scholarly journals A Novel Approach to a Piezoelectric Sensing Element

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
M. Martinez ◽  
A. Artemev
Keyword(s):  
Thin Plate ◽  
Piezoelectric Materials ◽  
Piezoelectric Element ◽  
Electrical Signal ◽  
Sensing Element ◽  
Plate Structures ◽  
Sensing Applications ◽  
Novel Approach ◽  
Voltage Signal ◽  
Piezoelectric Structures

Piezoelectric materials have commonly been used in pressure and stress sensors; however, many designs consist of thin plate structures that produce small voltage signals when they are compressed or extended under a pressure field. This study used finite element methods to design a novel piezoelectric pressure sensor with a C-shaped piezoelectric element and determine if the voltage signal obtained during hydrostatic pressure application was enhanced compared to a standard thin plate piezoelectric element. The results of this study demonstrated how small deformations of this C-shaped sensor produced a large electrical signal output. It was also shown that the location of the electrodes for this sensor needs to be carefully chosen and that the electric potential distribution varies depending on the poling of the piezoelectric element. This study indicated that the utilization of piezoelectric materials of different shapes and geometries embedded in a polymer matrix for sensing applications has several advantages over thin plate solid piezoelectric structures.

scholarly journals A Novel Cobalt Metallopolymer with Redox-Matched Conjugated Organic Backbone via Electropolymerization of a Readily Available N4 Cobalt Complex

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1667
Author(s):  
Mikhail Karushev
Keyword(s):  
Redox Reactions ◽  
Repeat Unit ◽  
Cobalt Complex ◽  
Radical Cations ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Practical Applications ◽  
Sensing Applications ◽  
Novel Approach ◽  
Redox Switching

Fast and reversible cobalt-centered redox reactions in metallopolymers are the key to using these materials in energy storage, electrocatalytic, and sensing applications. Metal-centered electrochemical activity can be enhanced via redox matching of the conjugated organic backbone and cobalt centers. In this study, we present a novel approach to redox matching via modification of the cobalt coordination site: a conductive electrochemically active polymer was electro-synthesized from [Co(Amben)] complex (Amben = N,N′-bis(o-aminobenzylidene)ethylenediamine) for the first time. The poly-[Co(Amben)] films were investigated by cyclic voltammetry, electrochemical quartz crystal microbalance (EQCM), in situ UV‑vis-NIR spectroelectrochemistry, and in situ conductance measurements between −0.9 and 1.3 V vs. Ag/Ag+. The polymer displayed multistep redox processes involving reversible transfer of the total of 1.25 electrons per repeat unit. The findings indicate consecutive formation of three redox states during reversible electrochemical oxidation of the polymer film, which were identified as benzidine radical cations, Co(III) ions, and benzidine di-cations. The Co(II)/Co(III) redox switching is retained in the thick polymer films because it occurs at potentials of high polymer conductivity due to the optimum redox matching of the Co(II)/Co(III) redox pair with the organic conjugated backbone. It makes poly-[Co(Amben)] suitable for various practical applications based on cobalt-mediated redox reactions.

scholarly journals Piezoelectric Materials for Energy Harvesting and Sensing Applications: Roadmap for Future Smart Materials

2021 ◽  
pp. 2100864
Author(s):  
Susmriti Das Mahapatra ◽  
Preetam Chandan Mohapatra ◽  
Adrianus Indrat Aria ◽  
Graham Christie ◽  
Yogendra Kumar Mishra ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Smart Materials ◽  
Piezoelectric Materials ◽  
Sensing Applications

Contouring Medial Surface of Thin-Plate Structures Using Local Marching Cubes

2005 ◽  
Vol 5 (2) ◽  
pp. 111-115 ◽  
Author(s):  
Tomoyuki Fujimori ◽  
Hiromasa Suzuki ◽  
Yohei Kobayashi ◽  
Kiwamu Kase
Keyword(s):  
Thin Plate ◽  
Computer Aided Design ◽  
Prototype System ◽  
Marching Cubes ◽  
Plate Structures ◽  
Medial Surface ◽  
Surface Models ◽  
Marching Cubes Algorithm ◽  
Computer Aided ◽  
Ct Data

This paper describes a new algorithm for contouring a medial surface from CT (computed tomography) data of a thin-plate structure. Thin-plate structures are common in mechanical structures, such as car body shells. When designing thin-plate structures in CAD (computer-aided design) and CAE (computer-aided engineering) systems, their shapes are usually represented as surface models associated with their thickness values. In this research, we are aiming at extracting medial surface models of thin-plate structures from their CT data for use in CAD and CAE systems. Commonly used isosurfacing methods, such as marching cubes, are not applicable to contour the medial surface. Therefore, we first extract medial cells (cubes comprising eight neighboring voxels) from the CT data using a skeletonization method to apply the marching cubes algorithm for extracting the medial surface. It is not, however, guaranteed that the marching cubes algorithm can contour those medial cells (in short, not “marching cubeable”). In this study, therefore we developed cell operations that correct topological connectivity to guarantee such marching cubeability. We then use this method to assign virtual signs to the voxels to apply the marching cubes algorithm to generate triangular meshes of a medial surface and map the thicknesses of thin-plate structures to the triangle meshes as textures. A prototype system was developed to verify some experimental results.

scholarly journals Static Force Measurement Using Piezoelectric Sensors

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Kyungrim Kim ◽  
Jinwook Kim ◽  
Xiaoning Jiang ◽  
Taeyang Kim
Keyword(s):  
Surface Charge ◽  
Piezoelectric Effect ◽  
Force Measurement ◽  
Piezoelectric Materials ◽  
Force Sensor ◽  
Piezoelectric Sensors ◽  
Force Sensing ◽  
Static Force ◽  
Sensing Applications ◽  
Direct Piezoelectric Effect

In force measurement applications, a piezoelectric force sensor is one of the most popular sensors due to its advantages of low cost, linear response, and high sensitivity. Piezoelectric sensors effectively convert dynamic forces to electrical signals by the direct piezoelectric effect, but their use has been limited in measuring static forces due to the easily neutralized surface charge. To overcome this shortcoming, several static (either pure static or quasistatic) force sensing techniques using piezoelectric materials have been developed utilizing several unique parameters rather than just the surface charge produced by an applied force. The parameters for static force measurement include the resonance frequency, electrical impedance, decay time constant, and capacitance. In this review, we discuss the detailed mechanism of these piezoelectric-type, static force sensing methods that use more than the direct piezoelectric effect. We also highlight the challenges and potentials of each method for static force sensing applications.

Minimization of the Vibration Energy of Thin-Plate Structures

1992 ◽  
Author(s):  
Katsumi Inoue ◽  
Dennis P. Townsend ◽  
John J. Coy
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Thin Plate ◽  
Optimization Method ◽  
Optimum Shape ◽  
Vibration Energy ◽  
Plate Structures ◽  
Constant Weight ◽  
Exciting Frequency ◽  
The Given

Abstract An optimization method is proposed to reduce the vibration of thin-plate structures. The method is based on a finite-element shell analysis, a modal analysis, and a structural optimization method. In the finite-element analysis, a triangular shell element with 18 degrees of freedom is used. In the optimization, the overall vibration energy of the structure is adopted as the objective function, and it is minimized at the given exciting frequency by varying the thickness of the elements. The technique of modal analysis is used to derive the sensitivity of the vibration energy with respect to the design variables. The sensitivity is represented by the sensitivities of both eigenvalues and eigenvectors. The optimum value is computed by the gradient projection method and a unidimensional search procedure under the constraint condition of constant weight. A computer code, based on the proposed method, is developed and is applied to design problems using a beam and a plate as test cases. It is confirmed that the vibration energy is reduced at the given exciting frequency. For the beam excited by a frequency slightly less than the fundamental natural frequency, the optimized shape is close to the beam of uniform strength. For the plate, the optimum shape is obtained such that the changes in thickness have the effect of adding a stiffener or a mass.

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