NEMS & MEMS

By:U. Kishore Chandra1155109M.TechS.V.University.

http://ssc.nic.in/

WHY?

Richard Feynman in his famous talk in 1959, "There's Plenty of Room at the Bottom,”.

To avoid mechanical Wear by substituting the electronics.

Fundamental research. Include nonlinear dynamics, origin of sound,

damping and observing quantum effects on mechanical structures.

MEMS:- Micro Electro Mechanical Systems..

NEMS:- Nano Electro Mechanical

Systems.

Electro mechanical systems.

These are devices that convert electrical energy into mechanical and vice versa. Eg. Solenoids, bushless DC motors, Relays etc.

These are sometimes referred to as mechatronics.

These systems can be as simple as push button motor starting circuit or as complex as complete industrial process.

Devices for control of mechanical system using circuits containing a few million transistors.

MiniaturizationAdvantagesIt is a trend to manufacture ever smaller

mechanical, optical and electronic products and devices.

Cost Reduction with improved efficiencies.Improved product and building materials.Ease of transportationHigh precision surgical equipment.Job opportunities in new fields.

HistoryFirst MEMS device a micro mechanical

pressure sensor developed in 1970’s by IBM Later in 1979 HP developed inkjet cartridge

using micro mechanical nozzles. The first VLSI NEMS device was demonstrated

by researcher from IBM in 2000.Its premise was an array of AFM(Automatic

Force Microscopy) tips which can heat or sense a deformable substrate in order to function as memory device.

MEMSTechnology to form small structure with

dimensions in the micrometer scale.It conveys the advantages of miniaturization

multiple components, and microelectronics to the design and construction of integrated electromechanical system.

There are already MEMS around you. In a car, maybe in a television, and in your mobile phone! 

Eg. Cantilever sensorMEMS cantilevers with chemical arrays

attached haveing a natural frequency of vibration which changes as more mass is attached. The change in frequency is sensed MEMS actuator and this can be converted into electrical signal for further analysis.

NEMSIntegrating electrical and mechanical

devices functionality in to the nano-scale.

They typically integrate transistors like nano-electronics with mechanical actuators.

Typical devices having low mass, high mechanical frequencies, use full for surface based sensing mechanisms.

NEMS promise to revolutionize measurements of extremely small displacements extremely weak forces, particularly at the molecular level.

NANO materials: they started with carbon and their behavior depends on morphology.

Benefits of NEMSBenefits include greater efficiency and

reduced size, decreased power consumption and lower cost of production in electromechanical systems.

Small mass and size of NANO machines gives them a number of unique attributes that offer immense potential for new applications and fundamental measurements.

It has high ratings of fundamental power.

Fabrication:

FabricationBasic technologies are:-Deposition:- ability to deposit thin films of

material on substrate.If it is due to chemical depositioni. Chemical vapor depositionii. Electro depositioniii. Thermal oxidation.If it is due to physical reactioniv. Physical vapor depositionv. Casting

lithography:- to apply a patterned mask on top of the films by photolithographic imaging. Image made of polymer coating applied to a flexible aluminum plate. The image can be printed directly from the plate or it can be offset, by transferring the image into a flexible sheet.

Etching:- immersion of a substrate into a solution of reactive chemical that will etch exposed regions of the substrate at measurable rates. In dry itching material is sputtered or dissolved using reactive ions or vapor phase etchant.

Lithography Itching

Application of MEMSMicro engines:- highly compact energy source.Inertial sensors:- Accelerometer, gyroscopic

sensor. Etc.Pressure Sensor:- to measure blood pressure of

fluid pressure.Optical MEMS:- sensing or manipulating optical

signals on a very small size scale using integrated mechanical, optical, and electrical systems .

Fluidc MEMS:-  technology that enables precise, automated manipulation of tiny volumes of fluid mainly used in therapeutics(eg.drug delivery)

Applications of NEMSAccelerometer:-measures the tilting of and orientation

of mobile phones.Nano nozzles:- direct the ink in inkjet printers.Miniature robots:- NANO robots, self assembly robots.Thermal actuators:- these are able to deliver large

force with large displacement to the overall device for small amount of thermal expansion in one part.

Medicine:- it is the largest market for NEMS(eg. pressure sensors to measure blood pressure.)

Bio technology:-lithographic methods to assemble inorganic and metallic materials to layered devices.

Negative impacts:

Material toxicityDifficult in handling.Non- biodegradable materials.Unanticipated consequences.Job losses due to increased manufacturing

efficiencies.

Conclusion:Electrical and mechanical systems working

together perform better.MEMS and NEMS are have very good scope in

present scenario.NANO technology helps in maintaining the

most sophisticated mechanism the we ever know.

Future of these technology may be PEMS,FEMS,AEMS.etc.

References:https://www.mems-exchange.org/MEMS/fabric

ation.htmlhttps://en.wikipedia.org/wiki/Micro-Opto-Electr

o-Mechanical_Systemshttps://en.wikipedia.org/wiki/Nanoelectromech

anical_systemshttps://en.wikipedia.org/wiki/Microelectromech

anical_systemshttp://www.cense.iisc.ernet.in/research/mems

_nems.htm

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