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فیلم - کارکرد دستگاه میکرو اسمبلی

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شرکت اینترسونیک با تجربه 50 ساله در طراحی وساخت شوینده های صنعتی و آزمایشگاهی جایگاه موفقی در این صنعت کسب بدست آورده است صادرات به بیش از 15 کشور جهان از جمله کشور های اروپایی همچنین تنوع محصولات گسترده جهت کاربرد های مختلف صنعتی، آزمایشگاهی، پزشکی، الکترونیک ارایه داده است.

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رویداد : 1396/7/1

شرکت ترفند نماینده فیزیک اینسترومنت (PI) آلمان در ایران

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ترفند-تاریخچه شرکت تورلبز (Thorlab)

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تجهیزات اپتیک

شرکت مهندسی ترفند آمادگی دارد کلیه محصولات و تجهیزات اپتیکی از جمله مکانیزم های کنترل حرکت و موقعیت دقیق، تجهیزات اپتومکانیک، آینه های اپتیک، منابع نور اپتیک، سیستم های اپتیکی ایزوله و میزهای اپتیکی ضد ارتعاش با برند معتبر NewPort را بنا به درخواست شرکت ها،سازمان ها، آزمایشگاه ها صنعتی، تحقیقاتی و آموزشی بصورت مستقیم تامین و وارد نماید.

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رویداد : 1396/07/10

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Fundamentals of Piezo Technology From the Physical Effect to Industrial Use The word "piezo" is derived from the Greek word for pressure. In 1880 Jacques and Pierre Curie discovered that pressure generates electrical charges in a number of crystals such as quartz and tourmaline; they called this phenomenon the "piezoelectric effect". Later they noticed that electrical fields can deform piezoelectric materials. This effect is called the "inverse piezoelectric effect". The industrial breakthrough came with >> Piezoelectric Ceramics, when scientists discovered that barium titanate adopts piezoelectric characteristics on a useful scale when an electric field is applied. The piezoelectric effect is nowadays used in many everyday products such as lighters, loudspeakers and signal transducers. Piezo actuator technology has also gained acceptance in automotive technology, because piezo-controlled injection valves in combustion engines reduce the transition times and significantly improve the smoothness and exhaust gas quality. Direct and Inverse Piezoelectric Effect Pressure generates charges on the surface of piezoelectric materials. This direct piezoelectric effect, also called generator or sensor effect, converts mechanical energy into electrical energy. Vice versa, the inverse piezoelectric effect causes a change in length in this type of materials when an electrical voltage is applied. This actuator effect converts electrical energy into mechanical energy. The piezoelectric effect occurs both in monocrystalline materials and in polycrystalline ferroelectric ceramics. In single crystals, an asymmetry in the structure of the unit cells of the crystal lattice, i.e. a polar axis that forms below the Curie temperature TC , is a sufficient prerequisite for the effect to occur. Piezoelectric ceramics additionally have a spontaneous polarization, i.e. the positive and negative charge concentration of the unit cells are separate from each other. At the same time, the axis of the unit cell extends in the direction of the spontaneous polarization and a spontaneous strain occurs. Piezoelectric Ceramics ... The piezoelectric effect of natural monocrystalline materials such as quartz, tourmaline and Rochelle salt is relatively small. Polycrystalline ferroelectric ceramics such as barium titanate (BaTiO3) and lead zirconate titanate (PZT) exhibit larger displacements or induce larger electric voltages. PZT piezo ceramic materials are available in many variations and are most widely used for actuator or sensor applications. Special dopings of the PZT ceramics with e.g. Ni, Bi, La, Nd, Nb ions make it possible to specifically optimize piezoelectric and dielectric parameters. … with Polycrystalline Structure At temperatures below the Curie temperature TC , the lattice structure of the PZT crystallites becomes distorted and asymmetric. This brings about the formation of dipoles and the rhombohedral and tetragonal crystallite phases, which are of interest for piezo technology. The ceramic exhibits spontaneous polarization. Above the Curie temperature the piezoceramic material loses its piezoelectric properties. Polarized domains (Image: IKTS Dresden) Ferroelectric Polarization To minimize the internal energy of the material, ferroelectric domains form in the crystallites of the ceramic. Within these volumes, the orientations of the spontaneous polarization are the same. The different orientations of bordering domains are separated by domain walls. A ferroelectric polarization process is required to make the ceramic macroscopically piezoelectric as well. For this purpose, a strong electric field of several kV/mm is applied to create an asymmetry in the previously unorganized ceramic compound. The electric field causes a reorientation of the spontaneous polarization. At the same time, domains with a favorable orientation to the polarity field direction grow and those with an unfavorable orientation shrink. The domain walls are shifted in the crystal lattice. After polarization, most of the reorientations are preserved even without the application of an electric field. However, a small number of the domain walls are shifted back to their original position, e.g. due to internal mechanical stresses. Principle of the ferroelectric polarization Expansion of the Polarized Piezo Ceramic The ceramic expands, whenever an electric field is applied, that is less strong than the original polarization field strength. Part of this effect is due to the piezoelectric shift of the ions in the crystal lattice and is called the intrinsic effect. The extrinsic effect is based on a reversible ferroelectric reorientation of the unit cells. It increases with increasing strength of the driving field strength and is responsible for most of the nonlinear hysteresis and drift characteristics of ferroelectric piezoceramics. Displacement of ferroelectric piezo ceramics at different control amplitudes ... Electromechanics Polarized piezoelectric materials are characterized by several coefficients and relationships. In simplified form, the basic relationships between the electrical and elastic properties can be represented as follows: D Electric flux density T Mechanical stress E Electrical field S Mechanical strain d Piezoelectric charge coefficient ?T Permittivity (for T = constant) sE Compliance or elasticity coefficient (for E = constant) These relationships apply only to small electrical and mechanical amplitudes, so-called small signal values. In this range, the relationships between mechanical, elastic deformation S or stress T and electrical field E or electrical flux density D are linear, and the values for the coefficients are constant. These small-signal coefficients can be found in the material data table: Assignment of Axes The directions are designated by the axes 1, 2 and 3 (corresponding to the axes X, Y and Z of the Cartesian coordinate system). The rotational axes, known as U, V, W in the coordinate system, are designated with 4, 5 and 6. The direction of polarization (axis 3) is established during the polarization process by means of a strong electrical field applied between the two electrodes. This is where the largest displacement of the piezoceramic is reached. Since the piezoelectric material is anisotropic, the corresponding physical quantities are described by tensors. The piezoelectric coefficients are therefore indexed accordingly. Orthogonal system to describe the properties of a polarized piezo ceramic. Axis 3 is the direction of polarization Piezoelectric Coefficients Permittivity ? The permittivity ? or the relative dielectric coefficient DC is the ratio of the absolute permittivity of the ceramic material and the permittivity in vacuum (?0 = 8.85 × 10-12 F/m), where the absolute permittivity is a measure of the polarizability in the electrical field. The dependency of the dielectric coefficient from the orientation of the electric field and the dielectric displacement is symbolized by the corresponding indices. Examples: ?33T DCvalue in the polarization direction when an electric field is applied in the direction of polarization (direction 3) at a constant mechanical stress (T=0: "free" permittivity) ?11S Electrical field and dielectric displacement in the direction of axis 1, at constant deformation (S=0: "clamped" permittivity) Piezoelectric charge coefficient, piezoelectric deformation coefficient, piezo modulus dij The piezo modulus is the ratio of induced electric charge to mechanical stress or of achievable mechanical stress to electric field applied (T = constant). For piezo actuators, the piezo modules is also referred to as deformation coefficient. Example: d33 Strain produced per unit of applied electrical field in V/m or charge density in C/m2 per unit of pressure in N/m2, each in the polarization direction Piezoelectric Voltage Coefficient gij The piezoelectric voltage coefficient g is the ratio of the electric field strength E to the effective mechanical stress T. Dividing the respective piezoelectric charge coefficient dij by the corresponding permittivity gives the corresponding gijcoefficient. Example: g31 Induced electric field in direction 3 per unit mechanical stress acting in direction 1 = force per unit area, not necessarily orthogonal d(GS) for various materials and control modes Elastic Compliance sij The elastic compliance coefficient s is the ratio of the relative deformation S to the mechanical stress T. Mechanical and electrical energy are mutually dependent, which is why the electrical boundary conditions such as the electric flux density D and field strength E must be taken into consideration. Examples s33E Ratio of the mechanical strain in direction 3 to the mechanical stress in direction 3, at constant electric field (for E = 0: short circuit) s55E the ratio of a shear strain to the effective shear stress at constant dielectric displacement (for D = 0: no load). The frequently used elasticity or Youngs modulus Yij corresponds in a first approximation to the reciprocal value of the corresponding elasticity coefficients. Frequency Coefficient Ni The frequency coefficient N describes the relationship between the geometrical dimension A of a body and the corresponding (series) resonant frequency. The indices designate the corresponding direction of oscillation, A = dimension, N = fS × A ). Examples: N3 Frequency coefficient for the longitudinal oscillation of a slim rod, polarized in longitudinal direction N1 Frequency coefficient for the transverse oscillation of a slim rod, polarized in direction 3 N5 Frequency coefficient of the thickness oscillation of a thin plate NP Frequency coefficient of the planar surface oscillation of a round disk Nt Frequency coefficient of the thickness oscillation of a thin plate polarized in the thickness direction Mechanical Quality Factor Qm The mechanical quality factor Qm characterizes the "sharpness of resonance" of a piezoelectric body or resonator and is primarily determined from the 3 dB bandwidth of the series resonance of the system which is able to oscillate. The reciprocal value of the mechanical quality factor is the mechanical loss factor, the ratio of effective resistance to reactance in the equivalent circuit diagram of a piezoelectric resonator at resonance. Coupling Factors k The coupling factor k is a measure of the extent of the piezoelectric effect (not an efficiency factor!). It describes the ability of a piezoelectric material to convert electrical energy into mechanical energy and vice versa. The coupling factor is determined by the square root of the ratio of stored mechanical energy to the total energy absorbed. At resonance, k is a function of the corresponding form of oscillation of the piezoelectric body. Examples: k33 Coupling factor for longitudinal oscillation k31 Coupling factor for transverse oscillation kP Coupling factor for radial oscillation (planar) of a round disk kt Coupling factor for the thickness oscillation of a plate k15 Coupling factor for the thickness shear oscillation of a plate Dynamic Behavior The electromechanical behavior of a piezoelectric body excited to oscillations can be represented by an electrical equivalent circuit diagram. C0 is the capacitance of the dielectric. The series circuit, consisting of C1, L1, and R1, describes the change in the mechanical properties, such as elastic deformation, effective mass (inertia) and mechanical losses resulting from internal friction. This description of the oscillatory circuit can, however, only be used for frequencies in the vicinity of the mechanical intrinsic resonance. Most piezoelectric material parameters are determined by means of impedance measurements on special test bodies at resonance. The series and parallel resonances are used to determine the piezoelectric parameters. These correspond to a good approximation of the impedance minimum fm and maximum fn. Typical impedance curve Equivalent circuit diagram of a piezoelectric resonator Oscillation States of Piezoceramic Components Oscillation states or modes and the deformation are decided by the geometry of the body, the mechano-elastic properties and the orientations of the electric field and the polarization. Thorlabs Inc., in Newton, N.J., began more than 18 years ago in Alex Cable’s basement with a one-page catalog and a handful of optomechanical products that Alex had designed and machined. Today, its catalog offers more than 17,000 products. Still privately held, Thorlabs is now a global photonics supplier with seven manufacturing facilities located in five countries. Alex attributes the company’s success to its openness to change and its nimble response to it. “Our strong growth has always provided for a new set of opportunities just over the horizon,” he said. “What I love is having a different business to run every 18 months or so, and the photonics industry continues to provide these new challenges.” In the 1980s, Alex worked at AT&T Bell Labs under Steve Chu, who went on to win the Nobel Prize in physics in 1997. The researchers built a first-generation prototype in which the coarse stage had a stroke of a few millimeters, a micrometer step size, and a 1.5 mm/s speed. The fine piezo stage had a control bandwidth of about 10 kHz. A fiber-optic interferometer with three interference signals was used for compactness—while the interferometer had a large drift of 70 nm over 1000 s, improvements will reduce this to 10 nm over the same time span. The 150 × 150 ?m electrostatically actuated MEMS device, which was 2 ?m thick and made of silicon carbide, included a 40 × 40 ?m optical element (a transparent window) integrated with the MEMS structure during manufacture of the MEMS device. In future systems, the transparent window would be replaced by the optics of choice. A second-generation experimental device was built in which the functions of the coarse and piezo stages were combined, reducing the length and the moving mass of the instrument. Initial tests of one of the three actuators for the combined stage showed a step size of 0.32 ?m, which at a 10 kHz drive rate results in a speed of 3.2 mm/s. The second-generation meta-instrument has a 158 mm2 footprint, which means that 450 of these instruments could be packed together to simultaneously examine 450 sites on a 300 mm semiconductor wafer. Because the embedded interferometer system itself cannot measure the distance from the lens surface to the sample, no system-wide data can yet be gathered in these devices. The addition of a sample-sensing system either next to or integrated into the optical element, or the addition of a point-probe stylus, will lead to a fully developed meta-instrument. REFERENCE 1. R. J. F. Bijster et al., arXiv:1608.04281v1 [physics.ins-det] (Aug. 15, 2016). As would any optics positioning and focusing system, the meta-instrument must keep the optical element at the proper distance from the sample, even as the optics are scanned across the samples varied topography. Most importantly, it must do this with enough precision to avoid contact with the sample. In addition, it has a tip-tilt function that is operative even during scanning. For the optics that will be positioned by the meta-instrument, a typical field of view is on the order of 10 × 10 ?m (with a total optical element size on the order of 1 × 1 mm), leading to a 1 ?rad or better tip-tilt precision requirement. The desired lateral scan speed of at least 1 mm/s leads to the 100 kHz required bandwidth for the focusing system. Optics integrated into MEMS stage The meta-instrument is a combination of three positioning stages: a three-actuator coarse stage (producing translation plus tip-tilt) and a three-actuator fine piezo stage, the combination of which is monitored position-wise by three interferometers adjacent to the actuators, as well as a high-speed microelectromechanical-systems (MEMS) stage on which, for example, a hyperlens could be fabricated in the same process that is used to create the MEMS device (see figure). The motion of the MEMS stage is measured by a capacitive sensor. It is worth mentioning that the fifth Iran made laboratory equipment and chemical exhibition was opened on April 25thby the vice-president in which more than 8700 product models were introduced by 335 companies attending the exhibition. He also added, similar to previous editions of the exhibition, Iranlabexpo 2017 is comprised of 13 specialized sections including oil and petrochemical industries, electrics, electronics and software, civil and construction engineering, mechanics, chemistry and metallurgy, agriculture and environment, physics, general laboratory equipment, laboratory chemicals, biological engineering and biomaterials, industrial testing equipment and calibration services. Iran. The vision is the following: For materialization of the twenty year vision of the Islamic Republic of Iran, the software movement and the improvement of level, quality and security of people’s life, in a ten year period, the Islamic Republic of Iran will be a developed country in terms of nanotechnology with the followin Local advanced infra-structures and enjoying higher share of expert human resources Having effective and constructive internal and international interactions Generator of economic added value resulting from nanotechnology Enjoying competition capability at global level” Determining national priorities, overcoming the obstacles in the program, providing facilities in nano-areas were the INIC main duties. Main goals, strategies and structure of overall-management of nanotechnology development are clearly stated in this plan. Ten years horizon of the future strategy is divided into four periods: In the first 3 year period, 53 programs have been implemented. Based on their evaluation, the second complementary plan for the next three years was provided and approved. In this plan, the programs are categorized into a series of topics covering all wealth creation steps from proposal to market. The private sector role in development of nanotechnology in Iran is highlighted in this plan. Topics are as follows: Policy Making and Evaluation Publicity and increasing Public Awareness Scientific and Technological Infrastructures Scientific and Technological Initiative Technology Transfer and Development Production and Market This plan, including 33 programs, considers international interactions in various approaches. The followings are the most important measures taken by INIC to escalate the international interactions: Enhancement of International Scientific and Technological Collaboration: In the Future Strategy plan, the improvement of scientific and technological collaborations with other countries is encouraged. International sharing of laboratorial services: The INIC encourages international collaboration of nanotechnology laboratories. International sharing of laboratorial services, construction of experimental equipment and development of crucial technologies in collaboration with the developed centers worldwide which are supported by the INIC. Enhancement of international investments in nanotechnology INIC intends to attract more foreign investments in nanotechnology considering domestic advantages such as professional human resources, appropriate infrastructures and sustainable support policies by the government. Supporting agencies to expand international interactions INIC supports national nanotechnology agencies by, for instance, finding international partners, facilitating participation in international fairs and markets and opening new international collaborations with other scientific, technological and industrial centers of nanotechnology. Some of the most important events in the Islamic Republic of Iran