un-rectified and rectified open-circuit voltage, output power with matched resistive loads, peak-to-peak tip displacement, and even charging rates of capacitors. As a general result, the individual harvesters with asymmetric tip masses have vibrated nonlinearly below and in the vicinity of the resonant frequencies. An individual harvester vibrating at the resonant frequency with 0.5 g acceleration has been able to charge a 1000 μF capacitor to 1 V within 12 min and to 1.5 V within 30 min. Also, the harvester array has exhibited a wideband response, where an open-circuit voltage of above 0.8 V has been provided within a certain range of frequencies. Finally, the harvester array has successfully charged a capacitor on a vibrating test sieve shaker, proving the feasibility of the proposed device in real applications.

Screen-Printed Ceramic Based MEMS Piezoelectric Cantilever for Harvesting Energy

2014 ◽  
Vol 90 ◽  
pp. 84-92 ◽  
Author(s):  
Swee Leong Kok ◽  
Abdul Rani Othman ◽  
Azizah Shaaban
Keyword(s):  
Thick Film ◽  
Ambient Vibration ◽  
Free Standing ◽  
Charge Generation ◽  
Lower Electrode ◽  
Electrode Layer ◽  
Additional Layer ◽  
Piezoelectric Cantilever ◽  
Screen Printing Technology ◽  
Resultant Stress

Screen-printing technology provides a convenient method in fabricating thick-film conductive circuits and devices in the past few decades. Conventionally, piezoelectric thick-film is printed on alumina substrate with high mechanical Q-factor and resonates at higher frequency outside the range of ambient vibration. As the piezoelectric charge generation is proportional to the mechanical stress on the material, therefore the substrate can be removed in order to lower the natural frequency of the structure. In this paper, a series of piezoelectric ceramic cantilevers were fabricated in the form of free-standing cantilever. An additional layer of ceramic was also introduced to the upper and lower electrode to prevent delamination. The issue of zero resultant stress for the sandwiched piezoelectric cantilever was solved by repeating the electrode-PZT-electrode layer to form a multilayer structure. It was found from the experiment that an electrical output power of 32 μW was generated when it operates at its resonant frequency at 403 Hz.

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