Magnetic Levitation

CSIR-CEERI,Pilani

Introduction. Definition. Principle. Types of magnetic levitation. Types of method. Different Laws. Application. MEMS. VLSI. MOSFET. VHDL.

Contents of magnetic levitation

IntroductionMagnetic levitation is the process of levitating an object by exploiting magnetic fields. In other words, it is overcoming the gravitational force on an object by applying a counteracting magnetic field. Either the magnetic force of repulsion or attraction can be used. In the case of magnetic attraction, the experiment is known as magnetic suspension. Using magnetic repulsion, it becomes magnetic levitation.

Magnetic Levitation

Any thing which may levitate (Raise or Float) by means of magnetic power is simply called as magnetic levitation.

Magnetic Levitation

Magnetic Levitation

Electromagnetic Suspension (EMS) is the magnetic levitation of an object achieved by constantly altering the strength of a magnetic field produced by electromagnets using a feedback loop.

Electrodynamic suspension (EDS) is a form of magnetic levitation in which there are conductors which are exposed to time-varying magnetic fields. This induces eddy currents in the conductors that creates a repulsive magnetic field which holds the two objects apart.

Magnetic Levitation

Repulsion between like poles of permanent magnets. Repulsion between a magnet and a metallic conductor induced by relative motion. Repulsion between a metallic conductor and an AC electromagnet. Repulsion between a magnetic field and a diamagnetic substance. Repulsion between a magnet and a superconductor. Attraction between unlike poles of permanent magnets or electromagnets. Attraction between an electromagnet and a piece of iron or a magnet, with sensors and active control of the current to the electromagnet used to maintain some distance between them. Repulsion between an electromagnet and a magnet with sensors and active control of the current to the electromagnet used to maintain some distance between them.  

Magnetic Levitation

Faraday’s Law

Any change in the magnetic environment of a coil of a wire will cause an emf to be induced in the coil.

Magnetic LevitationLenz’s Law

When an emf is generated in a coil due to changing magnetic flux (according to Faraday’s law), the polarity of the induced emf is such that it produces a current whose magnetic field opposes the change which produces it.

Magnetic Levitation

1. Maglev Trains.2. Floating Cities.3. 3-D Cell Cultures.4. Space launch System.5. Efficient Wind Turbines.6. Magnetic Bearings.7. Studying Weightlessness.8. Flying Cars.

MEMS

MEMS is a technology of very small devices. It is a combination of mechanical functions and electrical functions on the same chip using micro fabrication technology.

MEMS devices generally range in size from 20 micrometers to a millimeter.

MEMS USES

The mems microphone also called as microphone Chip is widely used in the present day communication world.

Micro-electro mechanical system (MEMS) technology help projectiles to reach their targets accurately.

MEMS FABRICATIONThere are three basic building blocks in MEMStechnology.

Deposition: The ability to deposit thin film of material on substrate.

Lithography: To apply a patterned mask on top of the films by photolithographic imaging.

Etching: To etch the films selectively to the mask.

VLSIVery-large-scale integration (VLSI) is the process of creating an integrated circuit (IC) by combining thousands of transistors into a single chip. VLSI began in the 1970s when complex semiconductor and communication technologies were being developed.

MOSFETThe metal–oxide–semiconductor field-effect transistor (MOSFET) is a type of transistor used for amplifying or switching electronic signals.

MOSFET FABRICATION

p-type Si substrateOxidePolyPatterningn-type dopingMetal

VHDLVHDL (VHSIC(Very High Speed Integrated Circuit) Hardware Description Language) is a hardware description language used in electronic design automation to describe digital and mixed-signal systems such as field-programmable gate arrays and integrated circuits. VHDL can also be used as a general purpose parallel programming language.

VHDL Constructs Entity Declaration

Describes external view of the design (e.g. I/O)

Architecture Body (AB)Describes internal view of the

design Configuration Declaration Package Declaration

Library DeclarationPackage Body