Abstract: CeO2 ceramics with ZnO additions (1 and 2 wt%) were prepared with conventional solid-state
route have been investigated. Doping with ZnO (up to 1 wt%) can effectively promote the densification of
CeO2 ceramics at low sintering temperature. At 1550 oC, CeO2 ceramics with 1 wt% ZnO addition
possesses a dielectric constant ( ε
r) of 23.2, a Q×f value of 53000 GHz and a temperature coefficient of
resonant frequency (τf) of –47 ppm/oC.
Abstract: The cordierite powders have been synthesized by low temperature combustion technique using
urea as fuel, nitrates as oxidizer and silicic acid as silica source. The sintering behavior and crystallization
process were investigated. The results showed that the powders could be sintered at a temperature lower
than 1000 °C. The μ-cordierite crystallized from glass at first, and then transformed into α-cordierite at
higher temperature. The obtained cordierite based glass ceramics at different temperatures have low
dielectric constant (4.16 ~ 5.02 at 1 MHz) and low dielectric dissipation factor (≈ 0.003 at 1 MHz) as well
as low temperature sintering behavior, which is compatible for electronic packaging.
Abstract: Automatic measurement system with multimode for microwave ceramic materials is
developed. Based on traditional parallel-plate resonance method, the whole system is composed of a
parallel-plate cavity, a vector network analyzer (VNA), an interface card for GPIB to USB, and a PC with
measurement programs. Besides the fundamental mode, higher order resonant modes are also measured
at the same time. Based on a platform of VEE, a set of analysis software is programmed with the functions
of not only automatically calibrating and searching resonant frequencies but also automatically
computing and displaying the dielectric parameters of microwave materials with high reliability and
efficiency in a wide frequency range.
Abstract: The wireless passive surface acoustic wave (SAW) impedance-loaded sensors offer new and
exciting perspectives for remote monitoring and controlling of moving parts, even in harsh environments.
However, the classical simulation models such as equivalent circuit model (ECM) and coupling of modes
(COM) model are not rigorous enough for these sensors since these sensors usually work in the RF band.
We try to make it more accurate by using FEM/BEM (combined finite element method and boundary
element method) model to determine some key parameters used in the COM model of impedance-loaded
SAW sensors. In this paper, we use periodic Green function which is the basis of FEM/BEM model to
determine the key parameters. The result of measurements on real SAW is nearly in accordance with that
Abstract: A micro piezoelectric motor with a disk-pivot structure is presented. Different from conventional
wobble-type piezoelectric motor using piezoelectric rod or cylinder, piezoelectric disc is used to
excite wobble modes and metal cylinder stator is used to amplify the transverse displacement, metal rod
rotor is actuated to rotate. The outer diameter of the actuator is 14mm. In this paper, the performances of
the motor are characterized, where a high rotation speed and a high toque are obtained. The property of
start-up period movement of the motor was studied by a high-speed camera. The toque of the motor was
calculated by the property of the start-up movement.
Abstract: New holding mechanism is proposed to improve the positioning capability of ultrasonic linear
motor based on previous researches proposed by the authors. Through the previous holding mechanism
using a resonance system, the remarkable operating stability and controllability at high-power driving
were achieved. However, when higher power is demanded, big noise in supporting parts of a resonance
system is generated and these parts could be damaged and worn due to the discordance of a resonance
frequency between a transducer and supporting horns. Also the coupling problem of two vibration modes
remains because of using a half wavelength. This research proposes a new design of ultrasonic motor with
three supporting points in one vibrator for high stiffness support and discusses the solution about the
coupling effect and the nano-level positioning capability. Finally, a maximum driving mechanical force
and the positioning accuracy were achieved over 75 N and 100 nm through this mechanism. Moreover,
the efficiency of motor was 35% when the trust force was 52 N and the velocity was 0.27 m/s.
Abstract: A novel rotary piezoelectric micro-motor (φ8mm×10mm) is proposed in this paper. Different
from the conventional traveling wave ultrasonic motor using piezoelectric ceramic ring, four multilayer
co-firing piezoelectric ceramic bulks (2mm×2mm×3mm) are used to generate vibration in the ring type
stator. The layout and electric signals applied to the piezoelectric ceramic bulks are designed for the
purpose of generating elliptical trajectories on the surface of the stator. The working mode of the
prototype motor is simulated by the finite element method, and also measured by the Doppler Laser
Vibrometer. The experimental results are in good agreement with simulation, which verifies the
effectiveness of the finite element model. The prototype motor is driven at the low voltage of 12V under
the frequency of 64.91 KHz.
Abstract: In this paper, we suggested the new standards of motor design in using of Soft magnetic
composite (SMC) material. Previous motor design in using of SMC material executed the same
procedures of silicon steel. These procedures assumed that all places of material have the same density
distribution and B-H curves. But we showed that the SMC material has inequality density distribution. By
using powder forming analysis with FEM analysis, we showed that difference of density distribution
could not be avoided because of the shear stress on powder, surface of the mold and punch. Therefore the
magnetic characteristic was not the same in all places of material. So, we suggested the new method of
motor design which considered the inequality density distribution in using of SMC material. And we
compared previous method results and new method results and showed the differences of the result
values. The density deviation of the SMC motor core was 5.8% and efficiency deviation was 3%.
Especially the output value was different above 11% when we got the results by using previous method.
Abstract: This paper presents a valve-less micropump which is actuated by a piezoelectric ceramic chip.
We employ a microelectromechanical system process for the silicon substrate and anodic bonding for
assembly of the Pyrex glass and silicon wafer. The reciprocating type micropump contains two
nozzle/diffuser elements and a silicon membrane with an embedded piezoelectric ceramic actuator.
Abstract: A novel model of 3-DOF multilayer PZT micromanipulator is promoted and simulated with
finite element analysis method. States under different applied voltages were discussed, including the
motion along axis Z and the rotation along axis X and the bisector between X-Y. After analyzing the
distribution of stress, we propose some method, which helps to improve the performance of the
micromanipulator. We also do some quantificational analysis about the micromanipulator, discovering
that the relationship between the displacements of the probe and applied voltages is almost perfectly
linear. By comparing the constant D defining the relationship of the displacements of probe tip and
applied voltages, the simulation is proved to be correct. Comparing the performance between the
single-layer and multi-layer PZT, it shows that the multi-layer PZT can reduce input voltages, whereas
can produce the same displacement. Ceramic sample is prepared for further experiment.