Proceedings Volume 6717

Optomechatronic Micro/Nano Devices and Components III

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Proceedings Volume 6717

Optomechatronic Micro/Nano Devices and Components III

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Volume Details

Date Published: 8 October 2007
Contents: 5 Sessions, 30 Papers, 0 Presentations
Conference: International Symposium on Optomechatronic Technologies 2007
Volume Number: 6717

Table of Contents

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Table of Contents

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  • Front Matter: Volume 6717
  • Micro/Nano Devices and Components
  • Manipulation and Assembly of Micro/Nano Devices and Components
  • Invited Session: Composite Doped Metamaterials
  • Inkjeting and Optical Devices
Front Matter: Volume 6717
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Front Matter: Volume 6717
This PDF file contains the front matter associated with SPIE Proceedings Volume 6717, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference and Symposium Committee listings.
Micro/Nano Devices and Components
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Improved performance of thin film broadband antireflective coatings
Matthew Mishrikey, Arya Fallahi, Christian Hafner, et al.
Antireflective coatings are useful for a range of applications, from minimizing the radar cross-section of stealth aircraft, to maximizing the efficiency of solar energy panels. New low-index nanorod thin films promise broadband, broad angle performance for such coatings. We demonstrate that a bandwidth increase from 38.5% to 113% is possible by using a simple evolutionary strategy to optimize the thin film material parameters. A two dimensional FDTD planewave periodic scattering approach is used to demonstrate additional performance increase by adding losses to a single layer. The same technique may be used for antireflective coatings for which no analytical solution exists, as is the case with dispersive, non-linear materials, special geometries, and coatings with metallic or ferromagnetic inclusions. A procedure is outlined for using the FDTD approach to obtain a map of reflection coefficients with respect to wavelength and incidence angle.
Quantum information processing using nanoscale objects embedded in photonic crystals
Hiroyuki Nihei, Atsushi Okamoto
We have demonstrated the coherent control of nanoscale objects (such as quantum dots) embedded in photonic crystals, which provides a basis for a one-qubit phase rotation gate that is one of the universal quantum logic gates for quantum information processing. In this demonstration, the quantum electrodynamics of the atomic system is calculated by the Schrödinger equation. Using the results of the calculation, the quantum electrodynamics is graphically represented by a Bloch sphere. This shows that the quantum state is rotated on the Bloch sphere, and this rotation is stopped or started, depending on the laser phase, which can act as a one-qubit phase rotation gate.
Thermo-optical delay line for optical coherence tomography
Eduardo Margallo-Balbás, Gregory Pandraud, Patrick J. French
Optical Coherence Tomography (OCT) is a powerful medical imaging technology. Its ability to non-invasively probe tissues in depth with high resolution has lead to applications in many fields of medicine, with a large potential for surgical guidance. One of the technological challenges impairing faster adoption of OCT is the relative complexity of the corresponding optical instrumentation, which translates into expensive and bulky setups. In this paper a compact fast-scanning optical delay line based on the thermo-optical effect of silicon is studied. Although this effect has been applied to other optical components, the necessary frequency behaviour together with the relatively large scanning range required are unique to the application. Cycling speeds of over 1kHz and ranges of more than 1mm are needed for video-rate acquisition of relevant tissue volumes. A structure is proposed to meet these specifications. A bulk micro machined freestanding waveguide is connected to the substrate by means of evenly spaced support beams. It is shown by means of the Finite Element Method that the geometrical parameters of the beams modulate the thermal behaviour of the waveguide. A linear trade-off between maximum working frequency and power dissipation for any given waveguide size and required scanning range has been found. Our results show that the proposed implementation of a fast-scanning delay line can match the requirements of Time Domain Optical Coherence Tomography.
MEMS tunable silicon Fabry-Perot cavity
Jonathan Masson, Fatou Binetou Koné, Yves-Alain Peter
In this paper we present an innovative tunable Fabry-Perot cavity micromachined in silicon. A short summary of the theoretical background of these filters is presented, followed by technical requirements for the design of the dielectric mirror composing the Fabry-Perot cavity and the cavity itself. Simulations and experimental data are demonstrated to be in good agreement. An in plane design is used to allow easy fiber alignment. The Fabry-Perot is tuned by an electrostatic comb drive actuator supported by a set of four springs to achieve a uniform modulation of the air gap of the filter. Only 15.4 V are required to tune the Fabry-Perot over 73nm bandwidth (covering more than the whole C-band) with a FWHM varying from 6 to 10nm. Transmission losses are -11dB.
Soft lithographic fabrication of microresonators
Andrea M. Armani, Kerry J. Vahala
As new synthetic, low-loss polymers are developed, polymer optical cavities are experiencing a revolution, in both fabrication design and functionality. Recently a fabrication technique was developed which enabled planar arrays of polymeric resonators to achieve cavity Q factors greater than 1 million. This molding technique can be used to fabricate resonators from polymers which have either thermal or UV curing mechanisms. These resonant cavities demonstrate quality factors which are competitive with photonic crystals and microdisk resonators and have applications in telecommunications and biological sensing.
Spectral boundary integral equation method for the characterization of novel photonic nanomaterials
The Spectral Boundary Integral Equation method for the numerical modeling of superlenses formed by metamaterial is proposed. The corresponding transmission problem is formulated using a classical approach based on layer-potential technique. The obtained system of integral equations is solved by using the Galerkin's method with approximations based on spectral harmonics on the unit circle. A singularity subtraction technique is applied to avoid numerical instabilities caused by the integral equation singularities. The novel idea is the global parameterization of the non-smooth boundaries of the rods in terms of Fourier series by using a conformal mapping technique. The numerical instabilities that may be caused by the geometrical singularities of the rods are eliminated. The developed simulation tool based on this method provides solutions with high accuracy and reduced complexity. These features permit to investigate the dependence of the lens characteristics on the shape and orientation of its structural details, and their material properties.
Re-Ir coating effect of molding core (WC) surface for aspheric glass lens
Sang-Suk Kim, Hyun-Uk Kim, Hye-Jeong Kim, et al.
Recently, with increasing lightness and miniaturization of high resolution camera phones, the demand for aspheric glass lens has increased because plastic and spherical lenses are unable to satisfy the required performance. An aspheric glass lens is fabricated by high temperature and pressure molding using a tungsten carbide molding core, so precision grinding and coating technology for the molding core surface is required. In this paper, the optimal grinding condition of the tungsten carbide molding core was found after applying DOE to the development of the aspheric glass lens for the 3 mega pixel and 2.5 magnifications optical zoom for camera phone module. Also, the ultra precision grinding process was investigated under this condition by experiment. Rhenium-Iridium(Re-Ir) coating was applied on the ground surface of the tungsten carbide molding core. The influence of Re-Ir coating on the form accuracy and surface roughness was compared and evaluated. The form accuracy and surface roughness of the molding core were improved by application of Re-Ir coating on the surface of the tungsten carbide molding core. Aspheric lenses were also molded with the non-coated molding core and the Re-Ir coated molding core. Form accuracy(PV) and surface roughness(Ra) were measured. The form accuracy of the aspheric glass lens improved about 0.01 μm (aspheric surface) and the surface roughness by about 0.5 nm (aspheric surface).
Study on pressing conditions in the molding of aspheric glass lenses for phone camera module using design of experiments
Hye-Jeong Kim, Du-Hwan Cha, Sang-Suk Kim, et al.
Recently, the application of aspheric glass lenses is rapidly expanding due to the availability of mass production employing the glass molding press(GMP) process. To date, the GMP process has been regarded as one of the reliable methods in fabrication of aspheric glass lenses. However, it has been found that there are some difficulties during the process to control many parameters (e.g. molding temperature, pressing time and pressing force, etc). Design of experiments (DOE) is one of the solutions to properly control these parameters and a useful tool in the process and analysis of complicated industrial design problems. This study investigated the pressing conditions in the molding of aspheric glass lenses for the mega pixel phone camera module using the DOE method. The fractional factorial design is applied and the form accuracy (PV) of the aspheric surface of the molded lens is employed as a response variable. The analysis results indicate that the only two main effects, the time of pressing step 2 and the force of pressing step 1, are available for the form accuracy (PV) of the molded lens. It is the optimum condition among the designed pressing conditions for lowering the form accuracy (PV) value that all factors are at their low levels. The form accuracies (PV) of the mold and molded lens under the optimum condition are 0.181 um and 0.22 um, respectively.
Investigation of optical amplification in Si-Nanocrystal-Er doped optical fibers
A. Rostami, A. Salmanogli, F. Janabi Sharifi
In this paper, we study in detail the optical properties of the Er and silicon nanocrystal doped fiber amplifier system in steady state case. This analysis is based on energy coupling between each silicon nanocrystal and the neighboring Er(+3)ions. Also, we consider the interaction between pairs of Er ions such as cooperative up-conversion mechanism and concentration quenching effect. The proposed method is used the rate equation as fundamental basis for description of the light interaction with nanocrystals and Er ions. We show that with introducing Si-nanocrystals into Er doped fiber, amplification process strongly improves and the fiber length of the fiber amplifier for a given gain is reduced compared to traditional cases. In this paper, limiting factor Kexiton governing the maximum number of exitons that can coexist within a single silicon nanocrystal, has been introduced and it is shown that in the case of Kexiton=2, optical gain is considerably increased.
A proposal for high performance infrared photodetectors: effects of defect on optical absorption properties in GaN/AlGaN spherical potential
A. Rostami, H. Rasooli, F. Janabi-Sharifi
In this paper a novel spherical centered defect potential as a basic cell for high-performance photodetectors applicable in optical communication and other engineering tasks is proposed. The proposed structure has capability to prepare ultra high absorption coefficient and tunable wavelength. A complete analysis of the proposed structure based on the effective mass equation is done and optical intersublevel absorption of the introduced structure is investigated. Effects of the size and height of spherical potential and the width and height of defect on optical intersublevel absorption are examined. It is shown that with increasing the width and height of the introduced defect as well as the size and height of potential barrier a red shifted absorption peak is created. The magnitude of absorption peak fluctuates with the variation of dipole matrix element and occupancy of ground states and un-occupancy of excited states. The material used for the proposed structure is AlGaN/GaN.
Mechanically tunable photonic crystal
Steven Schrader, Steven Truxal, Sheeba Gandhi, et al.
Many technologies have been developed to actively change the band gap of a photonic crystal. While reasonable tuning speeds have been achieved, large simultaneous changes in band gap have not. This is suitable for optical switching and routing, however, a much larger tuning range is required for optical switching of multiple wavelength signals. In this paper, we show the design and analysis of a MEMS device which allows for higher tuning capabilities by leveraging the high strain achievable within a polydimethylsiloxane (PDMS) polymer attached to silicon comb drives. This novel design can lead to photonic crystals with more tunability than other state-or-the-art designs while maintaining acceptable speeds over 1 kHz.
Label-free detection of chemical messenger proteins
Andrea M. Armani, Scott E. Fraser, Kerry J. Vahala
Recently, quality factors greater than 100 million were demonstrated using planar arrays of silica microtoroid resonators. These high Q factors allow the toroidal resonators to perform very sensitive detection experiments. By functionalizing the silica surface of the toroid using antibodies, the toroidal resonators become both specific and sensitive detectors. Targeted detection of Interleukin-2, a cytokine which stimulates production of T cells, is demonstrated. Additional cross-reactivity experiments are also performed to verify the sensor's behavior in a more complex environment.
Optical performance of F-Theta lens for laser scanning unit
Dong-Kil Lee, Jun-Hyung Ahn, Sang-Suk Kim, et al.
Recently, the global applications of aspheric lens are expanding rapidly on the electronics, optical components, communications, aerospace, defense, and medical optics devices, etc. F-Theta lens, which is one of major applications of aspheric lens, is a core optical part in Laser Scanning Unit (LSU) because it mainly affects the optical performance of LSU. F-Theta lens is made of the plastic using the injection molding method because of its cost and weight. In this study, the mold core for F-Theta lens, which is consisting of two non-axisymmetric aspheric surfaces, was processed by fly-cutting method, and the form accuracy of the mold core was measured. The product of the F-Theta lens, which was fabricated by the injection molding method, was satisfied that can be applied to the actual specifications.
A miniaturized EDM device suitable to fixing on a robot
Yongjun Tang, Zhongning Guo, Yongjun Zhang
A miniaturized EDM (Electro Discharge Machining) device has been designed which is suitable to fixing on robot, and the whole system can motion mobile working. A novel control strategy of differential driving principle has been presented in order to solve the problem that electrode can't be revolved owing compact size has been resolved. Coaxial forced vibration of electrode is benefit for the evacuation of debris, and it helps to achieve stable and efficient machining. Analysis of harmonic response and the theoretical value of amplitude have been carried out. The optimal design of ultrasonic motor has been implemented using animate function of ANSYS and optimal design means, and the interference between teeth of stator has been avoided. Auto-frequency tracking has been completed, and electrode lateral vibration of electrode has been eliminated. Finally, the holes with figures of Φ85μm circle, Y have been machined.
Manipulation and Assembly of Micro/Nano Devices and Components
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Mechanical instabilities and piezoresistivity of SiGe/Si microtubes
Li Zhang, Lixin Dong, Bradley J. Nelson
Mechanical instabilities and piezoresistivity of individual rolled-up SiGe/Si microtubes are investigated using nanorobotic manipulation. By applying this technique, as-fabricated one-end-fixed SiGe/Si microtubes can be cut and picked up from the substrate to examine their mechanical and electromechanical properties in a free space. Individual SiGe/Si microtubes show typical Euler buckling when the uniaxial compressive load is larger than a critical value. Moreover, experiments show that 1.6-turn rolled-up SiGe/Si microtubes have similar mechanical stability to ideal seamless tubes though the former ones have a spiral-like cross sectional area instead of an ideal ring. According to the measured I-V properties, SiGe/Si microtubes show positive piezoresistivity under compressive loads.
InGaAs/GaAs helical nanobelts as building blocks for nanoscale optoelectronic devices
Gilgueng Hwang, Cedric Dockendorf, Dominik J. Bell, et al.
In this paper, we present the length reduction of optoelectronic sensors using conductometric InGaAs/GaAs helical nanobelts. The helical nanobelt contributes to improve the unit length responsivity of photodetector while maintaining high external quantum efficiency (EQE) per unit length. A nanorobotic assembly and characterization of 3-D helical nanobelts to create in-/out-of-plane optoelectronic sensors has been shown. High optoelectronic sensitivity was revealed from experimental investigation under an optical microscope and from light emitting diodes (LEDs) inside a scanning electron microscope (SEM). A probe type photodetector was assembled using nanorobotic manipulation and in-situ gold nanoparticle ink soldering.
Improved design of large 3D micromirrors for microassembly into an optical MEMS cross-connect
Mohamed A. Basha, Nikolai Dechev, Safieddin Safavi-Naeini, et al.
A robotic-based microassembly process has been successfully applied to the construction of a novel micromirror design for use in optical switching. This paper is devoted to the description of a modified microassembly technique to construct a 3-D rotating inclined micromirror (3DRIM) that incorporate large micromirrors. The microassembly process is based upon the PMKIL (Passive Microgripper, Key and Inter-Lock) assembly system. The new modified assembly technique uses three supporting microparts: Two support posts and one cross-support post. Details of the assembly process to construct the micromirror and the design of the microparts are described. The results of the assembly process are presented, along with examples of prototype 3DRIMs. The 3DRIM is used as a building element for 1×N optical switching systems and for N ×M optical cross-connects.
NanoHand: micro/nano system for automatic handling of nano-objects
S. Fatikow, V. Eichhorn, A. Steinecker, et al.
In the NanoHand project a system consisting of micro/nano based subsystems for automatic handling of nanometer sized objects like carbon nanotubes (CNTs) and nanowires (NWs) will be developed. The goals of the project are driven by the needs of upcoming semiconductor technology. Demonstrators will be built, which have a short term (a) as well as a long term (b) perspective: (a) automated decoration of scanning probe microscope (SPM) probes with (i) CNT-enabled supertips and (ii) supertips grown by focused electron beam induced deposition; (b) handling and assembly of CNTs for the construction of nanoelectronic devices. NanoHand aims to transfer results achieved in laboratories towards industrially applicable, automated handling system for nanoobjects and its applications. This paper reports the technical achievements of the first project year.
Micro-electro-fluidic module to control magnetotactic bacteria for micromanipulation tasks under an optical microscope
Walder André, Zhao Lu, Bechara Moufarrej, et al.
This project describes a Multi-Chip Module (MCM) that contains a microelectronic circuit and a microfluidic device that could be combined to implement a "bacterial microfactory". The microchip contains two decoders connected to arrays of horizontal and vertical wires respectively, forming a matrix used to process commands received from an external computer. The electrical current flowing through the matrix is generated from internal voltage-to-current converters. The electrical current circulating through a metal conductor generates a magnetic field that is used to guide the movement of Magnetotactic Bacteria (MTB) in the microfluidic device. The dedicated microfluidic device is micro-fabricated on a glass wafer. Preliminary results show that a single MC-1 MTB can push a 2 μm microbead at speeds reaching 100μm/s under the control of an external magnetic field of less than 10 Gauss. A Carl Zeiss microscopy software (AxioVision) is used to control and configure the Axio Imager Z1 optical microscope and allows us to develop customized plug-in with Visual Basic for Application (VBA). The control electronic die was hence programmed as a VBA module, simplifying interoperability between the control, data recordings and microscopy observations. The parallel port of an Intel Pentium 4, 3.0 GHz equipped with 2.87 Go of RAM running Windows XP was used to communicate with the circuit. Connected to the parallel port, two demultiplexers interface the chip and the port. Patterns to control the bacteria such as left-right and up-down displacements were implemented and tested. Other more complex patterns to capture, attract and repel the bacteria from the center of the chip were also designed and validated.
Room temperature GaN-GaAs direct bonding by argon-beam surface activation
Eiji Higurashi, Yuichiro Tokuda, Masatake Akaike, et al.
A room temperature direct bonding using surface activation by argon (Ar)-beam sputtering was applied to the bonding between gallium nitride (GaN) and gallium arsenide (GaAs). The silicon doped n-type GaN films used in this experiment were grown by metal organic chemical vapor deposition on (0001) sapphire substrates. The GaN film thickness is 3 μm with a surface roughness of approximately 0.22 nm (Ra) as measured by atomic force microscopy. The silicon doped n-type GaAs (100) wafers with a surface roughness of approximately 0.34 nm (Ra) were used as GaAs substrates. The GaN and GaAs samples were cleaned by sputtering with a 1.5 keV Ar-fast atom beam with 15 mA in the vacuum chamber (background pressure: 1.3×10-5~4.0×10-4 Pa). Then, the samples were brought into contact as quickly as possible with a load of 735 N at room temperature. After this process, GaN films were successfully bonded to GaAs substrates without any heat treatment. Cross-sectional scanning electron microscopy showed that most of the interface area was well bonded. The bonding strength was evaluated by die-shear tests. Although all samples were visibly separated from the interface rather than in the bulk region after die-shear tests, the estimated die-shear strength of GaN/GaAs structures was 1.5 -7 MPa. The advantage of our process is free from the various problems caused by the large thermal expansion mismatch during heat treatment in the conventional fusion bonding.
Invited Session: Composite Doped Metamaterials
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Optimization of metallic bi-periodic photonic crystals application to compact directive antennas
Nicolas Guérin, Christian Hafner, Rüdiger Vahldieck
This paper presents a theoretical, numerical and experimental study for the design of a three-dimensional directive antenna for microwave telecommunications (KU-band: 12-18 GHz) applications. The presented structure consists of a stack of 6 metallic crossed grids above a ground plane, which is potentially capable to replace parabolic antennas, because it is much more compact than classical solutions and uses a single patch as feeding device. Such structure acts as a metallic photonic crystal at the band edge or as an ultra-refractive metamaterial. A numerical 3D code computing the diffraction by metallic bi-periodic gratings, and a fast layer-by-layer approach, allows to model and to optimize this kind of antennas. Especially, it is reported how both directivity and frequency bandwidth can be improved simultaneously. Numerical results are confirmed by experiments in an anechoic chamber.
Analysis and optimization of frequency selective surfaces with inhomogeneous periodic substrates
Matthew Mishrikey, Christian Hafner, Rüdiger Vahldieck
A new type of metamaterial is proposed that may be considered as frequency selective surface (FSS), consisting of printed metal patches on inhomogeneous, periodic substrates. To analyze these structures a system of equations obtained from the Rigorous Coupled Wave Analysis (RCWA) is solved by the Method of Moments (MoM) with sub-domain rooftop basis functions and Galerkin testing functions. Several examples are outlined and analyzed using the MoM/RCWA technique. In order to validate the procedure, comparisons with a commercial time domain solver are performed. The introduced structures are designed using a micro-genetic algorithm in order to achieve artificial magnetic conductors (AMC) with optimum performance.
Study of metallic nanoshelled structures with rigorous electromagnetic analysis
Xudong Cui, Daniel Erni, Christian Hafner, et al.
The main goal of this paper is to present thorough investigations for the metallic nanoshelled structures with rigorous electromagnetic analysis. Two metallic nanoshelled structures are investigated; namely, single nano-shelled cylinder, and nano-shelled photonic crystals. A rigorous Maxwell's equations solver is used to get insights into the optical properties of the structures. Our numerical simulations show that it is difficult to shift the plasmon resonance to long wavelength (e.g. towards ten micrometers) in such a structure. Flat bands are found in the metallic nanoshelled photonic crystals when the lattice constants are much smaller than the operating wavelength. This would become interesting especially for realizing ultra-compact slow wave structures such as plasmonic devices with low group velocity. Several applications using nano-shelled particles as sensors, as substrates for surface enhanced Raman spectroscopy are also discussed in the paper.
Plasmonic nanostructures made from aluminum fabricated by EUV interference lithography
Y. Ekinci, H. H. Solak, C. David, et al.
Extreme Ultra Violet (EUV) interference lithography was employed for fabrication of large-area, sub-100 nm scale Al nanoparticles as well as free-standing aluminum hole arrays. We studied the optical properties of the fabricated Al nanostructures. The marked difference in Al, compared to Au and Ag, is that its plasmon resonances lie in the UV range. Thus, the high-frequency plasmon resonance of Al nanostructures enables the extending of plasmonic research into the UV range and opens up new possible applications of plasmonics.
On the role of the losses in metamaterials
Nicolas Guérin, Christian Hafner, Rüdiger Vahldieck
Contrarily to classic Right-Handed Materials (RHMs), the role of losses is crucial for composite materials called metamaterials such as Ultra-refractive Right-Handed Materials (URHMs) and Left-Handed Materials (LHMs). As the loss-free case for a metamaterial is not stable, a small variation of losses can drastically modify the expected properties of such a material. Thus, it is important to understand how the input of lossy term affects URHM and LHM aspects, and also to define, for each of them, the tolerance level for which the interesting metamaterial properties are still valid. The role of losses is investigated analytically and numerically, a full study about the action of the losses on all the properties is done. It is shown that those properties almost completely disappear for an LHM slab with loss tangent over 0.01, which at optical frequencies corresponds to a good material.
Engineering gold nano-antennae to enhance the emission of quantum emitters
Mario Agio, Giorgio Mori, Franziska Kaminski, et al.
We study the fluorescence enhancement of a single emitter coupled to two spherical gold nanoparticles and discuss the differences with respect to coupling to a single one. We also show that by changing the aspect ratio of the nanoparticles we can easily tune the plasmon-mediated enhancement from the infrared to the visible range. We present the fabrication of our nanoantennae by two alternative methods, namely X-ray interference lithography followed by focused ion beam milling and electron beam lithography. The manufactured structures are characterized individually by confocal microscopy.
Inkjeting and Optical Devices
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Effects of substrate treatments on silver ink-jet printing
Sang-Ho Lee, Kwon-Yong Shin, Jun Young Hwang, et al.
In this study, characteristics of silver ink-jet printing were investigated under various substrate treatments such as substrate heating, hydrophobic coating, and ultraviolet (UV)/ozone soaking. Fluorocarbon (FC) film was spin-coated on the polyimide (PI) film substrate to obtain a hydrophobic surface. The coated FC film surface was estimated to have a fairly hydrophobic nature in that it exhibited a large water contact angle of 110‐113°. Although hydrophobicity of the FC film could reduce the diameter of the printed droplets, the singlet images printed on the FC film surface showed irregularities in the pattern size and the position of the printed droplet along with droplet merging phenomenon. The proposed UV/ozone soaking of the FC film improved the uniformity of the pattern size and the droplet position after printing and substrate heating was very effective way in preventing droplet merging. By heating of the substrate after UV/ozone soaking of the coated FC film, silver conductive lines of 78‐116 μm line were successfully printed at relatively low substrate temperatures of 40 °C and 70 °C.
A study on driving waveform of a piezoelectric inkjet print head
Jun Y. Hwang, Myong Ki Kim, Sang Ho Lee, et al.
Inkjet printing technology with a drop-on-demand (DOD) inkjet head has been recognized as one of the versatile and low cost manufacturing tools in the electronics industry. However, general strategy to optimize jetting stability has not been understood well, because of the inherent complex multi-physics nature in inkjet phenomena. In this paper, an experimental approach has been adopted to attack this problem. Based on the driving voltage amplitude and duration as the main and controllable parameter, the jetting map of an OLED ink has been constructed and the effect of phase matching between pressure and surface waves at the nozzle tip has been discussed.
A new SPR sensing technique using a chip with a fabricated microstructure
Hiroki Okuno, Fumikazu Oohira, Nobumitsu Miyanishi, et al.
In this study, we proposed a new sensing method using a special SPR chip on which microstructures are fabricated, and performed a principle confirmation of the sensing feasibility using this chip. We examined a fabrication method of micro structures on the SPR chip that has a filter effect by the pillar structure, which can filter the target substance reaching to the detection area of SPR sensing. In order to confirm the filter effect of the micro structure on the SPR chip, we performed the principle confirmation experiment of the SPR sensing system using the fine particles. Next, in order to adapt to the biological molecules measurement, we performed the experiment using yeast cells and demonstrated the filter effect of this chip with the micro structure.