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Abstract 59 | Electric Motor | Nanowire

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SPECIAL PURPOSE MACHINES D.VENKATESH L6EE924 EMAIL: venkey_048@yahoo.co.in Phone: 9963510494 G.MADAN Y5EE840 EMAIL:gmadan87@yahoo.co.in Phone: 9963510494 R.V.R & J.C.COLLEGE OF ENGINEERING Chandramoulipuram Chowdavram GUNTUR - 19 ABSTRACT: Day by day the interest on special machines increases. Because these machines serves for several nano Nano generator Researchers have demonstrated a prototype nanometerscale generator that produces continuous direct-current electricity by harvesting mech
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    SPECIAL PURPOSE MACHINES D.VENKATESH G.MADAN   L6EE924 Y5EE840EMAIL: venkey_048@yahoo.co.in EMAIL:gmadan87@yahoo.co.inPhone: 9963510494 Phone: 9963510494  R.V.R & J.C.COLLEGE OF ENGINEERING   ChandramoulipuramChowdavram GUNTUR - 19    2  ABSTRACT: Day by day the interest onspecial machines increases. Becausethese machines serves for severalapplications.For instance,the nanogenerator could drive biological sensors by making use of wind energy or water flow,eliminating the need for external batteries.This not only reduces thedevice cost but also at the same timereduces the entire equipment size.Integrated starter generator which is used in electric vehicles acts asa bidirectional energy converter as amotor when powered by the battery or agenerator when driven by theengine.Linear motors are used to propelhigh speed MagLev trains.Micro motors plays an important role in computer harddrives,optics,sensors and actuators.Aspecial type of outer rotor motors used todrive the polygonal rotating mirrorswhich are mounted directly on the rotor in laser printers. Our paper tries to introducesome of these machines and theirapplications in various fields.The recentdeveloped technology of nanogenerators is included and its working isalso explained.   Nano generator    Researchers havedemonstrated a prototype nanometer-scale generator that produces continuousdirect-current electricity by harvestingmechanical energy from suchenvironmental sources as ultrasonicwaves, mechanical vibration or bloodflow. The nanogenerators take advantageof the unique coupled piezoelectric andsemiconducting properties of zinc oxidenanostructures, which produce smallelectrical charges.Fabrication begins with growing anarray of vertically-aligned nanowiresapproximately a half-micron apart on  3 gallium arsenide, sapphire or a flexible polymer substrate. A layer of zinc oxideis grown on top of substrate to collectthe current. The researchers alsofabricate silicon “zig-zag” electrodes,which contain thousands of nanometer-scale tips made conductive by a platinumcoating.The electrode is then loweredon top of the nanowire array, leaving justenough space so that a significantnumber of the nanowires are free to flexwithin the gaps created by the tips.Moved by mechanical energy such aswaves or vibration, the nanowires periodically contact the tips, transferringtheir electrical charges. By capturing thetiny amounts of current produced byhundreds of nanowires kept in motion,the generators produce a direct currentoutput in the nano-Ampererange. If wehad a device like this in our shoes whenwe walked, we would be able to generateour own small current to power smallelectronics.Anything that makes thenanowires move within the generator can be used for generating power. Verylittle force is   required to move them. Nano motor  Even smaller motorshave been made using nanotechnology.An example is shown below. It consistsof a tiny gold slab rotor, about 100 nmsquare, mounted on concentric carbonnanotubes.The outer tube carries therotor, driven by electrostatic electrodes,rotating around an inner tube which actsas a supporting shaft. By applyingvoltage pulses of up to 5 Volts betweenthe rotor plate and stators, the position,speed and direction of rotation of therotor can be controlled. It measuresabout 500 nanometers across, 300 timessmaller than the diameter of a humanhair.The motor was built frommultiwalled nanotubes created in anelectric arc and deposited on the flatsilicon oxide surface of a silicon wafer.A rotor, nanotube anchors and opposing  4 stators were then simultaneously patterned in gold around the selectednanotubes using electron beamlithography. A third stator was already buried under the silicon oxide surface.The silicon was then etched to create atrough beneath the rotor with sufficientclearance for the rotor to rotate.Possibleapplications are moveable mirrors for optical switches or paddles for movingfluids. Axial Field Motors Axial field motorshave been developed for applicationswhich require short, flat, pancake construction. Printed Circuit (PCB) or  Pancake Motor: The printed circuitmotor is an example of an ironless or coreless motor with several uniquefeatures. The pancake construction usesan axial magnetic field to achieve theshort flat construction. Radial field PCBmotors are also possible. Construction:   The rotor windings are printed,stamped or welded onto a thin, discshaped glass fibre circuit board whichrotates in the air gap between pairs of  permanent magnets arranged around the periphery of the disk. The windings fanout in a series of radial loops around thesurface of the disk. The magnets arearranged alternatively north and south sothat the magnetic fields in the air gaps of adjacent magnet pairs are in oppositedirections. The magnets are held in place by two iron end caps in a compact pancake shaped block to complete themagnetic circuit. Current is fed to therotor windings via brushes through precious metal commutator segments printed on the disc. Operating Principle:   Traditional electric motorshave a radial magnetic field or flux withthe rotor current flowing axially alongthe length of the rotor. In typical printed
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