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- Front Matter: Volume 6836
- MOEM I
- MOEM II
- Microfluidics
- Fabrication
- RF MEMS
- Sensor
- Sensor and Actuator
- Poster Session
Front Matter: Volume 6836
Front Matter: Volume 6836
Show abstract
This PDF file contains the front matter associated with SPIE
Proceedings Volume 6836, including the Title Page, Copyright
information, Table of Contents, Introduction, and the
Conference Committee listing.
MOEM I
A review of different types of photonic MEMS tunable lasers
A. Q. Liu,
H. Cai,
X. M. Zhang,
et al.
Show abstract
In this paper, four different types of miniaturized Microelectromechanical Systems (MEMS) based tunable lasers, from
photonic MEMS laser designs to fabrication techniques, are introduced. These tunable lasers are MEMS external cavity
laser, injection-locked laser, coupled-cavity laser, and dual-wavelength laser. The properties, functionalities and
performances of the MEMS-based tunable lasers are individually discussed based on their experimental results. The
potential applications in fiber optical communications are also identified. These tunable lasers, which are more
innovative in terms of design, specifications and configurations compared to traditional lasers, also provide significant
improvements in their functionalities.
Development of a 1x2 piezoelectric optical fiber switch
Show abstract
This paper presents the design, fabrication and performance of a 1×2 piezoelectric optical switch. The optical switch is
developed based on the concept that the input fiber is directly moved by the deflection of a piezoelectric tube actuator.
The piezoelectric tube actuator used in this switch is manufactured through an electrophoretic deposition process. The
tube is inexpensive to produce and compact in size with high mechanical performance. It has a maximum deflection of
30μm which is capable to actuate the input fiber for switching. The multimode fiber optical switch has been successfully
assembled. To reduce the misalignment loss between the fibers, the output fibers are precisely aligned in silicon vgrooves.
Different components are bonded with low shrinkage adhesive in order to minimize their position inaccuracy.
The performance characteristics of the optical switch have been measured, with an insertion loss of 1dB, crosstalk of -45dB and switching speed from 5 to 10ms. The switch also shows good reliability and requires small driving power. The
development of multimode optical switch prototypes proves that the idea of piezoelectric switching is feasible. Further
developments include the improvement of switching performance, reduction of the prototype size and the fabrication of
multiple output prototypes.
An active interconnecting mechanism for free-space optic applications
Show abstract
In this paper, a new method for interconnecting free-space
micro-optoelectromechanical system (MOEMS) devices is
developed. The heterogeneous design and assembly concept is demonstrated by a pair of V-shape actuators and related
assembly mechanism, fabricated on a silicon-on-insulator (SOI) wafer. A two-channel free-space DWDM filter has
been assembled and characterized. The results show low insertion losses. The device architecture allows hybrid optical
system integration on a single platform. The assembled optical devices can be made of different materials, on different
substrates and/or with incompatible fabrication techniques. The integration platform provides potentials for realizing a
micro optical bench with equivalent optical performance that currently require bulk optics setups.
Experimental study on roughness and flatness of micromirror fabricated by different anisotropic silicon etching processes
Show abstract
Fabrication of flat, free-standing silicon diaphragms as micromirrors using etching processes is the key in the
development of optical Micro-Elecro-Mechanical System(MEMS) devices, such as tunable F-P(Fabry-Perot) filters. It is
very important for etching process to get smooth surface and uniform depth because they greatly affect the performance
of the final device. In this paper, we report the experimental results about roughness and flatness of silicon micromirror
fabricated by wet and dry etching processes. The investigated process involved wet-etching process in self-prepared
KOH solution, and dry etching process with such machines as ALCATEL 601E DRIE(Deep Reactive Ion Etching) and
STS ICP (Inductivity Coupling Plasma). It was found that wet etching process could supply more uniform etching depth,
whereas the better surface roughness was gotten by dry etching. For a 30μm target depth, surface roughness less than
3-nm and maximal depth difference less than 0.3-μm were obtained by STS ICP and KOH respectively.
MOEM II
Optical MEMS devices based on micromachined torsion structure
Yaming Wu,
Jing Xu,
Sihua Li,
et al.
Show abstract
Optical MEMS components with optical fiber inputs and outputs are the most important kinds of optical MEMS devices
because of their applications in optical communication industry and fiber-optic sensors. Efficient optical coupling is the
key to develop optical MEMS devices for optical communication and sensing, however, efficient coupling between
MEMS actuators or sensing structures and optical fibers is a challenging job. Besides high performance MEMS actuators
and coupling micro-optics are needed, the MEMS structures should adapt to coupling micro-optics. The torsion MEMS
micro-mirrors and gratings can couple with fiber collimators at low insertion loss, therefore, the torsion MEMS
structure is a good choice for optical MEMS devices, especially for continuous or multi-level controlled devices. In
this paper, we report three kinds of optical MEMS devices based on silicon torsion micro structure, MEMS variable
optical attenuator (VOA), 1×8 MEMS optical switch and high-speed MEMS torsion blazed grating , which have been
developed recently in our optical MEMS research group. The three devices are coupled with optical fibers by optical
fiber collimators, so low loss coupling can be achieved.
Manufacturing and testing of the line-array fiber optic image slicer based on silicon V-grooves
Show abstract
Linear fiber-optic image slicer is used more and more in spatial exploration and imaging system. In this paper, a plane
arranging method of fiber-optic array based on Si-V grooves is established in order to improve the accuracy and reduce
the cost of manufacturing. Firstly, the Si-V groove array is micro-machined with anisotropic etching process, then optical
fibers are placed in the grooves orderly with plane arranging method. Secondly, the end surfaces of the device are
polished, also the linear fiber-optic image slicer is packaged. Finally, some parameters are tested, including structure
parameters, transmittivity and vibration test. Experimental results indicate that the maximum error accumulated in 2000
periods of the Si-V grooves is 0.5μm, the error of the height in
Si-V grooves is less than 0.15μm, the roughness of the
end surface is less than 0.9nm. The transmittivity of the linear fiber-optic image slicer that without optical film is 51.46%
at the wavelength of 632.8nm. After random vibration experiment, the ratio of the broken fiber increased by 0.1%. While
the temperature reached 320°C, the stress of epoxy will be 130Mpa, which is close to the limit resistance stress of
139Mpa, some cracks appeared.
Proposal and investigation for a planar MOEMS 1x8 wavelength-selective switch
Show abstract
This paper presents a new wavelength-selective switch by combining silicon micromaching and microassembly
techniques. The 1×8 wavelength-selective switch (WSS) based on micro electro mechanical systems (MEMS)
technology is proposed and fabricated with micro electromagnetic actuators, reflecting prisms and narrow-band thin
films filters. And a 8×8 WXC prototype node is implemented by using 1×8 WSSs as building elements. The working
principle and the configuration of the micro electromagnetic actuator are illuminated. By analysis, the property suits for
the application when the inputs are 2V, and the best fiber-to-fiber insertion loss 5dB is gotten.
High-speed and large-scale electromagnetically actuated MEMS scanning-mirror
Show abstract
Large-scale micro-electromechanical systems (MEMS) scanning mirrors play a primary role in many fields of
manipulating light beam scanning, such as rapid optical spectrum analyzers (OSAs) based on dispersive gratings using in
near infrared (NIR) region. According to the applications, a high speed electromagnetically actuated MEMS scanning
mirror with large mirror area of 9×6mm2 has been developed. The MEMS scanning mirror chip, which is fabricated
using bulk silicon micromachining process and electroplating technique, is immersed in a constant 365 mT magnetic
field parallel to the coil plane and generates the maximum optical deflection angle of ±11.15° at the 1.39 kHz resonant
frequency. The quality factor, Q, of 77 is achieved in air corresponding to a low power consumption of 102.6 mW. In
addition, the surface roughness of less than 20nm for scanning mirror has been measured and the optical reflectivity at
the wavelength of 1550nm is high up to 87%. The results show that the device is adequate for mm-sized scanning
systems and compatible with smart OSAs applications.
Microfluidics
Large distance liquid pumping by AC electro-osmosis for the delivery of biological cells and reagents in microfluidic devices
Show abstract
Liquid pumping, mixing and biological cells/reagents delivery in micro- or nano-liter volume is critical in lab-on-chip
systems. We describe a novel AC electro-osmosis device for delivering reagents/cells over large distances without a
global pressure gradient. Our device features facile transport range scalability in x- and y-axes, using continuous flow
in a serpentine microchannel realized by microelectrode pairs arrayed in a unique antiparallel-asymmetric configuration.
Co-planar microelectrodes on glass substrate are fabricated from gold with chromium as seed layer using micro-electromechanical
system (MEMS) technology. Sealed upon the micro-electrodes is an open-ended serpentine microchannel
having width 80μm and depth 45μm; formed by micromolding PDMS with a silicon-based mold. AC signals at 3.5Vpp
and 0.5V DC offset is used to energize the microelectrodes, and polystyrene beads with diameter 5.0μm are used as
tracer particles to visualize flow. Maximum velocity of 871 μm/s was recorded using AC signals at 8 kHz. The ease
of scaling up transport distance range in 2-axes is unique to our device. Scalability in x-axis is achieved by varying the
number of microelectrode pairs; and in y-axis by varying the number of microelectrodes iterations and the
corresponding number of turns in the serpentine microchannel. Being scalable in transporting fluidic volume with high
efficiency under small driving voltages makes our device suitable for miniaturization in a micro-total-analytical-system.
Our device could be applied towards multiple point reagents, biological cells and particles delivery and mixing in a
lab-on-chip.
Rapid and simple half-quantitative measurement alpha-fetoprotein by poly(dimethylsiloxane) microfluidic chip immunochromatographic assay
Show abstract
In this article, a kind of microfluidic method based on MEMS technology combined with gold immunochromatographic
assay (GICA) is developed and discussed. Compared to the traditional GICA, this method supplies us convenient,
multi-channel, in-parallel, low cost and similar efficiency approach in the fields of alpha-fetopro-tei (AFP)detection.
Firstly, we improved the adhesion between the model material SU-8 and Silicon wafer, optimized approaches of the
fabrication of the SU-8 model systematically, and fabricate the PDMS micro fluid chip with good reproduction
successfully. Secondly, Surface modification and antibody immobilization methods with the GICA on the PDMS micro
fluid analysis chip are studied, we choose the PDMS material and transfer GICA to the PDMS micro fluid chip
successfully after researching the antibody immobilization efficiency of different materials utilized in fabrication of the
micro fluid chip. In order to improve the reaction efficiency of the immobilized antibody, we studied the characteristics
of micro fluid without the gas drive, and the fluid velocity control in our design; we also design structure of grove to
strengthen the ability of immobilizing the antibody. The stimulation of the structure shows that it achieves great
improvement and experiments prove the design is feasible.
Amperometric immunosensor using electric field to improve the interaction between antibody and antigen
Show abstract
This paper proposes a method that using an electric field to improve the immobilization of analyte in an amperometric immunosensor. The amperometric immunosensor, which has a two-microelectrode system enclosed in a SU-8 reaction microwell, has been developed with MEMS technology for the detection of the human immunoglobulin (HIgG). Electric field has been applied above the working electrode by setting the appropriate potential between two electrodes to enable more antigen "IgG" to be assembled to the sensing interface with less time. The results demonstrate that the immunochemical incubation time spent on the immobilization of HIgG has been shortened, and the property of the immunosensor has been enhanced.
Fabrication
MEMS-based uncooled infrared bolometer arrays: a review
Show abstract
Uncooled infrared bolometer arrays have become the technology of choice for low-cost infrared imaging systems used in
applications such as thermography, firefighting, driver night vision, security and surveillance. Uncooled infrared
bolometer arrays are reaching performance levels which previously only were possible with cooled infrared photon
detectors. With a continuously increasing market volume (> 100 000 units per year to date), the cost for uncooled
infrared imaging chips are decreasing accordingly. In this paper we give an overview of the historical development of
uncooled infrared bolometer technology and present the most important bolometer performance parameters. The
different technology concepts, bolometer design approaches and bolometer materials (including vanadium oxide,
amorphous silicon, silicon diodes, silicon-germanium and metals) are discussed in detail. This is followed by an analysis
of the current state-of-the-art infrared bolometer technologies, the status of the infrared industry and the latest technology
trends.
Contrastive study on the mechanical performance of MEMS microsprings fabricated by LIGA and UV-LIGA technology
Show abstract
With good mechanical performance and mature fabrication technology of LIGA and UV-LIGA, Ni is chosen as the
material of S style MEMS microspring. At 24°C and 25% relative humidity, five different points in LIGA Ni sample
were tested with the MICRO HARDNESS TESTER, and the Young's modulus was 219GPa. From the tensile tests of
UV-LIGA Ni sample the Young's modulus of UV-LIGA Ni is 180GPa. The S style microspring was fabricated by LIGA
and UV-LIGA technology separately. Applying the Castigliano second theorem of energy method in macro theory, the
spring constant formulas of S style microspring in three application modes were deduced, and the correctness was
verified by the FEA (Finite Element Analysis) simulation. The experiments of S style microspring's deformation
properties were carried out by the Tytron250 micro force test machine and a tensile measurement system separately. The
experimental results agree with the theoretical analysis. Based on the above analysis, the change laws of microspring's
spring coefficient in different application patters are summarized.
Calibration of computer vision positioning system for MEMS wire bonder
Show abstract
In this paper, a calibration method to improve the accuracy of MEMS Wire Bonder is presented. With the requirements
of high accuracy and high speed in wire bonding, vision system has become one of important factors which influence the
precision of MEMS packaging. It can be used as a feedback of control system to fulfill the requirement of accurate
locating. A positioning system using computer vision technology has been designed to obtain high locating accuracy
during wire bonding. The calibration of this system is the assurance to get distorting parameters and the relationship of
all coordinate systems. Usually, Zhang's camera calibration method is widely used to get high accurate camera
calibration results. But this method was only applied in normal imaging system. In this paper, the method is improved to
be applied in micro-imaging system used for MEMS Wire Bonder. Combining the camera pinhole model and the Gauss
lens law, the micro-imaging camera model is established. Certain smaller rotation angles are adopted to get acceptable
calibration results. Simulations and experiments are performed to validate the proposed method with satisfied results.
A micro-electromechanical system design and manufacture considering fabrication error
Show abstract
MEMS fabrication technology has very high fabrication precision, but there is still fabrication error inevitably like any
other fabrication technology. We adopt LIGA technology to fabricate a Micro Electro-Mechanical System. From the
analysis of fabrication process, the fabrication errors of MEMS part consist of mask and LIGA fabrication error. The
designed MEMS parts can be divided into metal and PMMA part. Synthesizing the mask and LIGA fabrication errors,
the errors of metal entity and cavity structure are -10.5μm~+5.5μm and -5.5μm~+10.5μm. The errors of PMMA entity and cavity structure are -5μm~+10μm and -10μm~+5μm. Analyzing each situation, the most interference dimension of the four assembling situations is 20μm. According to the conclusion, we leave 10μm margin for each of the two parts
assembling together. So the whole margin of the two parts is 20μm, which ensures that the two MEMS parts can be assembled reliably. Measuring the fabricated MEMS part with a micro precision measurement equipment indicated that the fabrication error was in the scope of theoretical analysis. The fabricated LIGA MEMS system can be assembled
reliably and the centrifugal experiment indicated that the motional part worked well and moved to the destination position.
RF MEMS
Investigation of charge accumulation in the dielectric for robust RF MEMS switches
Show abstract
For higher-power-handling RF MEMS switches, the design of the switch is based on fixed-fixed beam capacitive structure with electrostatic actuation. Such RF MEMS switches are perceived to be unreliable because of the stiction and screening of the beam caused by charge accumulation in the dielectric layer. The research effort for a robust RF MEMS solution has been made for more than a decade. In this paper the models for stiction and screening caused by charge accumulation have been reviewed. As the first part of this paper, the possible charging mechanisms will be described, such as, 1) the dielectric charging arises from charges distributed throughout the dielectric material, 2) the presence of charges at the dielectric interface. In order to avoid the charge accumulation, trapped charges in the dielectric layer have to quickly vanish. Relaxing mechanisms of short time must be created inside of the dielectric for quick charge recombination. The second part of this paper will report the recent effort to create relaxing mechanisms of short time by using, such as doping dielectric, nano-composite dielectrics, or multi-layer stack of dielectric. Actuation wave form dependence of the charge accumulation will be also presented.
New developments on polymer-based MEMS phase shifters
Show abstract
Phase shifter is one of the core components for phased-array antennas which find wide applications in satellite systems,
telecommunications, wireless systems, radar systems and tracking systems. The current high-frequency phase shifters
are mainly built upon active semiconductor technologies which suffer from high fabrication and assembly costs. In this
work, we propose a cost-effective approach to fabricate distributed MEMS transmission line phase shifters on a
polymer-glass substrate. The fabrication procedure is compatible with CMOS and post-CMOS processes. The polymerglass
phase shifter was characterized from DC to 26 GHz. The measurements show a phase shift of 120° and a 2.5-dB
insertion loss at 26 GHz.
Influence of ion implantation on dielectric charging in capacitive RF MEMS switches
Show abstract
Dielectric charging is one of the main problems leading to failure of capacitive RF MEMS switches. In this work
phosphorus or boron ions were implanted into dielectric layer by ion implantation. After dielectric layer modification by
ion implantation, we focus on investigation of the mechanisms of the charge accumulation and recombination after the
sample electrically stressed with 80 V for 30 seconds. A
Metal-Insulator-Semiconductor (MIS) capacitor structure is
used for such an investigation. Silicon nitride films as the insulator in MIS structure were deposited by LPCVD process.
The space charge accumulation in the silicon nitride film can be characterized by Capacitance-Voltage (C-V)
measurement. Because of the ionization of the gas in the operating environment of the switch, ion injection by actuation
voltage during the operation of the RF MEMS switch will play the role to enhance the charge accumulation in the
dielectric layer. Our work offers a principle to understand the effect of the operating environment to the lifetime and
reliability of the RF capacitive MEMS switches.
Actuation voltage wave-form dependence of charge accumulation in RF MEMS switches
Show abstract
RF MEMS capacitive switches hold great promise in commercial, aerospace, and military applications. However,
their commercialization is hindered by reliability concerns: charging effect in the dielectric layer can cause irreversible
stiction of the actuating part of the switch. Presently, a popular method to investigate the charging/discharging in the
dielectric layer is to measure an actual RF MEMS capacitive switch, which means a high experimental cost in fabricating
MEMS switch devices.
In this paper, a Metal-Insulator-Semiconductor (MIS) capacitor is used to investigate the charge accumulation in
the dielectric layer of RF MEMS switches. By measuring the capacitance versus voltage (C-V) curves of MIS capacitor
after voltage stressing, the dielectric charging/discharging characteristics are obtained. The experiment results indicate
that the injected charges from the metal bridge in RF MEMS switches are responsible for stiction phenomena. In SiNx
dielectric, the hole capture is more favored over electron capture, and the trapped charges tend to inhibit the charges
further injecting. The effects of the actuation voltage waveform on the charge accumulation in the dielectric layer were
investigated. It is verified that the tailored actuation voltage waveforms can be used to improve the reliability of RF
MEMS capacitive switches.
Sensor
Integrated microsensors and systems
Shanhong Xia,
Jizhou Sun,
Lan Qu,
et al.
Show abstract
Our recent research on the integrated micro biosensor systems was presented in this paper. Monolithic
ISFET (ion-sensitive field-effect transistor) pH sensor and microelectrode amperometric immunosensor based
on the micro/nano fabrication technology were studied. The Monolithic ISFET sensor, including the
differential ISFET/REFET sensing device and the signal-processing circuit integrated on a single chip, was
fabricated by standard CMOS and MEMS technology. Amperometric immunosensors were prepared based on
MEMS technology with different microelectrode system and novel antibody immobilization methods. Both
kinds of the sensors show attractive advantages, such as miniaturization, compatibility with CMOS techniques,
easy to be designed into micro array and enables relatively rapid, reliable and inexpensive field-analysis.
Research and fabrication of harmonic oscillator with high quality in Si-based MOEMS acceleration seismic geophone
Show abstract
A kind of photo-electronic integrated acceleration seismic detecting technology, which is novel and precise based on
waveguide M-Z interference, is presented. It provieds modern geologic prospect with a novel detection technology. The
principle of the photo-electronic integrated acceleration seismic geophone is introduced in this paper. The core of the
photo-electronic integrated acceleration is the silicon harmonic oscillator, which is supported by four silicon beams and
integrated on the signal beam of the M-Z interferometer. When the seismic mass is subjected to a normal acceleration
az, the acceleration az, will result in an inertial force Fz, causing the mass to move up or down like the piston, until the
counter force of the beam suspension equals this inertial force. The principle of the harmonic oscillator is briefly
introduced, the factors influencing the anisotropic etching quality of the harmonic oscillator are analyzed in detail. In
experiment, the fabrication technology was studied and improved. The high quality harmonic oscillator has been
successfully fabricated. It has been applied in the integrated optical chip of "the theory and experiment research of
photoelectric integrated acceleration seismic geophone technology".
A silicon micromachined infrared emitter based on SOI wafer
Show abstract
An improved fabrication technique for silicon-based MEMS (MEMS: microelectromechanical systems) Infrared (IR) emitter is presented. The IR emitter was fabricated on silicon-on-insulator (SOI) wafer. The resistively heated polysilicon membrane fabricated by using deep reactive ion etching (DRIE) process on backside of SOI wafer has a low thermal mass structure, thus this IR-emitter can be modulated at high frequency. Additionally, the usage of the DRIE process instead of the wet etching process provides a more optimum design for the chip dimension. An appropriate boron (B) dope was used to realize the infrared absorption of silicon or infrared transparence of silicon for achieving self-heating or body emitting effect. By using the SOI wafer, the fabrication processes are simplified, and the production costs are decreased. The membrane temperature and emission spectrum of IR emitter were measured with thermal imaging system and spectroradiometer. The experimental results show that the IR emitter exhibits a strong emission in middle infrared range, and the modulation frequency can reach to 45Hz at 50% modulation depth. It is expected that this IR-emitter can be used in low cost sensing system.
A laser-induced fluorescence optical fiber detection system for micro-fluidic chip
Show abstract
Based on optic fiber beam sensor, a miniaturized laser induced fluorescence optical fiber detection system using solid-state laser (473nm) as excitation source is developed. The advantage of the
LIF-D system are simple structure, small size, low cost, high sensitivity and high anti-disturbing. And the photon count method is used to improve the sensitivity of the detection. Using Sodium fluorescein as the test sample, distinct fluorescence signal with good repeatability is showed in the experiment. The concentration detection limit is up to 3×10-13mol/L. the linear dynamic range is from 10-6 to 10-13 mol/L. It also shown that there was a nicer linear relation between the peak value of fluorescence signal to Sodium fluorescein concentration. Its relation coefficient is 0.99954. By changing detection cells this integrated detection system can be applied in micro flow analysis and for the normal biotechnology analysis of DNA.
Micro amperometric immunosensor by antibody immobilizing with electropolymerized protein A
Chao Bian,
Jizhou Sun,
Lan Qu,
et al.
Show abstract
A micro plane amperometric immunosensor for the detection of human immunoglobulin G is fabricated on silicon
wafer based on Micro-Electro-Mechanical Systems (MEMS) technology. This microsensor is an electrochemical system
composed of two-electrode (working electrode and counter electrode) integrated with a micro reaction cell made of SU-8
photoresist. The sensitive area of the working electrode is only 1 mm2.
A new method for the orientation-controlled immobilization of antibody based on staphylococcal protein A (SPA) and
polypyrrole (PPy) is developed, which is fast, controllable and proper to microelectrode. PPy as a transition layer is first
electropolymerized at the sensing area of the working electrode. Then SPA is co-electropolymerized with PPy for further
orientedy immobilization of antibody. The electrodes modified by PPy and the coelectropolymer of PPy and SPA were
characterized by SEM. HIgG range from 5 ng/ml to 640 ng/ml can be detected by this immunosensor with less
consumption of reagent and acceptable reproducibility and stability.
Sensor and Actuator
Optical fiber accelerometer based on MEMS torsional micromirror
Show abstract
A novel structure of optical fiber accelerometer based on MEMS torsional micro-mirror is introduced, including MEMS
torsional micro-mirror and optical signal detection. The micro-mirror is a non-symmetric one, which means that the
torsional bar supporting the micro-mirror is not located in the axis where the center of the micro-mirror locates. The
optical signal detection is composed of PIN diode and dual fiber collimator, which is very sensitive to the coupling angle
between the input fiber and output fiber. The detection principle is that acceleration is first transformed into torsional
angle of the micro-mirror, then, optical insertion loss of the dual fiber collimator caused by the angle can be received by
PIN. So under the flow of acceleration to torsional angle to optical signal attenuation to optical power detection, the
acceleration is detected. The theory about sensing and optical signal detect of the device are discussed in this paper. The
sensitive structure parameters and performance parameters are calculated by MATLAB. To simulate the static and modal
analysis, the finite element analysis, ANSYS, is employed. Based on the above calculation, several optimization methods
and the final structure parameters are given. The micro-mirror is completed by using silicon-glass bonding and deep
reactive ion etching (DRIE). In the experiment, the acceleration is simulated by electrostatic force and the test results
show that the static acceleration detection agrees with the theory analysis very well.
A novel optical MEMS pressure sensor with a mesa diaphragm
Show abstract
A novel pressure sensor with a mesa structure diaphragm based on microelectromechanical systems
(MEMS) techniques is presented. The operating principle of the MEMS pressure sensor is expatiated
by the Fabry-Parot (F-P) cavity model and the relation between pressure and interference light intensity
is deduced in the sensor. The mechanical model of the mesa structure diaphragm is validated by
simulation, which declares that the mesa structure diaphragm is superior to the planar one on the depth
of parallelism. Experimental system is also introduced.
Characterizations of microcantilever chemical sensors based on SOI material
Show abstract
This paper focuses on the study of sensitivities of microcantilever chemical sensors based on SOI POLYMUMPS
process. Through changing the geometry of beams and analyzing resonance frequency shift in a dynamic mode by using
FEA (finite element analysis) method, the most sensitive structure, which is a triangle, is selected out from various kinds
of beam designs. The relation between the sensitivity and the parameters such as length L, width W and thickness t is
obtained by dynamic analyzing with the commercial software Intellisuite. This research provides the primary instruction
for developing high sensitive multi-array biochips aiming at analyzing multiple parameters in parallel.
Poster Session
Study on the image processing algorithms for optical readout based uncooled MEMS IR imager systems
Show abstract
MEMS thermal transducers offer a promising technological platform for un-cooled IR imaging. We report on the
fabrication and performance of an optical readout based MEMS IR FPA based on the bimaterial microcantilever.
For the IR images of objects obtained by these FPAs, processed by the fast Curvelet transform denoising and
inpainting algorithm, the image quality is improved obviously. Great compute and analysis have been realized by
using the discussed algorithm to the simulated data. The experimental results demonstrate, better RMSE and
highest Peak Signal-to-Noise Ratio (PSNR) compared with traditional methods can be obtained. At last we discuss
the factors that determine the ultimate performance of the FPA. And we indicated that one of the unique
advantages of the present approach is the scalability to larger imaging arrays.
Research of the digital coding mask based on digital micromirror device
Show abstract
An approach, which is used to fabricate diffractive optical elements (MOEs), is presented by applying reduction
projecting system based on digital micro-mirror device (DMD). In this paper, coding-mask is combined with DMD
which is real-time, flexible and easy for alignment. Pre-distortion according to the non-linear effect in the aerial
image and resist course can be implemented. The accumulation of exposure energy can be obtained through
modulating rotating velocity of mask graphics, and finally distribution of exposure, which is required, can be
achieved. It shows that the method is practical and feasible on the grounds of the results of MATLAB simulation and
experiments.
Fabrication of wall array by electrochemical etching of n-type silicon
Show abstract
Electrochemical etching of patterned n-type silicon in hydrofluoric acid (HF) solution has been employed as a useful
micromachining technique. In this paper, 4 um pitch regular wall array structures with high aspect ratio (larger than 20)
were fabricated in n-typed silicon with back side illuminating. Differing from common hole array's fabrication,
undesired formation of separated pores along the trench bottom becomes a serious problem in the wall array's
fabrication. By adjusting the etching current density, we have successfully suppressed this phenomenon. A theoretical
analysis of the formation mechanism of wall array will also be discussed in this paper.
Piezoelectric capacitive power generator from vibration energy
Show abstract
A vibration-powered micro-power-generator has been presented in this paper, which has integrated two different energy
harvesting mechanisms, e.g., Capacitive and Piezoelectric Mechanisms. The periodic vibration of the mass on movable
electrode causes the variation of the capacitance, and the strain in the piezoelectric film. These two mechanisms can
harvest the vibration energy and generate current in the output circuit. By using two different metals with large difference
in working function as the two electrodes of the capacitor, our design, the combination of these two different scavenge
mechanisms, can overcome the dependence of the traditional capacitive converter on the separate voltage source and
improve the efficiency of power conversion. The volume of the designed device is less than 0.8 cm3. The simulated
results reveal that this energy converter can provide an average output power of 82.21μW at an external vibration with a
frequency of 111.4 Hz and amplitude of 0.2g.
Charge accumulation in composite dielectric layers in capacitive RF MEMS switches
Show abstract
In this paper, our work is focusing on investigating the mechanisms of the charge accumulation in dielectric layer of RF
MEMS capacitive switches. In our experiments, silicon-nitride and silicon-oxide composite films, e.g., SiO2+Si3N4 and
SiO2+Si3N4+SiO2 films are chosen as the dielectric layers for study. The composite films were prepared by thermal
oxidation and PECVD process. The Metal-Insulator-Semiconductor (MIS) structure was produced by using the
composite films as the dielectric layer. The capacitance versus voltage (C-V) measurement is employed to study the
space charge injection and relaxation process in the composite films. The results show that the charge accumulation can
be reduced by using the composite films structure.
MEMS for vibration energy harvesting
Show abstract
In this paper, a capacitive vibration-to-electrical energy harvester was designed. An integrated process flow for
fabricating the designed capacitive harvester is presented. For overcoming the disadvantage of depending on external
power source in capacitive energy harvester, two parallel electrodes with different work functions are used as the two
electrodes of the capacitor to generate a build-in voltage for initially charging the capacitor. The device is a sandwich
structure of silicon layer in two glass layers with area of about 1 cm2. The silicon structure is fabricated by using
silicon-on-insulator (SOI) wafer. The glass wafers are anodic bonded on to both sides of the SOI wafer to create a
vacuum sealed package.
Study for steel ball surface quality detecting based on vision technique
Show abstract
Bearing is a basic work-piece in machinery devices, and surface quality of steel ball is the main factor which affects the
precision and longevity of bearing. Currently defects of steel ball are detected manually in industry. It is inefficiency and
of high probability of misidentification. In order to assure the stability of steel ball quality this paper put forward an autodetection method based on vision technique to detect surface defects of steel ball. Firstly we designed an approach to
fully expand the surface of steel ball according to the requirement of image detection. Then we made up a corresponding
device to accomplish to designed approach and developed a platform system for image detection. Finally we carried a
proving detection in some kind of defects of steel ball. The result of test shows that the method can be put into use to
detect the general defects detection of steel ball.
Design of maskless lithography system based on DMD
Show abstract
An experiment system of maskless lithography has been presented using the characteristics of digital micro-mirror
device (DMD) and principle of light refraction and diffraction. The experiment system contains a worked lamp-house, a
DMD controlled by computer and an imaging system. The main parameter of devices, such as the incident and reflected
light on DMD by selection of optimal optical devices and realizes process of exposure have been designed. In this paper,
the particular characteristics of this system were described and some preliminary experimental results were discussed in
finally. With this system, the realizable rate of reduction projecting is 14; the minimum precision is 1.3μm. It avoids the
process of replacement mask and subsequent problems, and simplifies operation process, improves overlay accuracy,
shortens production cycle of IC, and greatly decreases production cost. It is convenient to actualize the process of
exposal and optional to replace the digital mask. These can provide possibility for maskless lithography being further
improved.
Study about the thermal adaptability of mirrors based on MOEMS for satellite-borne laser beam control used in multiple targets tracing
Xiaofeng Li,
Hua Zhang,
Yujun Yuan
Show abstract
The development of miniature, light-duty and low power consumption satellite-borne new concept devices based on
MOEMS has significant meaning to realize forming inter-satellite network and minimizing, integrating, intellectualizing
the payload of satellite-borne laser communication system. Agile beam steering control system based on MOEMS can
realize the large FOV, high precision, agile response trace and optical axis alignment for multiple targets in spatial
optoelectronic system. Comparing to traditional technology, agile beam steering control system lower the volumes,
reduce the weight and power. In this article, ANSYS thermal analysis software is used to simulate the thermal distortion
of the micro-mirrors on the MOEMS. ZEMAX optical analysis software is used to simulate the outgoing beam before
and after the distortion of the mirrors. Under certain conditions, high power laser beam will have thermal effect on the
reflector based on the reflective MOEMS APT precise steering device. The simulation results show that: the thermal
distortion of the micro-mirror is tiny when radiated by low power laser, the influence can be neglected. However, when
the laser power increasing, the receiving power decreased, the system performance degraded. In order to mitigate the
negative influence, relevant method must be adopted.
A novel microscanning device
Show abstract
The microscanning technique can improve a detector's capabilities in infrared focal plane array imaging. A
common way to realize the microscanning technique is to utilize an actuator to make a reflector swing.
Here a novel microscanning device is presented in this paper. The principle is on the condition that a spring
subassembly matches the actuator, a reflector swings with high frequency. There are two methods of realizing the novel
device. One is that the output of the spring subassembly is set as a variable parameter, so the spring subassembly and
other elements make up of a spring system. Controlling the frequency and amplitude of the spring subassembly can
realize the microscanning function. The other one is that the output of the spring subassembly is set as an invariable
parameter, controlling the rotary acceleration of the reflector can realize the microscanning function.
The different controllable modes of the two methods are established. In the two methods, controllable parameters
are the rigidity coefficient of the spring, the advance compressing distance of the spring, the distance between the axis of
the actuator and the rotary axis of the reflector, the rotary inertia of rotary units.
The experiments show that the two methods all can realize the novel device, and the second method is better than
the first one.
Study on bandwidth mutual benefit between the azimuth and pitch in an optoelectronic tracking system
Show abstract
Two-axis optoelectronic tracking equipments generally use such mode that azimuth and pitch system are independently
controlled. It leads to the two structures completely uncoupled, and reduces the state space dimension. But the main
problem is that the rotational inertia of azimuth is much larger than that of pitch, which leads its dynamic tracking
performance is worse. So to find a more suitable mechanics and more effective control strategy is necessary. Considering
the tracking ability, this paper designs BMC (bandwidth mutual compensation) to uniformly correct the error of both the
azimuth and pitch system in real time, it is realized by cross coupling control to the azimuth and pitch. The simulation
result verified that compared with classical uncoupling system BMS not only guarantees the state space dimension but
improves systematic tracking performance about 2" therefore, it is an effective control mode to the two-axis photoelectric
tracking equipments.
An electromagnetically actuated fiber optic switch using magnetized ferromagnetic materials
Show abstract
This paper presents the design, fabrication and testing of a fiber optic switch actuated electromagnetically. The
ferromagnetic gel coated optical fiber is actuated using external electromagnetic fields. The ferromagnetic gel consists of
ferromagnetic powders dispersed in epoxy. The fabrication utilizes a simple cost-effective coating setup. A direct
fiberto-fiber alignment eliminates the need for complementary optical parts and the displacement of fiber switches the laser
coupling. The magnetic characteristics of magnetized ferromagnetic materials are performed using alternating gradient
magnetometer and the magnetic hysteresis curves are measured for different ferromagnetic materials including iron,
cobalt, and nickel. Optical fiber switches with various fiber lengths are actuated and their static and dynamic responses
for the same volume of ferromagnetic gel are summarized. The highest displacement is 1.345 mm with an input current
of 260mA. In this paper, the performance of fiber switches with various coating materials is presented.
An optical scanner based on cantilever-type electrostatic zipping actuators
Show abstract
This paper discusses modeling, design, fabrication and characterization of an optical scanner based on cantilever-type
electrostatic zipping actuators. The electrostatic actuator has been designed to achieve high displacements for large
optical scanning angles at lower actuation voltages. The zipping actuators are fabricated using multi-layer polysilicon
foundry fabrication processes. The electrostatic force between the cantilever and the bottom electrode on the substrate
pulls the cantilever down. With a warped cantilever, the force closes the gap from the anchored end and gradually the
zipping effect actuates the entire cantilever. In our design, mechanical structures are arranged to avoid electrical shortcircuit.
With various annealing temperatures, the warped angles are controllable. The cantilever serves as a reflective
surface and the high out-of-plane displacement is used to steer a reflected laser beam for imaging and scanning
applications. In this paper we present the design considerations in electrostatic zipping actuator displacement and
control as well as the arrangement for optical scanning.
A fast initial alignment of MIMU in the two-dimension trajectory correction fuze for spinning projectile on stationary base
Show abstract
In the paper, a fast initial alignment of strapdown MIMU used in the two-dimension trajectory correction fuze was
analyzed. According to the situation that MIMU can't work normally because of high shock on shrapnel of Compound
Extended Range by Base Bleed and Rocket at firing, the MIMU in initial alignment with Bar-Itzhack and Berman's error
model is presented and the observability was analyzed. It shows that the observability of MIMU on stationary base is
poor. The selection of unobservable states was discussed. A Kalman filter estimation algorithm was provided, but the
azimuth error converges very slowly in initial alignment. A fast estimation method of the azimuth error was proposed. It
reveals that the azimuth error can be entirely estimated from the estimates of leveling error and leveling error rate
without gyro output signal. It shows that the method can realize the rapid initial alignment of MIMU.
Multi-path optical fiber sensor for atmospheric pressure
Show abstract
Micrometric displacement sensor with optical fiber was employed to inspect deformation of membrane box with air pressure changing, in order to avoid the defects in inspecting deformation, or improve and optimize performances of the sensors. A multi-path optical fiber sensor was utilized to measure the displacement, so that sensitivity is increased, and a little changing in air pressure may be measured. The relation between optical fiber sensor output changes and atmospheric pressure changes was standardized with a standard air pressure gauge. A setup for measuring atmospheric pressure was formed, the experiment results indicate that measurement range is 500-1060hpa, resolution is 0.2hpa, and accuracy is ±0.2hPa.