Development of 2-2 piezoelectric ceramic/polymer composites by direct-write technique

Abstract

The Micropen™ direct-write technique was used to fabricate ceramic skeletal structures to develop piezoelectric ceramic/polymer composites with 2-2 connectivity for medical imaging applications. A lead zirconate titanate PZT paste with ∼35 vol.% solids loading was prepared as a writing material and the paste's rheological properties were characterized to evaluate its feasibly for Micropen deposition. A serpentine pattern was designed and deposited in AutoCAD and with a 100 μm pen tip, respectively. After debinding and sintering, the microstructural analysis showed that the ceramic structures were fully densified, with good bonding among layers. Typical single-layer thickness was ∼50 μm, and sintered line width was ∼120 μm. The composites containing 30-45 vol.% PZT were fabricated within 1 cm 2 area, with thicknesses ranging from 350 to 380 μm. Their electromechanical and dielectric properties were measured and found similar to that of composites fabricated by other techniques. The k t was ∼0.61, d 33 was 210-320, with Q m of ∼6 and dielectric constant of 650-940.

3D printing of piezoelectric element for energy focusing and ultrasonic sensing

“…During the past thirty years, direct inkjet based printing,extrusion-based direct-write technique, and light exposure based Stereolithography Apparatus (SLA) have been used in ceramic component fabrication. [13][14][15][16][17][18][19][20][21][22][23] Many efforts have been made on applying SLA in ceramics component fabrication, due to its advantages in fabricating complex geometry and high resolution (X-Y resolution<25μm). Usually, the AM process of fabricating ceramic components involves two main steps: (1) green-part fabrication to define part geometry; and (2) debinding and sintering of green-parts to achieve dense components.…”

Fine‐Scaled Piezoelectric Ceramic/Polymer 2‐2 Composites for High‐Frequency Transducer

“…The d 33 was demonstrated to be a multiple dependence value and the two composites had d 33 between 29.8% and 32.3% of the bulk ceramic. For composite B, though the d 33 was slightly lower, the free dielectric constant K T decreased to 324 and the g 33 increased to 62 × 10 −3 Vm/N, which was higher than that of bulk ceramic and those usually reported, indicating that the composites were good receivers of ultrasonic waves . Low tan δ, although slightly higher than that of the bulk ceramic, were obtained in composites and is beneficial for avoiding massive heat generation in transducer operations .…”

“…Meanwhile, for acquiring a moderate acoustic impedance, high PZT volume fractions should be avoided, which requires a careful selection of PZT element width and kerf spacing. To date, several solid freeform fabrication techniques such as fused deposition of ceramics, robocasting, and direct‐ink writing were developed for fabricating PZT/polymer 2‐2 composites . The most outstanding advantages of these techniques are the designing flexibility and accuracy for novel and complex shapes.…”

Ceramic fabrication using Mask-Image-Projection-based Stereolithography integrated with tape-casting

“…[4]) uses a nozzle system to extrude and deposit ceramic slurries or pastes. After the green part is built by the extrusion and deposition process, the built structure is debinded and sintered in a furnace.…”