Session: 4G INDUSTRIAL MEASUREMENTS AND APPLICATIONS Chair: J. Tsujino Kanagawa University. 4G-1 4:30 p.m.

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1 Session: 4G INDUSTRIAL MEASUREMENTS AND APPLICATIONS Chair: J. Tsujino Kanagawa University 4G-1 4:30 p.m. DUAL-MODE LONGITUDINAL-SHEAR TRANSDUCER BASED ON STACKED PIEZOELECTRIC ELEMENTS P. H. JOHNSTON*, NASA Langley Research Center. Corresponding Stacks of longitudinally polarized piezoelectric elements with alternating polarity have long been used to achieve high acoustic outputs, such as in lithotripter transducers. Crystals exhibiting a shear piezoelectric response can also be stacked in this manner, and the alignment of their shear axes is a strong factor in their behavior. For crystals whose piezoelectric response includes both longitudinal and shear, the two orthogonal modes can be considered to exist within separate virtual crystals which are electrically in parallel (common electrodes) but mechanically uncoupled (orthogonal modes). The goal of this research is development of multi-mode transducers, which can detect and separate longitudinal and shear modes by exploiting this electromechanical behavior. Transducers were constructed using stacks of lithium niobate crystals having three different cuts: 36 Y-cut (having 4 MHz longitudinal resonance), 41 X-cut (having 2.5 MHz shear resonance), and 10 Y-cut (having both 4.15 MHz longitudinal and 2.5 MHz shear resonances). Single-mode stacks were constructed using pairs of 36 Y-cut and of 41 X-cut crystals with their polarizations anti-parallel. To achieve dual-mode, 10 Y-cut crystals were stacked with their longitudinal polarizations anti-parallel, and their shear polarizations parallel. When the resulting transducers were excited by longitudinal and shear incident modes, the electrical responses from the separate crystals were found to exhibit in-phase and out-of-phase nature according to their relative polarizations. These results suggest that these signals might be combined to separate longitudinal and shear modes incident simultaneously on the transducer. 4G-2 4:45 p.m. ULTRASONIC DETERMINATION OF PHYSICAL PROPERTIES OF THE FIBRE MATERIAL IN DILUTE PULP FIBRE SUSPENSIONS T. LOFQVIST* and Y. COLOMBI, EISLAB, Dept. of Comp. Sci. and Elec. Eng., Lulea University of Technology, SE Lulea, Sweden. Corresponding tlt@sm.luth.se This study concerns the determination of the physical properties of the fibre material of fibres suspended in a liquid using ultrasound. This has been studied 317

2 earlier but these studies have generally been constricted to spherical particles in suspension or droplets in an emulsion. The attenuation of ultrasound is described using a model derived from first principles based on single scattering of ultrasound from the fibres. The derivation follows similar lines to those developed by Habeger [1]. The fibres are considered to be non-interacting, randomly oriented, infinitely long, straight, isotropic, viscoelastic, circular cylinders of equal diameter. Unlike Habeger, ultrasonic attenuation due to viscosity and thermal processes are neglected. The proposed model is a function of the frequency of the ultrasound, the physical properties of the suspending fluid as well as physical properties of the fibre material, e.g. fibre density and speed of sound in the fibre material, which is connected to the fibre modulus of elasticity. Experimental results are obtained from ultrasonic measurements of the attenuation in pulp fibre suspensions. By performing a non-linear least squares fitting procedure, the model parameters are fitted to experimental data on ultrasonic attenuation for a fibre suspension, thus yielding experimental values for fibre density and fibre elasticity modulus. The proposed method is particularly useful as the existing methods are based on testing fibres individually. The problem studied is relevant both from scientific and from industrial viewpoint. [1] Habeger C.C., The attenuation of ultrasound in dilute polymeric fiber suspensions, J. Acoust. Soc. Am., 72(3) G-3 5:00 p.m. MULTI SENSOR SUITE COMPRISING ACTIVE AND PASSIVE ULTRASONIC TRANSDUCERS FOR MONITORING SOLIDS FLOW AND SILO INTEGRITY U. DATTA 2,S.OSE 2, M. HALSTENSEN 1, and S. MYLVAGANAM* 1, 1 Telemark University College, 2 Tel-Tek. Corresponding saba.mylvaganam@hit.no The bulk solid flow in silos and monitoring silo integrity are still challenging problems in the field of powder science and technology. The types of flow in silos have to be identified as early as possible to remedy problems associated with rat-hole, arching and plug flow to facilitate the preferred mode of mass flow. Acoustic techniques have been used to solve some of these problems with some success in the recent past. By incorporating passive ultrasonic sensors mostly in the form of acoustic emission sensors, in addition to active ones used in interrogating surface and flow of solids in silos, silo inlets and outlets, it has been shown that the solids flow in silos can be identified without interrupting the process thus leading to improved process monitoring and control in the storing, transport and handling of bulk solids. A sensor suite comprising multiple passive and active ultrasonic sensors have been used successfully in achieving the following in a pilot plant consisting of silos with multiple hoppers and associated transport facilities: identification of solids flow type, identification of particulate material from signature signals from passive sensors, solids flow rate, slip velocity and assessing silo integrity. Assessing silo integrity is important in large scale 318

3 silos in avoiding catastrophic accidents in plants dealing with bulk solids. The sensor data fusion is done in both frequency and time domains using some artificial intelligent technologies involving multivariate data analysis and neural networks. Some results will be shown online during the conference involving six active and six passive ultrasonic sensors. Part of this work is sponsored by the Royal Norwegian Research Council. Part of the PLC based AE sensor system was financed by the EU thematic network THEIERE. The experience of and input from the POSTEC members have been useful in realising the system integration. 4G-4 5:15 p.m. HIGH TEMPERATURE ULTRASONIC TRANSDUCERS FOR MONITORING OF MICRO-MOLDING M. KOBAYASHI* 1, C.-K. JEN 2,C.CORBEIL 2,Y.ONO 2, H. HEBERT 2,andA. DERDOURI 2, 1 McGill University, 2 IMI, National Research Council of Canada. Corresponding cheng-kuei.jen@cnrc-nrc.gc.ca Miniaturization continues to be the demanding trend in the field of mass production of low-cost micro and nano-systems. For miniaturized devices, micromolding of polymeric materials becomes one of the alternatives to replace the present expensive serial fabrication methods associated with silicon substrates. The micro-molding process has the ability to mold micro-channels with an extreme precision that is a key to fabricate disposable, miniature and diagnostic lab-on-a-chip devices. However, polymers will need to be selected and modified in order to meet the requirements of narrow process windows involved with their flow, solidification and microstructure development in micron size channels. Because of this complexity on-line process monitoring is requested to improve the quality of the molded part and optimize the process. Ultrasonic method is chosen because of its ability to probe the properties of polymers within the mold during micromolding process. The preferred requirements of ultrasonic transducers (UTs) for in-line monitoring of the micro-molding are that UTs (1) are applicable at temperatures higher than 200 C, (2) are miniature, (3) can be coated on curved surfaces, (4) do not need couplant, (5) can be operated in low and medium MHz frequency range and (6) have sufficient piezoelectric strength. We have used fine bismuth titanate (BIT) powders mixed with lead-zirconate-titanate (PZT) gel and fabricated BIT/PZT thick film UTs by a sol-gel spray technique. They have been operated up to 440 C, have a thickness less than 100µm andadiameter less than 6 mm, have been deposited onto steel tubes of diameters less than 12.7 mm diameter, have no need of couplant, have a center frequency between 5 and 20 MHz and a signal to noise ratio of more than 30 db at the steel mold-air interface. Our top electrode is made of silver paste, which can operate at a temperature higher than 350 C. Films are poled using corona discharging technique. Ultrasonic experiments have been carried out on barrels and mold inserts, which are replica to components of a Micro-System 50 from Battenfeld. The ability of these UTs to monitor the micromolding processing parameters and polymer properties will be demonstrated. Financial support of NSERC and NRC-NSC, Taiwan project is acknowledged. 319

4 4G-5 5:30 p.m. HIGH FREQUENCY COMPLEX VIBRATION SYSTEMS USING A COMPLEX VIBRATION CONVERTER WITH DIAGONAL SLITS J. TSUJINO*, S. IHARA, Y. HARADA, K. KASAHARA, and N. SAKAMAKI, Kanagawa University. Corresponding tsujino@cc.kanagawa-u.ac.jp High frequency complex vibration systems of 129 khz and 180 khz are studied. The vibration system consists of a longitudinal vibration transducer with two 20-mm-diameter and 5-mm-thick piezo-ceramic rings, a stepped horn for amplifying vibration velocity (transform ratio N = 4) with a supporting flange and a complex vibration converter of 11 mm diameter with diagonal slits that has four 2 mm to 4 mm square welding tips at the free edge. A transverse vibration tip with 2- to 4-mm-diameter can be installed in the free edge of the complex vibration converter. The complex vibration converter is made of stainless steel or titanium alloy and has ten narrow diagonal slits cut by an electric sparking machine in the circumference of the converter. The slit size is 0.5 mm in width, 7 mm in length, 1.5 mm in depth and 45 in direction. Vibration locus at the free edge of the converter is elliptical to circular. Quality factors of these vibration systems are more than 765. Using the complex vibration welding system, mm-diameter polyurethane coated insulated copper wire can be weld directly on the various substrates with the weld strength almost equal to the wire strength of 40 gf. Deformation of the welded wire is about 50%. Insulated thin wires with various plastic coatings are used for various applications in electronics and furthermore in microelectronics as examples, direct joining of installed antenna wires of various wireless remote cards and insulated voice coil wire of a loudspeaker, etc. Coated wires are impossible to weld using a conventional ultrasonic welding equipment with linear vibration locus. The welded specimens were inspected using a tensile strength tester, a height gage, SEM and a laser microscope. The copper wire part is completely welded on the copper substrate. The complex vibration systems are effectively applicable to wire bonding using a transverse vibration tip, and flip-tip bonding of 2 mm to 4 mm square semiconductor tips with many bumps that are must to connect simultaneously, saw devices and various electronic devices directly on the substrate or ceramic cases without solder. This work was supported by a Grant-in-Aid for Scientific Research (A) from the Ministry of Education, Culture, Sport, Science and Technology in Japan. 320

5 4G-6 5:45 p.m. CONFIGURATION OF A 30-MM-DIAMETER 94 KHZ ULTRASONIC LONGITUDINAL VIBRATION SYSTEM FOR PLASTIC WELDING J. TSUJINO*, M. HOGOH, M. YOSHIKUNI, H. HASHII, and T. UEOKA, Kanagawa University. Corresponding tsujino@cc.kanagawa-u.ac.jp Vibration and welding characteristics of a 30-mm- diameter 94 khz ultrasonic plastic welding system are studied. The 94 khz ultrasonic plastic welding system consists of a 30 mm-diameter bolt- clamped Langevin type piezo-ceramic (PZT) longitudinal transducer, a stepped horn (vibration velocity transform ratio N=3.0) with a supporting flange at a nodal position and a catenoidal horn (N=3.13) with a 8-mm-diameter welding tip. Total vibration transform ratio is The vibration rod diameter of 30 mm is corresponding to 0.56 wavelength of longitudinal velocity that is larger than the conventional design criteria length that is under 1/4 wavelength to avoid radial resonance vibration. The 30-mmdiameter of PZT ring is corresponding to 0.95 wavelength that is less than 1 wavelength. The vibration system is made of high strength supper aluminum alloy (JISA7075B) to increase maximum vibration velocity. Radial vibration amplitude measured using a laser Doppler vibrometer around the welding tip is 1/50 of longitudinal vibration amplitude of the welding tip surface. The 94 khz longitudinal vibration system is simple compared with the 90 khz system that was made formally using six 15- mm-diameter bolt-clamped Langevin type (PZT) longitudinal transducers installed in a radial to longitudinal vibration direction converter. Maximum vibration velocity of the welding is 3.3 m/s (peak-to-zero value) and quality factor is about Welding characteristics of 1.0-mm-thick polyurethane sheet specimens using 94 khz, 67 khz, 40 khz and 27 khz welding systems with an 8- mm-diameter welding tip are compared. Required vibration velocity decreases as vibration frequency increases. Using the 94 khz welding system, weld strength more than 580 N per one welded area of 8 mm diameter were obtained and the weld strength per welded area was 12 MPa. This vibration system is effective for the other various applications. Session: 5G SAW SIMULATION Chair: V. Plessky GVR Trade SA 5G-1 4:30 p.m. A GENERALIZED P-MATRIX MODEL FOR SAW FILTERS G. KOVACS*, EPCOS AG. Corresponding Guenter.Kovacs@epcos.com 321