A Study on Long-Term In Vitro Reliability of Intracochlear Lead-Zirconate-Titanate Microactuators

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Yifeng Liu ◽  
Chuan Luo ◽  
G. Z. Cao ◽  
Clifford R. Hume ◽  
I. Y. Shen
Keyword(s):  
Lead Zirconate Titanate ◽  
Electrical Breakdown ◽  
Failure Mechanisms ◽  
Electrode Array ◽  
Lead Zirconate ◽  
Acoustic Stimulation ◽  
Structural Failure ◽  
Significant Drop ◽  
Zirconate Titanate

An intracochlear lead-zirconate-titanate (PZT) microactuator integrated with a cochlear implant electrode array could be a feasible strategy to implement combined electric and acoustic stimulation inside the cochlea. The purpose of this paper is to characterize in vitro a prototype PZT microactuator for intracochlear applications, including service life, failure mechanisms, and lead leaching. PZT microactuators were driven sinusoidally to failure in air and in artificial perilymph. Frequency response functions (FRFs) and electrical impedance were monitored. After the PZT microactuators failed, the amount of leached lead was measured via inductive coupled plasma mass spectrometry (ICP-MS). Two failure mechanisms are identified: electrical breakdown and structural failure. The electrical breakdown, possibly from loss of parylene encapsulation, is evidenced by a sudden and significant drop of the actuators' electrical resistance. The structural failure, possibly from electrode delamination, is evidenced by a sudden and significant drop of FRFs. The amount of lead leached from the PZT microactuator is well below published safety guidelines from federal agencies.

Assessment of human bones encompassing physiological decay and damage using piezo sensors in non-bonded configuration

2017 ◽  
Vol 28 (14) ◽  
pp. 1977-1992 ◽  
Author(s):  
Shashank Srivastava ◽  
Suresh Bhalla ◽  
Alok Madan
Keyword(s):  
Lead Zirconate Titanate ◽  
Mechanical Impedance ◽  
Lead Zirconate ◽  
Biomedical Sensors ◽  
Human Bones ◽  
Zirconate Titanate ◽  
Artificial Bones ◽  
Sensor Configuration

In the recent years, several biomedical applications of lead zirconate titanate piezo-electric ceramic patches based on the electro-mechanical impedance technique have been reported in the literature. However, practical application of the technique on live subjects is severely hampered due to the requirement of bonding the patch with bone or cartilage with an adhesive. In addition, live subjects have skin cover over the bone. This article proposes and evaluates the feasibility of employing lead zirconate titanate patches as biomedical sensors in non-bonded configuration for assessing the physiological conditions of bones. For this purpose, a special design is proposed where the lead zirconate titanate patch is first bonded on a thin aluminum strip, which is in turn clamped securely on the biomedical subject. The proposed configuration is investigated both in vitro and in vivo. The non-bonded piezo sensors are first investigated to identify dynamic parameters of the bone through lab-based experimental study involving artificial bones. Thereafter, physiological damage and decay conditions are artificially simulated in the experimental bones and the same are correlated with changes in conductance signatures from the non-bonded piezo sensor as well as the lead zirconate titanate patch in the conventional adhesively bonded (direct bonding to the subject) configuration. The trend of the conductance signatures in the healthy and the damaged conditions from the non-bonded piezo sensor is found to correlate well with the corresponding signatures from the directly bonded piezo sensor. At the same time, the repeatability of the signatures is also found to be satisfactory. After success in bare bones, the non-bonded piezo sensor configuration is extended to monitor the condition of bones covered with skin and tissue, simulated in the lab with the aid of silicone-based coating. Finally, a proof-of-concept experiment on a live human subject is successfully demonstrated. The overall results of the study demonstrate very good prospects of employing lead zirconate titanate patches in non-bonded piezo sensor mode for monitoring the condition of human bones and other related biomedical subjects.

Convergent-bceam diffraction studies on lead zirconate titanate Ceramics

1986 ◽  
Vol 44 ◽  
pp. 482-483
Author(s):  
M.L.A. Dass ◽  
T.A. Bielicki ◽  
G. Thomas ◽  
T. Yamamoto ◽  
K. Okazaki
Keyword(s):  
Lead Zirconate Titanate ◽  
Direct Proof ◽  
Lead Zirconate ◽  
Subsolidus Phase ◽  
Pzt Ceramics ◽  
Subsolidus Phase Diagram ◽  
Zirconate Titanate ◽  
Two Phases ◽  
Cbd Method ◽  
Titanate Ceramics

Lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), ceramics are ferroelectrics formed as solid solutions between ferroelectric PbTiO3 and ant iferroelectric PbZrO3. The subsolidus phase diagram is shown in figure 1. PZT transforms between the Ti-rich tetragonal (T) and the Zr-rich rhombohedral (R) phases at a composition which is nearly independent of temperature. This phenomenon is called morphotropism, and the boundary between the two phases is known as the morphotropic phase boundary (MPB). The excellent piezoelectric and dielectric properties occurring at this composition are believed to.be due to the coexistence of T and R phases, which results in easy poling (i.e. orientation of individual grain polarizations in the direction of an applied electric field). However, there is little direct proof of the coexistence of the two phases at the MPB, possibly because of the difficulty of distinguishing between them. In this investigation a CBD method was found which would successfully differentiate between the phases, and this was applied to confirm the coexistence of the two phases.

Fabrication of Bimorph Lead Zirconate Titanate Thick Films on Metal Substrates Via the Cold Sintering Process

2020 ◽  
Author(s):  
Dixiong Wang ◽  
Sinan Dursun ◽  
Lisheng Gao ◽  
Carl S. Morandi ◽  
Clive A. Randall ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Thick Films ◽  
Lead Zirconate ◽  
Sintering Process ◽  
Metal Substrates ◽  
Zirconate Titanate

New synthesis route for lead zirconate titanate powder

2016 ◽  
Vol 42 (6) ◽  
pp. 6782-6790 ◽  
Author(s):  
Linggen Kong ◽  
Inna Karatchevtseva ◽  
Rohan Holmes ◽  
Joel Davis ◽  
Yingjie Zhang ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
Synthesis Route ◽  
Zirconate Titanate ◽  
New Synthesis

scholarly journals Publisher's Note: “Epitaxial lead zirconate titanate on gallium nitride” [J. Appl. Phys. 113, 074107 (2013)]

2013 ◽  
Vol 114 (23) ◽  
pp. 239901
Author(s):  
E. A. Paisley ◽  
H. S. Craft ◽  
M. D. Losego ◽  
H. Lu ◽  
A. Gruverman ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
Zirconate Titanate
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