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We designed and fabricated multilayered relaxor ferroelectric poly(vinylidene fluoride-trifluoroethylene-clorotrifluoroethylene) [P(VDF-TrFE-CTFE)] actuators in this study. To minimize the driving voltage of the P(VDF-TrFE-CTFE) actuator, which produces bending deformation, we designed a multilayered structure and analyzed the structure using composite beam theory. We developed a new adhesion-mediated film transfer technique to fabricate 1.5 μm-thick P(VDF-TrFE-CTFE) films and laminate them onto a micromachined silicon substrate. Metal electrodes were deposited on top of each P(VDF-TrFE-CTFE) film to obtain a multilayer structure with alternating electrodes. We show that with an applied voltage of only 40 V, the multilayered P(VDF-TrFE-CTFE) actuators fabricated in this study produced deflections of about 9 μm, and their transient behavior faded out within 10 ms. When the actuators were integrated onto a varifocal liquid-filled microlens, an optical power change of more than 50 diopters was obtained. This is the first report of a method to fabricate and stack 1–2 μm-thick PVDF-based films.

An eco-friendly, alternative energy source is a key topic in all engineering fields. In the ship industry, wing-sail technology is drawing great attention as a new type of propulsion that takes full advantage of free wind energy. The purpose of our study is to numerically analyze the aerodynamic characteristics of wing-sails and optimize their shape and operation conditions in terms of the angle of attack, flap length, and deflection angle under various wind directions. A viscous Navier-Stokes flow solver is used for the numerical aerodynamic analysis. A design optimization framework using an evolutionary algorithm and the Kriging surrogate model is developed and finds the optimum operation condition for multiple wing-sails to maximize the resultant propulsive force. First, the exact response surfaces of Cl and Cd are created for a single wing-sail, and a simple trade-off study is conducted to investigate the flap effects in terms of its deflection angle and flap length. Next, the proposed design optimization framework is applied to find the optimum shape and operating conditions for multiple wing-sails, which have three identical wing-sails in a row. A total of nine design variables are employed, including the angle of attack, flap length and deflection angle for each wing-sail, and relative wind direction, which is allowed to vary from 45° to 90° and 135°. Although the design is carried out using a two-dimensional topology, mostly because of the high computational cost related to the nature of gradientfree optimization algorithms, the design results are validated using a high-fidelity threedimensional Computational Fluid Dynamics analysis. Predicted improvement in twodimensional analysis of the averaged thrust by 14~22% of the baseline values turned out to be slightly lower and becomes 10~17% in full three-dimensional flow analysis. Although an initial set of the angle of attack values is varied from 8° to 9.5° to investigate the effects of the initial angle of attack, the trends of the design optimization are preserved. In summary, multiple wing-sails can enhance a ship’s propulsion system by more than 10%.

20 Mega-Hertz-switching high speed image shutter device for 3D image capturing and its application to system prototype are presented. For 3D image capturing, the system utilizes Time-of-Flight (TOF) principle by means of 20MHz high-speed micro-optical image modulator, so called 'optical shutter'. The high speed image modulation is obtained using the electro-optic operation of the multi-layer stacked structure having diffractive mirrors and optical resonance cavity which maximizes the magnitude of optical modulation. The optical shutter device is specially designed and fabricated realizing low resistance-capacitance cell structures having small RC-time constant. The optical shutter is positioned in front of a standard high resolution CMOS image sensor and modulates the IR image reflected from the object to capture a depth image. Suggested novel optical shutter device enables capturing of a full HD depth image with depth accuracy of mm-scale, which is the largest depth image resolution among the-state-of-the-arts, which have been limited up to VGA. The 3D camera prototype realizes color/depth concurrent sensing optical architecture to capture 14Mp color and full HD depth images, simultaneously. The resulting high definition color/depth image and its capturing device have crucial impact on 3D business eco-system in IT industry especially as 3D image sensing means in the fields of 3D camera, gesture recognition, user interface, and 3D display. This paper presents MEMS-based optical shutter design, fabrication, characterization, 3D camera system prototype and image test results.

We designed, fabricated, and characterized varifocal microlenses, whose focal length varies along with the deformation of a transparent elastomer membrane under hydraulic pressure tailored by electroactive polymer actuators. The microfluidic channel of the microlens was designed to be embedded between silicon and glass so that transient fluctuation of the optical fluid and elastomer membrane is effectively suppressed, and thus the microlens is optically stabilized in a reduced time. Multilayered poly(vinylidene fluoride-trifluoroethylene-clorotrifluoroethylene) actuators were also developed and integrated onto the microfluidic chambers. We demonstrated that the developed microlenses are suitable for use in microimaging systems to make their foci tunable.

In this study we developed a liquid-filled varifocal lens operated by electroactive polymer actuators. A silicon wafer was structured with micromachining processes to have four microfluidic chambers and a circular hole working as an aperture. The structured silicon wafer (opaque frame) was bonded to a glass wafer (transparent frame), and thus microfluidic channels were formed between them. Top surface of the main frame was covered with a transparent elastomer membrane, and the internal volume confined by the membrane and the two frames was filled with optical fluid. In order to operate this varifocal lens system, multilayered P(VDF-TrFE-CFE) [poly(vinylidene fluoride-trifluoroethylene-clorofluoroethylene)] polymer actuators were also developed, which show relaxor ferroelectric behavior, and thus produce large electrostrictive strain. When an electric field is applied, the multilayered P(VDF-TrFE-CFE) polymer actuators push the optical fluid so that the elastomer membrane together with the internal fluid changes their shape, which alters the light path of the varifocal lens. The original shape of the elastomer membrane is restored by the elastic recovery of the P(VDF-TrFE-CFE) actuators when an applied electric field is removed. We observed that with the applied voltage of 40 V the varifocal lens changes the optical power of more than 30 diopters within 20 ms. Optical analysis showed that the deformation shape of the optical membrane can be successfully used to design phone camera modules with auto-focus function.

In this paper, the authors present the newly developed high Q film bulk acoustic resonator (FBAR) which has the piezoelectric AlN film sandwiched between two electrode films and mesa-shaped membrane structure by utilizing poly-Si and XeF2 as a sacrificial layer and dry release gas, respectively. By controlling the etching profile of bottom electrode and sacrificial layer, the poor formation of AlN in the edge region of mesa-shaped membrane could be eliminated. In addition, by reducing the parasitic overlap which both of the electrodes and the piezoelectric layer resides directly on the substrate, the authors improve the characteristics of resonator and filter. When we compare with the typical surface micromachined FBAR, such as resonator having its own Bragg reflector or cavity, we could greatly reduce the needs for tight control of chemical mechanical polishing (CMP) of the layer underneath the resonator. The measured Q value and effective electromechanical coupling coefficient of the resonator with the area of 120times120 mum2 were 1450 and 6.43%. The peak insertion loss (IL) and bandwidth of filter were 0.60 dB and 70 MHz, respectively

Unidirectional characteristics of two-level split finger transducers are calculated as functions of the structure parameters, for several electrode materials (Al, Cu, Au etc.) on ST-X quartz, by using a method based on boundary integral equations for the grating structure. The calculation results show that the two-level structures have sufficiently large reflectivity by choosing the electrode materials and modifying the structure parameters. Moreover, 190 MHz range two-level structure filters are fabricated by using high accurate mask alignment techniques with a position error of 50nm. The experiments show a good agreement with the calculations. It is found that the two-level split finger transducers have a larger transduction coefficient and a high reflectivity, compared with other SPUDTs such as a distributed acoustic reflection transducer (DART) or an electrode width control (EWC) SPUDT. It is therefore possible to reduce an insertion loss of the SPUDT filters.

Publisher Summary This chapter proposes a new method for construction of a fiber-reinforced plastic (FRP) ship. In the method, hull shape is defined only by the line elements, and conventional molds for FRP construction method are not used. A 1/3 scale and a full scale mock-ups of a bow portion is manufactured on a proposed pin jig production system to identify and solve the difficulties for practical use. The plates are linked together to complete the hull shape and additional laminas are stacked inside until necessary thickness is obtained. To verify the proposed method and identify the possible flaws, a 1/3 scale model is constructed on the adjustable mold. The hull surface is divided into several pieces and developed onto a plane surface. Hull form of a typical planing boat can be easily modified into a set of developable surfaces with minor modification. It is found that the new production procedure can be successfully applied to the construction of planning vessels made of FRPs. The shape of a developable hull can be represented by line elements placed along the ruling lines and supported by pin jigs attached on the precision bed. It is possible that the system can be used as an adjustable mold for deformation of plane plate to form a hull shape, if the number and rigidity of the elements are enough.

A 20-MHz switching high-speed light-modulating device for three-dimensional (3-D) image capturing and its system prototype are presented. For 3-D image capturing, the system utilizes a time-of-flight (TOF) principle by means of a 20-MHz high-speed micromachined electro-absorptive modulator, the so-called optical shutter. The high-speed modulation is obtained by utilizing the electro-absorption mechanism of the multilayer structure, which has an optical resonance cavity and light-absorption epilayers grown by metal organic chemical vapor deposition process. The optical shutter device is specially designed to have small resistor–capacitor–time constant to get the high-speed modulation. The optical shutter is positioned in front of a standard high-resolution complementary metal oxide semiconductor image sensor. The optical shutter modulates the incoming infrared image to acquire the depth image. The suggested novel optical shutter device enables capturing of a full high resolution-depth image, which has been limited to video graphics array (VGA) by previous depth-capturing technologies. The suggested 3-D image sensing device can have a crucial impact on 3-D–related business such as 3-D cameras, gesture recognition, user interfaces, and 3-D displays. This paper presents micro-opto-electro-mechanical systems-based optical shutter design, fabrication, characterization, 3-D camera system prototype, and image evaluation.

Disclosed herein is an FBAR based duplexer device and a manufacturing method thereof, which can achieve miniaturization, and reduction of a manufacturing cost and enhancement of a yield due to a simplified process. According to the present invention, first, a plurality of FBAR chips are prepared. Each of the FBAR chips comprises a substrate, air gaps and piezoelectric layer unit, which are successively arranged, a plurality of electrode pads electrically connected to the piezoelectric layer unit, and bump balls formed on the electrode pads in a one to one ratio. Then, a duplexer substrate having a duplexing circuit is prepared, and a plurality of the FBAR chips come into contact with the duplexer substrate. In this state, they are reversed so that the substrates of the FBAR chips face upward, and the bump balls are bonded to the duplexer substrate. After that, protective structures are formed by the use of a film, so as to be positioned on side surfaces as well as upper surface of the respective FBAR chips, and finally, a molding portion is formed so as to cover the protective structures.