High aspect ratio plasma etching of bulk lead zirconate titanate

This paper reports on the controlled manipulation of high aspect ratio ferroelectric microtubes on pre-patterned templates by dielectrophoresis. Microtubes of ferroelectric lead zirconate titanate (PZT, a chemical formula of Pb(Zr0.52Ti0.48 )O3) with an outer diameter of 2 ?m, a length of about 30 ?m and a wall thickness of 400 nm were prepared by vacuum infiltration method using macroporous silicon templates. To position and align tubes at designed places, an alternating electric field was applied to a colloidal suspension of PZT tubes through lithographically defined microelectrodes. This would enable creation of a stable electrical connection to individual tubes for making a testing structure for rapid electrical characterization. Electric-field assisted assembly experiments demonstrated that the frequency and magnitude of the applied electric field control dielectrophoretic long-range forces, and hence spatial movement of the tubes in a non-uniform electric field. The most efficient biasing for the assembly of tubes across the electrode gap of 12 ?m was a square wave signal of 5 Vrms and 10 Hz. By varying the applied frequency in between 1 and 10 Hz, an enhancement in tube alignment was observed due to possible changes in dielectrophoretic torque. The results indicate a great potential for utilizing dielectrophoresis in construction of more complex, hierarchical 3-D device structures using the PZT 1-D like tubes as the building units.

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Fluid Manipulation by Bio-Mimetic Cilia

Volume 2: Biomedical and Biotechnology Engineering ◽

10.1115/imece2007-42376 ◽

2007 ◽

Author(s):

Kieseok Oh ◽

Jae-Hyun Chung ◽

Santosh Devasia ◽

James J. Riley

Keyword(s):

Aspect Ratio ◽

Lead Zirconate Titanate ◽

High Aspect Ratio ◽

Small Volume ◽

Lead Zirconate ◽

Maximum Displacement ◽

Assembly Method ◽

Fluidic Device ◽

Structure Assembly ◽

Fluid Manipulation

This paper describes the fabrication and actuation of bio-mimetic cilia for fluid manipulation. High aspect ratio cilia made of polydimethylsiloxane (PDMS) were successfully assembled in a microfluidic device by our novel fabrication method. This method was to release the PDMS cilia from a Si mold and assemble the cilia in a device. All the process was performed under water in order to avoid the stiction and pairing of the PDMS cilia. The underwater assembly method enabled a high aspect ratio PDMS structure assembly in a fluidic device. The PDMS cilia were actuated in air and water by lead-zirconate-titanate (PZT) microstage. In the fabricated device, the maximum displacement of the cilia was observed at 120Hz in air and at 50Hz in de-ionized (DI) water with our experimental condition. The actuated cilia in a solution produced convective and propulsive fluid flow near the cilia structure. The developed device can be used for precise handling of small volume sample (e.g., 1 μL).

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Influence of aspect ratio on effective electromechanical coupling of nanocomposites with lead zirconate titanate nanowire inclusion

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x11416025 ◽

2011 ◽

Vol 22 (16) ◽

pp. 1879-1886 ◽

Cited By ~ 14

Author(s):

Clark Andrews ◽

Yirong Lin ◽

Haixiong Tang ◽

Henry A. Sodano

Keyword(s):

Aspect Ratio ◽

Mechanical Loading ◽

Polymer Matrix ◽

Lead Zirconate Titanate ◽

Coupling Coefficient ◽

High Aspect Ratio ◽

Electromechanical Coupling ◽

Lead Zirconate ◽

Electromechanical Coupling Coefficient ◽

Curved Surfaces

Piezoelectric ceramics offer exceptional sensing and actuation properties, however, they are prone to breakage and are difficult to apply to curved surfaces in their monolithic form. One method to alleviate these issues is through the use of 0–3 active composites, which are formed by embedding piezoelectric particles into a polymer matrix that protects the ceramic from breaking under mechanical loading. This class of material offers certain advantages over monolithic materials; however, they have seen little use due to the low electromechanical coupling offered by these materials. Here, we demonstrate that by controlling the aspect ratio of the filler, the electromechanical coupling coefficient can be significantly improved. For all volume fractions tested, nanocomposites with high aspect ratio lead nanowires filler had higher coupling with increases as large as 2.3 times. Furthermore, the nanocomposite’s coupling was more than 50% of the piezoceramic fillers’ when nanowires were used.

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Micro-Robotic Actuation Units Based on Thin-Film Piezoelectric and High-Aspect Ratio Polymer Structures

Volume 4: 19th Design for Manufacturing and the Life Cycle Conference; 8th International Conference on Micro- and Nanosystems ◽

10.1115/detc2014-35145 ◽

2014 ◽

Cited By ~ 1

Author(s):

Minchul Shin ◽

Jongsoo Choi ◽

Ryan Q. Rudy ◽

Christopher Kao ◽

Jeffrey S. Pulskamp ◽

...

Keyword(s):

Thin Film ◽

Aspect Ratio ◽

Lead Zirconate Titanate ◽

High Aspect Ratio ◽

Low Voltage ◽

Weight Bearing ◽

Lead Zirconate ◽

Dynamic Responses ◽

Low Voltage Operation ◽

Fabrication Procedure

A fabrication procedure is presented for creating microactuation elements that link piezoelectric thin-films with high-aspect ratio parylene microstructures. Resulting actuators permit relatively large rotational motions for low voltage operation, while maintaining large weight-bearing capacity. Actuator fabrication is performed on a silicon wafer though a combination of metal and thin-film lead-zirconate-titanate (PZT) deposition and patterning, parylene refill of high-aspect ratio trenches, and dry release of moving parts from the silicon substrate. Static and dynamic responses of various test structures are measured, to estimate material properties of the integrated PZT-polymer structures, for use in future actuator modeling and optimization.

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Effects of Aspect Ratio of Lead Zirconate Titanate on 1-3 Piezoelectric Composite Properties

Japanese Journal of Applied Physics ◽

10.1143/jjap.36.6062 ◽

1997 ◽

Vol 36 (Part 1, No. 9B) ◽

pp. 6062-6064 ◽

Cited By ~ 9

Author(s):

Yoshihiro Hirata ◽

Toshiyuki Numazawa ◽

Hiroshi Takada

Keyword(s):

Aspect Ratio ◽

Lead Zirconate Titanate ◽

Lead Zirconate ◽

Piezoelectric Composite ◽

Zirconate Titanate ◽

Composite Properties

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Convergent-bceam diffraction studies on lead zirconate titanate Ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143961 ◽

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.

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