scholarly journals Mechanical Fatigue Resistance of Piezoelectric PVDF Polymers

Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 503 ◽  
Author(s):  
Youn-Hwan Shin ◽  
Inki Jung ◽  
Hyunchul Park ◽  
Jung Pyeon ◽  
Jeong Son ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Remnant Polarization ◽  
Output Voltage ◽  
Piezoelectric Response ◽  
Phase Content ◽  
Metal Electrodes ◽  
Mechanical Fatigue ◽  
Tension And Compression ◽  
Response To Stress ◽  
Tension Experiments

The fatigue resistance of piezoelectric PVDF has been under question in recent years. While some report that a significant degradation occurs after 106 cycles of repeated voltage input, others report that the reported degradation originates from the degraded metal electrodes instead of the piezoelectric PVDF itself. Here, we report the piezoelectric response and remnant polarization of PVDF during 107 cycles of repeated compression and tension, with silver paste-based electrodes to eliminate any electrode effect. After applying repeated tension and compression of 1.8% for 107 times, we do not observe any notable decrease in the output voltage generated by PVDF layers. The results from tension experiments show stable remnant polarization of 5.5 μC/cm2, however, the remnant polarization measured after repeated compression exhibits a 7% decrease as opposed to the tensed PVDF. These results suggest a possible anisotropic response to stress direction. The phase analyses by Raman spectroscopy reveals no significant change in the phase content, demonstrating the fatigue resistance of PVDF.

Electromechanical Coupling of PZT Nanofibers

2008 ◽  
Author(s):  
Shiyou Xu ◽  
Yong Shi
Keyword(s):  
Forced Vibration ◽  
Output Voltage ◽  
Electromechanical Coupling ◽  
Mechanical Strain ◽  
Electrospinning Process ◽  
Piezoelectric Response ◽  
Vibration Source ◽  
Titanium Film ◽  
Three Point Bending ◽  
Vibration Tests

This paper presented the results of electromechanical characterization of PZT nanofibers through applied mechanical strain and forced vibration. PZT nanofibers were fabricated by electrospinning process. Titanium film with ZrO2 layer was used to collect the nanofibers and also used as the substrates of the test coupons for the bending tests. Mechanical strain was applied to the test coupons through three-point-bending using Dynamic Mechanical Analyzer (DMA). The largest output voltage was 170mV under 0.5% applied strain. Silicon substrate with trenches was also used to collect the PZT nanofibers for the forced vibration tests. The output voltage from 150Hz sinusoid vibration source was also measured. The peaks of the output voltage were 64.9mV and −95.9mV, respectively. These tests have demonstrated the piezoelectric response of PZT nanofibers. Further tests are to be conducted to precisely determine the piezoelectric constants of PZT nanofibers.

Improving mechanical fatigue resistance by optimizing the nanoporous structure of inkjet-printed Ag electrodes for flexible devices

2014 ◽  
Vol 25 (12) ◽  
pp. 125706 ◽  
Author(s):  
Byoung-Joon Kim ◽  
Thomas Haas ◽  
Andreas Friederich ◽  
Ji-Hoon Lee ◽  
Dae-Hyun Nam ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Nanoporous Structure ◽  
Flexible Devices ◽  
Mechanical Fatigue ◽  
Ag Electrodes

scholarly journals Mechanical fatigue resistance of an implantable branched lead system for a distributed set of longitudinal intrafascicular electrodes

2017 ◽  
Vol 14 (6) ◽  
pp. 066014 ◽  
Author(s):  
A E Pena ◽  
S S Kuntaegowdanahalli ◽  
J J Abbas ◽  
J Patrick ◽  
K W Horch ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Lead System ◽  
Mechanical Fatigue ◽  
Intrafascicular Electrodes

High piezoelectric response and excellent fatigue resistance in Rb-substituted BNT–BKT–BT ceramics

2020 ◽  
Vol 55 (18) ◽  
pp. 7634-7644
Author(s):  
Xuefan Zhou ◽  
Xi Yuan ◽  
Zhongna Yan ◽  
Guoliang Xue ◽  
Hang Luo ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Piezoelectric Response

scholarly journals The effect of N-acetylcysteine on mechanical fatigue resistance of antibiotic-loaded bone cement

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Erhan Sukur ◽  
Abdulhalim Akar ◽  
Huseyin Nevzat Topcu ◽  
Ozgur Cicekli ◽  
Alauddin Kochai ◽  
...  
Keyword(s):  
Bone Cement ◽  
Fatigue Resistance ◽  
Mechanical Fatigue

Aerodynamic and Acoustic Voice Measures Before and After an Acute Public Speaking Stressor

2020 ◽  
Vol 63 (10) ◽  
pp. 3311-3325
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer
Keyword(s):  
Fundamental Frequency ◽  
Salivary Cortisol ◽  
Public Speaking ◽  
Stress System ◽  
Before And After ◽  
Subglottal Pressure ◽  
Response To Stress ◽  
System Activation ◽  
Speaking Fundamental Frequency ◽  
Pituitary Adrenal Axis

Purpose The goal of this study was to determine if differences in stress system activation lead to changes in speaking fundamental frequency, average oral airflow, and estimated subglottal pressure before and after an acute, psychosocial stressor. Method Eighteen vocally healthy adult females experienced the Trier Social Stress Test (TSST) to activate the hypothalamic–pituitary–adrenal axis. The TSST includes public speaking and performing mental arithmetic in front of an audience. At seven time points, three before the stressor and four after the stressor, the participants produced /pa/ repetitions, read the Rainbow Passage, and provided a saliva sample. Measures included (a) salivary cortisol level, (b) oral airflow, (c) estimated subglottal pressure, and (d) speaking fundamental frequency from the second sentence of the Rainbow Passage. Results Ten of the 18 participants experienced a hypothalamic–pituitary–adrenal axis response to stress as indicated by a 2.5-nmol/L increase in salivary cortisol from before the TSST to after the TSST. Those who experienced a response to stress had a significantly higher speaking fundamental frequency before and immediately after the stressor than later after the stressor. No other variable varied significantly due to the stressor. Conclusions This study suggests that the idiosyncratic and inconsistent voice changes reported in the literature may be explained by differences in stress system activation. In addition, laryngeal aerodynamic measures appear resilient to changes due to acute stress. Further work is needed to examine the influence of other stress systems and if these findings hold for dysphonic individuals.

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