Recently, the ubiquitous environment in which anybody can reach a lot of information data without any limitations on the place and time has become an important social issue. There are two basic requirements in the field of information storage devices which have to satisfied; the first is the demand for the improvement of memory capacity to manage the increased data capacity in personal and official purposes. The second is the demand for new development of information storage devices small enough to be applied to mobile multimedia digital electronics, including digital camera, PDA and mobile phones. To summarize, for the sake of mobile applications, it is necessary to develop information storage devices which have simultaneously a large capacity and a small size. Korea possesses the necessary infrastructure for developing such small sized information storage devices. It has a good digital market, major digital companies, and various research institutes. Nowadays, many companies and research institutes including university cooperate together in the research on small sized information storage devices. Thus, it is expected that small form factor optical disk drives will be commercialized in the very near future in Korea.

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Magnetic hard disk drive (HDD) technology is believed to be one of the most successful examples of modern mechatronics systems. The mechanical beauty of magnetic HDD includes simple but super high accuracy positioning head positioning technology, high speed and stability spindle motor technology, and head-disk interface technology which keeps the millimeter sized slider flying over a disk surface at nanometer level slider-disk spacing. This paper addresses the challenges and possible approaches on how to further reduce the slider disk spacing whilst retaining the stability and robustness level of head-disk systems for future advanced magnetic disk drives.

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Thin, flexible, continuous structures known as webs are used in a wide range of industrial applications. These structures interact with the surrounding air in beneficial or detrimental ways, depending on the application and the process parameters. A review of the literature related to modeling and experimental work on (mostly) the steady state fluid-structure interactions is given. Equilibrium equations of web mechanics, and the inertia dominated and viscosity dominated air flows are presented. Simulation examples from four different industrial applications; web/air-bar interactions; roller/web interactions for permeable and impermeable webs; and the flat-top recording-head/magnetic-tape interactions, are presented.

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This paper presents the recent status of industry-university cooperative research activities in Japan for mechatronics of information storage and input/output equipment. There are three research committees for promoting information exchange of technical problem and research topics on head-disk interface in hard disk drives (HDD), flexible media transport and image printing process which are supported by the JSME, Japanese Society of Tribologists and the Japanese Society of Precision Engineers. For hard disk drive technology, Storage Research Consortium is supporting more than 40 research groups in universities to perform basic research for future HDD technology. The past and present status of these activities are introduced, particularly focusing on HDD and flexible media transport mechanism.

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MEMS (Micro Elecro-Mechanical Systems)に関する研究は1990年代にその基礎的な加工方法および原理研究が盛んに行われ,現在では多くの機能を集積化した集積化MEMSやMEMSの応用分野としてのマイクロTAS (Total Analysis Systems)に関する研究が盛んに行われている.本講演では,MEMSの現状と今後の展開に関して,研究事例も交えて述べる.

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This paper describes the development of a thermoelectric (TE) generator with a catalytic butane combustor. The TE generator is composed of a thermoelectric (TE) module, a catalytic combustor, an ejector to supply air to the combustor and an ignition heater. Liquid gases such as butane and propane are used as fuel. The combustor without a load (TE module) achieved self-sustaining combustion and electrical ignition using butane as fuel. When the TE modules were attached to the combustor, however, butane combustion was impossible and the combustion efficiency of hydrogen decreased. The generation test was performed by attaching two TE modules to the combustor and using hydrogen as fuel. The conversion efficiency reached 1.8% at an output power of 276mW. This study confirmed that the miniature TE generator is practical, if the performance of the combustor is improved.

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We propose the micro power generator utilizing the flow-induced vibration which converts kinetic energy into electricity. It is one of the factor technologies of Ubiquitous equipment and now its demand is increasing rapidly. We adopt the electrostatic induction power generator which has an advantage in micro scale. In preliminary experiment, we obtained 0.91μW power generation with self-excited oscillation of 0.25mm amplitude at 1100Hz.

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A dumping system for micro piezo actuator was studied. The actuator is designed for nano precise positioning with high speed motion control to apply the trucking system that follows an under 10nm width truck on a disk rotating over 6000rpm. So the required servo band of the actuator is closing to 10kHz even though the actuator has the first resonance near 5kHz. A dumping material is applied to reduce the magnitude of the resonance as a servo band goes beyond the resonance frequency with control system design. The dumping material consists of four layers that are adhesion tape, PET film, adhesion tape and a SUS plate. The first adhesion tape is pasted on the actuator frame. The viscoelasticity of the adhesion films dumps the vibration of the actuator by the differential mode between the frame surface and the SUS plate in operation. The dumping effect gets larger as the SUS plate getting thicker because the heavier SUS plate, greater inertia, makes larger differential mode. On the other hand, the heavier SUS plate makes the resonance frequency lower. In this paper, an idea of design to reduce the magnitude of resonance while maintaining the resonance frequency that converges the mass on viscoelasticity layers at where larger stress seemed to be occurred. The larger stress points were inspected by using FEM analysis. Effects of the method was evaluated experimentally. The result shows good. Both greater resonance mode reduction and higher resonance frequency are simultaneously obtained.

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We have developed micro-piezoelectric actuators using PZT thin films. PZT thin films with composition of Zr/Ti=53/47 were grown on the (111)Pt/Ti/Si substrates by rf-sputtering. Micro-cantilevers, composed of PZT thin films and Cr elastic layers, were successively fabricated as unimorph actuators with a length of 500um and width of 90μm. The tip deflection of the cantilevers was measured using a Laser Doppler Vibrometer and we observed piezoelectric vibration level as high as 0.62μm at a relatively small voltage of 5.0V. However, the micro-cantilevers had large initial bending because of residual stress in the PZT and Cr layers.

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Recently, the increase of track density in optical disk drives is very remarkable in order to achieve large capacity storage devices. It is important to design and develop the high speed head positioning control mechanisms with high accuracy. Therefore, this paper proposes the MEMS mirror piezoelectric actuator mechanism using PZT thin film as the control mechanism. This MEMS mirror is fabricated by using silicon-based micro machining technologies. In this paper, the deep etching of silicon as well as the sputtering was studied and the fabrication process of the MEMS-based head tracking micro-actuator mechanisms was developed.

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This paper proposes a novel micro actuator head mechanism for ultra-high density hard disk devices. In order to improve the recording density of hard disk drives, tracking control technologies that position heads on the track with high speed and high reliability is very important. Furthermore, head-disk spacing control technologies are also important to achieve contact recording. In this study, the micro actuator mechanism, that can operate independently in both tracking directions of in-plate and out-of-plate motions by using electrostatic micro actuators and the PZT thin films, were studied. This paper reports silicon micro machining process technologies. In other words, the fabrication process of a prototype actuator was discussed and developed by optimizing etching conditions, because the multi-step silicone etching process by ICP-RIE or RIE is important to fabricate the proposed micro actuator.

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This paper describes a high-speed positioning that uses a two-degree-of-freedom control in a ball screw driving table. The ball screw driving table is used to semiconductor-fabrication equipments, so high acceleration, high speed, and high accuracy are demanded. The two-degree-of-freedom control consists a feedback control to decrease a positional error, and a feed forward control to speed up the table. And velocity feedback control is added to control the table vibration. The control system is designed by the simulation that uses two-inertia model. High speed positioning of the table is verified by the experiment.

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The method for rapid and reversible motion control of a single biomolecular motor is a key technology for future goal of integrating biomoletular motors with organic-inorganic hybrid nanosystems. A device for controlling the temperature locally under the microscope with fast response, 71.5K/s and 56.9K/s for temperature rise and fall respectively, was manufactured. Rapid and reversible angular velocity control of a single F1-ATPase, a rotary biomolecular motor, was achieved by switching the temperature. The rotation assay at the temperature higher than around 50℃ was realized thanks to the rapid switching of the temperature. The torque of F1-ATPase was found to increase at higher temperature by subtracting the effect of viscous drag of water.

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New type of micromachined tweezers, named AFM tweezers, are presented. The AFM tweezers combine the function of nano objects manipulation with AFM observation so that they can pick up nano objects during AFM observation sequence. There are two types of AFM tweezers under developing; One is called chopstick-type AFM tweezers, and another is piston-type one, according to the gripping mechanism of the tweezers structures. Both devices have two thin probes sharpen by anisotropic etching of silicon and local oxidation of silicon techniques. In this paper, we describe concept and fabrication of AFM tweezers, and demonstrate a function of nano object pick-up.

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We have developed a few types of cell arraying device based on micro fabrication. One is for patch-clamp measurements, where the orifice is precisely machined using a focused ion-beam (FIB). To achieve leak-tight clamping, the irregularity of the orifice shape must be minimized, and FIB is found to be suitable for this purpose. Another is the use of lower-cost laser-machining, in combination with the surface treatment with a cell membrane-anchoring chemical, BAM, by which the membrane adheres to the orifice plate to spontaneously seal the gap between the cell and the orifice. Also developed is a cell arraying device made of organic thin-films having laser-machined orifices. In contrast to the conventional devices based on anisotropic etching of the silicon wafer, the method provides a low-cost disposable cell arrayer.

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Micropumps are one of the most important microfluidic components in Micro Total Analysis System (μTAS). We have developed a valveless micropump driven by traveling wave, and obtained high energy efficiency. In this paper, the valveless micropump was fabricated by the microfabricatin technique to verify the validity of the pumping principle. The micropump was composed of flexible walls of a microchannel with piezoelectric bimorph cantilevers. Traveling wave was induced on the surface of the microchannel by applying sinusoidal voltages to each piezoelectric cantilever with the different phase, and the peristaltic motion of the channel wall transports the fluid. The fluid flow of the proposed micropump was measured using Micro particle Image Verocimetry (MicroPIV). The traveling wave micropump driven by the piezoelectric actuators is a simple structure without valves and a low cost disposable device.

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The purpose of this research project is to develop a compact and wearable human blood extraction and drug delivery system applying to analyze a blood sugar level as a health monitoring system (HMS), which is called "Mobile Hospital", without a centrifugal separator and a large scale blood sampling system such as conventional glucose level monitors. The design concept is Bio-MEMS from the female mosquito's blood suction mechanism. We will apply the developed device to the wristwatch type HMS. It consists of (1) a painless microneedle, (2) an indentation unit using a shape memory alloy (SMA) actuator, (3) a micropump for human blood suction using a piezoelectric microactuator, (4) a bio-sensor to detect and evaluate the amount of Glucose in extracted blood using an enzyme such as Glucose oxidase, and (5) an micropump for insulin dosage. In this paper, we have especially reported design, production and performance of the above (3) to (5).

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A new concept of electrostatic droplet actuation based on field-induced deformation of the droplet is presented in this paper. The device consists of a diagonal fishbone-shaped electrode array with a hydrophobic coating. When energized with an AC voltage, a droplet dispensed on the electrode undergoes a periodical motion of flattening and restoring the spherical shape, and because of the geometrical asymmetry of the electrodes, its center of mass is shifted bit by bit in each cycle. The actuation speed as high as 2.4cm/s is achieved for a 1μL-droplet on a 240μm-pitch electrode array with 50Hz, 50 Vrms excitation. Droplet sorting and mixing are also demonstrated by bifurcating and merging electrode arrays. The method only requires a pair of planar electrodes that can be fabricated by a single-mask process, and a single-phase power supply, leading to a simple and low-cost droplet-based micro-chemical system.

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This paper describes evaluation of characteristics of air bubbles in micro channel. Micro channels for generation and separation bubbles ware designed and fabricated. Air bubbles about 50μm in diameter were generated repeatedly ,and trapped with micro channel to separate from the water. Air bubbles and flow around bubbles ware visualized using micro-PIV. Removal characteristic of bubbles ware evaluated by Reynolds number and Weber number. Scale effect was appeared while decreasing diameter of bubbles. Bubble energy for unit volume was proposed as the quantity to evaluate the adhesion bubbles and separate from the wall.

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This paper presents a directivity reconfigurable antenna for millimeter-wave communication. Reconfiguration is carried out by changing the dielectric constant of ferroelectric film. The ferroelectric film is composed of lanthanum modified lead titanate (PLT) and deposited on micro strip line by RF sputtering. The dielectric constant of PLT has temperature dependence, so by using heater elements we can change the dielectric constant of PLT film. Heater elements are laid out beside micro strip line. By switching heater element the dielectric constant is periodically changed, and the characteristic of antenna will be reconfigured. As a first step, we analyzed two kind of antenna device by using FDTD (Finite Difference Time Domain) method, and fabricated them. And we developed a new numerical analysis program using CIP (Cubic Interpolated Peudo-Particle Scheme) method.

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This study aims at visualization of the bio-molecules dissolved in the solution near the surface using evanescent wave light. A system was developed for the visualization, which consists of total reflection fluorescent microscopy, Intensified CCD camera and PIV image processing system. Brownian motion of particle with diameter of 100nm and the concentration near the wall was evaluated. Furthermore, to evaluate the effects of the wall, surfaces with hydrophilic and hydrophobic wettability are prepared. The results show that the wall effects on the average displacement of Brownian motion and concentration profile of the particles. It is suggested that interaction between surface and particles are effective for the Brownian particles. The technique is applicable for bio-molecules analysis.

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Patient-tailored treatments become possible by simulating behavior of organs, which is affected by the change of the environment such as dispensing of drugs. For example, it is necessary to detail the electrical and mechanical properties of a single living cell to build simulation model of heart. This paper proposes a novel planar patch-clamp device integrating electrode, micro-channel and micro-hole.

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The electrical properties and phase transition behavior of (Pb,La)(Zr,Sn,Ti)O_3 (PLZST) thin films prepared on (100)Pt/(100)MgO substrates by RF-magnetron spattering and investigated by X-ray diffraction, relative dielectric constant and P-E hysteresis loops. From X-ray diffraction all PLZST thin films are polycrystalline. With an increase in composition Ti, electrically field-induced AFE-FE switching field(E_<AFE-FE>) is depressed. But Polarization of ferroelectric state are almost equal. These indicate PLZST components is better around boundary between AFE_T and F_R for micro actuator.

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Cylindrical droplet formation in a W/O (water in oil) system of microchannel was analyzed experimentally and theoretically. The microchannel shape was modified to generate smaller droplet based on theoretical model. Numerical and experimental investigations were carried out with the novel microchannel. It is found that generated droplet was almost the spherical shape, since the diameter was smaller enough than the depth of microchannel. The results indicated that 3-dimensional and more precise theoretical model should be applied to realize the smaller droplet generation.

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Two-dimensional numerical simulation of cross sectional behavior of sheet moved along a handling path in electrophotograph equipment is reviewed. The two-dimensional analysis is very useful for layout design, because a lot of simulation jobs can run with various cases economically. In this paper, a computational method to analyze transient behavior of the sheet with friction force from a paper guide and gravity is explained. Furthermore, several studies of the behavior unique to electrophotograph equipment are shown.

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The continuous flexible thin materials such as news print, film, thin foil of metal, etc. are called web. This paper is described the pressure characteristics of the transporting web handling roller. In the experiments, for web of two types such as newsprint and PET film used. The pressure distribution of rotating guide roller is measured for using a pressure transducer for behavior combination of web width, web position and rotating roller speed. Moreover, velocity distribution between the web and rotating roller was measured in the inlet and outlet region by PIV. Air film thickness is measured for using a displacement sensor for behavior combination rotating roller speed. From the experimental results, the hydrodynamic behavior for two types of webs with different permeabilites is clarified. The vortexes generate in the inlet region and the reverse flow occurs in the outlet region. The change of pressure like spike was considered base on these phenomena.

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In the transportation system for continuous flexible materials such as paper, plastic film, metal foil, textile, most webs are very thin and consequently easy to buckle or wrinkle. Especially, in the case of paper-web, the creation of wrinkles is more often as compared with the case of plastic film or metal foil. The web wrinkling affects significantly the product quality and sometimes it leads to less profitability in the manufacturing operation. The paper-web wrinkles treated in this paper are caused by the roller misalignment and traction characteristics between web and roller in the transportation systems. The prediction model of paper-web wrinkles is formulated and some numerical calculation results are shown with experimental verifications for coated and uncoated paper-webs. Moreover, the idea of "web defect map" is presented for designing and safety operating the web transportation system.

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A web is a continuous, flexible materials such as paper, plastic film, metal foil, textiles etc. Web wrinkling is a problem which plagues the web process industries. Most webs are very thin and prone to buckle or wrinkle. The effects of wrinkling can range from compromised product quality to down time of a processing operation, leading to less profitability in the manufacturing operation. The web wrinkles which will be treated in this paper are those that can be affected by roller misalignment and friction characteristics between web and roller. It is shown how web wrinkles can be predicted and ultimately avoided in manufacturing operations. Prediction method is presented with experimental verifications.

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In the transportation system for continuous flexible materials such as paper, plastic film, metal foil, textile, most webs are very thin and consequently easy to buckle or wrinkle. Especially, in the case of paper-web, the creation of wrinkles is more often as compared with the case of plastic film or metal foil. The web wrinkling affects significantly the product quality and sometimes it leads to less profitability in the manufacturing operation. The paper-web wrinkles treated in this paper are caused by the roller misalignment and traction characteristics between web and roller in the transportation systems. The prediction model of paper-web wrinkles is formulated and some numerical calculation results are shown with experimental verifications for coated and uncoated paper-webs. Moreover, the idea of "web defect map" is presented for designing and safety operating the web transportation system.

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This paper describes theoretical and experimental studies of the paper transportation characteristics of a long rubber-layered roller and a long steel roller. In a paper transport mechanism with long rollers, normal force distribution in the longitudinal direction arises due to the bending deformation of the roller core and the inequality of the clamping loads applied at both ends of the rollers. First, this normal force distribution was numerically analyzed using the finite element method. Next, the friction drive characteristics between rubber and steel rollers was numerically analyzed. The velocity ratio between rubber and steel rollers was measured for various clamping loads experimentally. It was shown that the proposed analytical method can predict the velocity ratio between rubber and steel rollers precisely. Finally, the paper skewing due to the inequality of the clamping loads was numericaly analyzed. The paper skew angle was measured for various clamping loads experimentally. It was shown that the proposed analytical method can predict the paper skew angle precisely.

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It is important in design to prevent the device from trouble during carrying paper, in paper handling system such as ATM, which carries paper sheet at high speed. In this study, the behaviors of the paper, normal carrying, carrying through and jam, are analyzed for various design conditions of the device and some kind of the paper configurations by experiment and FEM, and the relations between paper behavior patterns and their conditions are investigated. As a result, prediction expressions for each trouble pattern are devised from frictional law and the causes of their patterns are discussed.

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We have developed a simulation system for judging the handling behavior of paper sheets. We investigated and classified several kinds of conditional sheets (folded, curled, torn, and wrinkled sheet) that can jam the paper handling guide. Their characteristic sizes were found by experimenting with and simulating handling behaviors, concentrating mainly on the FEM model and simulation method of a heading-fold sheet handled by a V-type guide. The system was developed by combining a 3-dimensional CAD system with the database of the sheets' FEM models. Simulated examples of conditional sheets obtained by the system demonstrate efficiency and usefulness of the system for paper handling guide design.

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In the paper feeding mechanism, it is important to feed the sheet paper without jamming under any conditions. To avoid sheet jamming, we need to control the paper flutter in the paper path. We proposed a concave carrying path under the feeding roller. This mechanical characteristic is achieved by controlling paper behavior at two edges of concave carrying path and feeding roller, so it can generate tension of paper under the feeding roller, and keeps the paper feeding path constant. We also investigated which mechanical parts have an effect on paper jam by using robust design method, and we made clear it is the most significant to change cross sectional area of the paper feeding mechanism.

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This study investigates a bead-carry-out (BCO) phenomenon in a two-component magnetic development system used for a color laser printer. It has been clarified by the experiment that the electrical conductivity of carrier beads and toner concentration are highly related to the critical pull-off field of the BCO. Based on this experimental evidence, a numerical calculation has been conducted on the electrical charge of a carrier chain in the electrostatic filed by the finite element method to deduce a critical force that the BCO takes place. It has been clarified by the experiment and the calculation that toner particles prohibit the electrical conduction of the chain and hence the charge is diluted in the chain over the critical concentration of toner particles in the chain. This results in the reduction of Coulomb force applied to the top of the chain and improves the BCO.

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A preliminary experiment was conducted to classify particle size from mixed particles utilizing electrostatic force. An experimental setup was composed of two parts. One was a parallel electrode array which transported particles by virtue of the electrostatic traveling wave and another was a charged separation roller located on the upper side of the array. It was demonstrated that particles were charged on the parallel electrodes and small particles were attached to the separation roller, when the traveling electrostatic wave was applied to the parallel electrode.

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Experimental research was conducted to investigate basic characteristics of micro fan utilizing ionic wind in pin-to-plate gas discharge field. When high voltage was applied between the electrodes, ionic wind flowed toward heated plate through a hole of plate electrode. This research was focused on optimization of the electrode configuration by investigating the performance of the fan and the enhancement of the local heat transfer coefficients. The main conclusions were: (1) Flow rate increased with the increase of the hole diameter, and in the same hole diameter, static pressure increased with the increase of the plate thickness. (2) A gap-to-hole diameter ratio of 0.86 was found to be an optimal value that gives the highest peak power and efficiency. (3) The enhancement of the heat transfer coefficients increased with the increase of the distance between the plate electrode and the heated plate.

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This paper proposed an electrostatic driving mechanism utilizing slanted-pillars without a lead to apply alternative step voltage to a movable electrode. The movable electrode fixed on the slanted-pillars was set on two parallel fixed electrodes. When one electrode was connected to V_0 and the other to the ground, the movable electrode was V_0/2 because capacitances between movable electrode and each fixed electrode are almost same. Alternative electrostatic force caused linear motion of the mover due to anisotropic feature of the friction between pillars and the fixed electrodes. The achieved velocity was about 500μm/s.

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To increase recording capacity of hard drives, accurate head positioning techniques are indispensable for achieving higher track density. This paper describes developed technologies for accurate positioning, one is a higher resonance actuator for higher servo bandwidth, and the other is a acceleration feed forward control to supress disturbances. And we will estimate head positionig technology for future higher TPI drives.

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A conventional spin-stand system which used to evaluate read-write performance of magnetic recording heads and media can not allow thermal drift of its mechanism and NRRO (non-repeatable run out) of its air spindle motor. Therefore, we proposed a precise track following actuator which was a piggyback style for the spin-stand system. The actuator consists of a piezoelectric element (PZT) and a stroke amplifying mechanism. We propose the design method of a PID controller to realize a specified servo bandwidth and improve the property of the high frequency region of the PID controller. The effectiveness of the proposed method is illustrated by the simulation and experiment results.

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The rapid increase in the recording density of magnetic disk drives has required decreasing the flying height of magnetic head sliders to approximately 10nm. Under such low flying height conditions, however, the heat generated by the high-frequency current in the writer coils and the rise in the ambient temperature both cause local protrusion of head elements. Such protrusion reduces the flying height below the design value, thus reducing the safety margin for head/disk interference. To analyze this problem, the heat transfer in the head slider, the thermal deformation of the head, and the flying height changes of the slider due to the deformation were numerically simulated. The parameter study showed that short pole and shields cause a smaller ambient-temperature-induced protrusion but a larger write-current-induced protrusion, i.e., a trade-off relationship exists.

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This paper describes the dynamics of contact sliders with nano textures fabricated by femto second laser processing. First of all, the femto second laser processing method was developed in order to fabricate the texture on the DLC thin film pad. The contact slider experiments were carried out by using the slider with nano-textures, and the influences of nano-textures on the friction and slider dynamic characteristics as well as the lubricant film thickness change were investigated. As a result, the friction and vibration characteristics have been remarkably improved by the texture. And it suggested that the optimum values of the height and area ratio of the texture were existed.

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In order to make clear the dynamic adhesion force of a slider in near contact regime, we experimentally investigated the dynamic collision motion of a spherical slider on a magnetic disk. We used the spherical glass slider with 0.5, 1, 2mm radius and the magnetic disks with different lubricant thickness of 0, 1, 2 and 3nm with and without UV treatment. As a result, we found that the dynamic adhesion force of 1mm radius slider is slightly larger than the static meniscus force (4πRγ), while that of 2mm radius slider is slightly smaller than the static meniscus force, probably because of insufficient formation of meniscus bridge. We also found that contact force is estimated by Hertzian contact theory.

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We experimentally and analytically investigated bouncing vibrations of a flying head slider in near-contact regime. In the experiment, we examined the effect of pitch angle on the unstable vibration with hysteresis between touch-down and take-off process by changing the ambient pressure. The pitch angle of the slider was changed by Z-height. As a result, we found that the hysteresis of touch-down and take-off pressure become small as the pitch angle increase even though the trailing spacing decreases slightly. Next, we measured the slider dynamics at the threshold of the bouncing vibration, and found that there are two cases in the start of unstable bouncing vibration of the slider depending on ZH. Moreover, we measured the 3-dimensional slider motion by using two laser Doppler vibrometers simultaneously, and found that the bouncing vibration is a coupled vibration between translation and pitch with a small phase shift. In the analysis, we used a two-degrees-of-freedom slider model considering attractive force and shearing force of the lubricant. The analytical results agree well with the experimental ones.

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We have proposed a new Dynamic Absorber Suspension (DAS) and showed a significant effect of the dynamic absorber to suppress the flow-induced sway mode and 2^<nd> torsion mode of head suspension by FEM. In this paper, we redesigned the DAS for practical use. From frequency response function of DAS, we found that magnification factor of sway mode can be reduced to 14dB, and that of 2^<nd> torsion mode is 5dB. Next, we fabricated the DAS based on the analytical result to verify the suppression effect of DAS and measured the frequency response function of a fabricated DAS by changing the damping effect and evaluate DAS design. As a result, we found that the newly developed DAS has remarkable damping effect on the sway mode and 2^<nd> torsion mode.

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