Piezoelectric ceramic pressure transducer in the shape of a spherical segment

Turning cutting tool with large length–diameter ratio has been essential when machining structural part with deep cavity and in-depth hole features. However, chatter vibration is apt to occur with the increase of tool overhang. A slender turning cutting tool with a length–diameter ratio of 7 is developed by using a vibration absorber equipped with piezoelectric ceramic. The vibration absorber has dual functions of vibration transfer to the absorber mass and vibration conversion to the electrical energy via the piezoelectric effect. Equations of motion are established considering the dual damping from the piezoelectric ceramic and rubber gasket. The equivalent damping of piezoelectric ceramic is derived, and the geometries are optimized to achieve optimal vibration suppression. The modal analysis demonstrates that the cutting tool with the vibration absorber can reach 80.1% magnitude reduction. Machining tests are carried out in the end. The machining acceleration and machined surface roughness validate the vibration suppression of the VA, and the output voltage by the piezoelectric ceramic demonstrates the ability of vibration sensing.

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Power-Generation Optimization Based on Piezoelectric Ceramic Deformation for Energy Harvesting Application with Renewable Energy

Energies ◽

10.3390/en14082171 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2171

Author(s):

Hyeonsu Han ◽

Junghyuk Ko

Keyword(s):

Power Generation ◽

Renewable Energy ◽

Energy Harvesting ◽

Piezoelectric Material ◽

Lead Zirconate Titanate ◽

Piezoelectric Ceramic ◽

Piezoelectric Element ◽

Piezoelectric Ceramics ◽

Lead Zirconate ◽

Piezoelectric Energy

Along with the increase in renewable energy, research on energy harvesting combined with piezoelectric energy is being conducted. However, it is difficult to predict the power generation of combined harvesting because there is no data on the power generation by a single piezoelectric material. Before predicting the corresponding power generation and efficiency, it is necessary to quantify the power generation by a single piezoelectric material alone. In this study, the generated power is measured based on three parameters (size of the piezoelectric ceramic, depth of compression, and speed of compression) that contribute to the deformation of a single PZT (Lead zirconate titanate)-based piezoelectric element. The generated power was analyzed by comparing with the corresponding parameters. The analysis results are as follows: (i) considering the difference between the size of the piezoelectric ceramic and the generated power, 20 mm was the most efficient piezoelectric ceramic size, (ii) considering the case of piezoelectric ceramics sized 14 mm, the generated power continued to increase with the increase in the compression depth of the piezoelectric ceramic, and (iii) For piezoelectric ceramics of all diameters, the longer the depth of deformation, the shorter the frequency, and depending on the depth of deformation, there is a specific frequency at which the charging power is maximum. Based on the findings of this study, PZT-based elements can be applied to cases that receive indirect force, including vibration energy and wave energy. In addition, the power generation of a PZT-based element can be predicted, and efficient conditions can be set for maximum power generation.

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Goldmann Tonometry and Corneal Biomechanics

Applied Sciences ◽

10.3390/app11094025 ◽

2021 ◽

Vol 11 (9) ◽

pp. 4025

Author(s):

Dario Messenio ◽

Marco Ferroni ◽

Federica Boschetti

Keyword(s):

Mechanical Properties ◽

Anterior Chamber ◽

Pressure Transducer ◽

Pearson Correlation ◽

Corneal Thickness ◽

Applanation Tonometry ◽

In Vitro Tests ◽

Goldmann Tonometry ◽

The Difference

Glaucoma is the second cause of irreversible blindness in the world. Intraocular pressure (IOP) is a recognized major risk factor for the development and progression of glaucomatous damage. Goldmann applanation tonometry (GAT) is internationally accepted as the gold standard for the measurement of IOP. The purpose of this study was to search for correlations between Goldmann tonometry and corneal mechanical properties and thickness by means of in vitro tests. IOP was measured by the Goldmann applanation tonometer (GIOP), and by a pressure transducer inserted in the anterior chamber of the eye (TIOP), at increasing pressure levels by addition of saline solution in the anterior chamber of enucleated pig eyes (n = 49). Mechanical properties were also determined by inflation tests. The GAT underestimated the real measurements made by the pressure transducer, with most common differences in the range 15–28 mmHg. The difference between the two instruments, highlighted by the Bland–Altman test, was confirmed by ANOVA, normality tests, and Mann–Whitney’s tests, both on the data arranged for infusions and for the data organized by pressure ranges. Pearson correlation tests revealed a negative correlation between (TIOP-GIOP) and both corneal stiffness and corneal thickness. In conclusion, data obtained showed a discrepancy between GIOP and TIOP more evident for softer and thinner corneas, that is very important for glaucoma detection.

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Influence of machining parameters on micro-motion platform displacement during grinding Al-Mg alloys workpiece assisted by two-dimensional low-frequency vibration

Composites and Advanced Materials ◽

10.1177/2633366x20985308 ◽

2021 ◽

Vol 30 ◽

pp. 2633366X2098530

Author(s):

Shiyang Yu ◽

Shijun Ji ◽

Ji Zhao ◽

Chao Zhang ◽

Handa Dai

Keyword(s):

Cutting Force ◽

Piezoelectric Ceramic ◽

Input Voltage ◽

Orthogonal Test ◽

Spindle Speed ◽

Test Method ◽

Influential Factor ◽

Machining Parameters ◽

Motion Platform ◽

Micro Motion

The main factors affecting the displacement of micro-motion platform during the grinding process are spindle speed, cutting force, and piezoelectric ceramic input voltage model. This article, using the orthogonal test method, found a set of machining parameters which lead to less displacement deviation between practical test and theoretic analysis. First of all, single-factor experiments were carried out to study how spindle speed, cutting force, and piezoelectric ceramic input voltage model affect the experimental results, and then the orthogonal test was conducted. The experimental datum shows that voltage model was the most influential factor, followed by spindle speed and cutting force. The optimum combination of grinding parameters was obtained as spindle speed of 800 r/min, cutting force of 18 N, and voltage model radius of 12 µm. At this time, the average unit error of displacement of micro-motion platform was 9.13%.

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Bar piezoelectric ceramic transformers

IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control ◽

10.1109/tuffc.2013.2720 ◽

2013 ◽

Vol 60 (7) ◽

pp. 1479-1486 ◽

Cited By ~ 3

Author(s):

Jiri Erhart ◽

Petr Pulpan ◽

Lubos Rusin

Keyword(s):

Piezoelectric Ceramic

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