TitleMicropen direct-write technique for fabrication of advanced electroceramic and optical materials
NameSun, Jingjing (author), Safari, Ahmad (chair), Klein, Lisa (internal member), Danforth, Stephen (internal member), Vittadello, Michele (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectMaterials Science and Engineering,
DescriptionDirect-write technologies, a subset of the rapid prototyping, have been applied for many applications including electronics, photonics and biomedical engineering. Among them, MicropenTM is a promising technique, providing precision deposition of materials with various viscosities, on-line design changes and writing on nonplanar substrates. The objective of this project was to directly write two- and three-dimensional novel structures by MicropenTM for potential optical and transducer applications.
First, to gain a basic understanding of MicropenTM operation, poly(methyl methacrylate) (PMMA) solutions were developed as a model system. The effects of solution rheological properties on deposition conditions were investigated. Secondly, PMMA/SiO2 hybrids were developed using sol-gel process. The effects of organic/inorganic ratios on thermal stability, microstructure and optical properties were studied. The solution with 80 wt% PMMA loading was chosen to deposit lines for optical applications.
Another application was the direct-write of lead zirconate titanate (PZT) thick films (6-70 µm) for MEMS or high frequency medical imaging applications. Pastes consisting of 15-30 vol% ceramic loading in a sol-gel solution were prepared for the deposition of films on various substrates. The PZT sol was used as a binder as well as to achieve low temperature heat treatment of the films. Using the 15 vol% paste with a 250-µm pen tip, a four-layer film was deposited on a silicon substrate. This 16-µm film with 1 cm2 area had K of 870, tanδ of 4.1%, Pr of 12.2 µC/cm2 and Ec of 27 kV/cm.
Furthermore, MicropenTM was utilized for the direct-write of ceramic skeletal structures to develop PZT ceramic/polymer composites with 2-2 connectivity for medical ultrasound transducers. Ceramic/binder based pastes were developed as writing materials. The 35 vol% paste exhibited shear thinning with a viscosity of 45 Pa•s at lower shear rate and 3 Pa•s at higher shear rate. Using a 100-µm pen tip, the fabricated composite with ~360 µm height had resonance frequencies of ~4 MHz, and electromechanical properties of K=650, tanδ=2.1%, kt=0.60 and d33=210 pC/N. Finally, composites with linear and Gaussian volume fraction gradients were fabricated by MicropenTM. Their vibration amplitude profiles showed maximum output at center with gradual decreasing towards edge of the composites.
NoteIncludes bibliographical references (p. 173-184)
Noteby Jingjing Sun
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.