U. Kishore Chandra
Richard Feynman in his famous talk in 1959, "There's Plenty
of Room at the Bottom,”.
To avoid mechanical Wear by substituting the electronics.
Include nonlinear dynamics, origin of sound, damping and
observing quantum effects on mechanical structures.
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.
It 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 transportation
High precision surgical equipment.
Job opportunities in new fields.
First MEMS device a micro mechanical pressure sensor
developed in 1970’s by IBM
Later in 1979 HP developed inkjet cartridge using micro
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.
Technology to form small structure with dimensions in the
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 sensor
MEMS 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
Integrating electrical and mechanical devices functionality in
to the nano-scale.
They typically integrate transistors like nano-electronics with
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 NEMS
Benefits 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.
Basic technologies are:-
Deposition:- ability to deposit thin films of material on
If it is due to chemical deposition
i. Chemical vapor deposition
ii. Electro deposition
iii. Thermal oxidation.
If it is due to physical reaction
i. Physical vapor deposition
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.
Application of MEMS
Micro engines:- highly compact energy source.
Inertial sensors:- Accelerometer, gyroscopic sensor. Etc.
Pressure Sensor:- to measure blood pressure of fluid
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
Applications of NEMS
Accelerometer:-measures the tilting of and orientation of mobile
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.
Difficult in handling.
Non- biodegradable materials.
Job losses due to increased manufacturing efficiencies.
Electrical and mechanical systems working together perform
MEMS and NEMS are have very good scope in present
NANO technology helps in maintaining the most
sophisticated mechanism the we ever know.
Future of these technology may be PEMS,FEMS,AEMS.etc.