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1. Nano electromechanical systems Presented by SYEDA
NASIHA
2. INTRODUCTION Nano-Electro-Mechanical systems (NEMS)
integrate electrical and mechanical functionality on the nanoscale.
The Nano mechanical components are fabricated using compatible
micromachining process.
3. Nano electro mechanical devices promise to revolutionize
measurements of extremely small displacement and extremely weak
forces, particularly at the molecular level. NEMS devices can be so
small that hundreds of them can be fit in the same space as one
single micro device that performs same function.
4. Nano-electronic integrated circuits allow nano systems to
sense and control the environment. In Nems devices the sensors
gather the information from surrounding environment through
measuring mechanical, chemical, biological, chemical and optical
phenomenon. The electronics then process the information derived
form the sensors. Through some decision making capability direct
the actuators to respond by moving, regulating and filtering.
5. Electro mechanical systems: The device illustrates the two
principal components common to most electromechanical systems
irrespective of scale: a mechanical element:includes moveable
structures such as beams,gears. transducers.:small motors and
integrated circuits. the output of an electromechanical device is
the movement of the mechanical element.
6. BENEFITS OF NANO MACHINES The small mass and size of Nano
machines gives them a number of unique attributes that offer
immense potential for new applications and fundamental
measurements. A second important attribute Nano machines is that
they dissipate less energy.
7. Nano machines are extremely small . Nano machines are ultra
low power devices. Fundamental power scale is defined by the
thermal energy divided by the response time
8. fabrication of nems device There are three Basic building
blocks in NEMS technology. Deposition processes. Lithography.
Etching processes.
9. Deposition Process : Chemical methods used in NEMS
deposition process. o Chemical vapour deposition. o Epitaxy.
12. Lithography : Lithography in the NEMS context is typically
the transfer of a pattern to a photosensitive material by selective
exposure to a radiation source such as light. A photosensitive
material is a material that experiences a change in its physical
properties when exposed to a radiation source.
13. Pattern Transfer : Fig 3: Transfer of a pattern to a
photosensitive material
14. Figure 4:a) Pattern definition in positive resist, b)
Pattern definition in negative resist.
15. Alignment : Inorder to make useful devices the patterns for
different lithography steps that belongs to a single structure must
be aligned to one another. It is important for each alignment mark
on the wafer to be labeled so it may be identified, and for each
pattern to specify the alignment mark to which it should be
aligned.
16. Exposure : This parameter is required in order to achive
accurate pattern transfer from the Mask to the photo sensitive
layer. Different Photo resist exhibit different sensitivity to
different wavelengths
17. Etching : It is necessary to etch the thin films previously
deposited or the substrate itself. There are 2 class of etching
process. Wet etching. Dry etching.
18. ADVANTAGES o Cost effectiveness. o System integration. o
High Precision. o Small size. o High sensitivity
19. APPLICATIONS OF NEMS Accelerometer : NEMS accelerometers
are quickly replacing conventional accelerometers for crash air-bag
deployment systems in automobiles. Figure 6 : Accelerometer(air
bags)
20. Nano nozzles: Another wide deployment of NEMS is their use
as nano nozzles that direct the ink in inkjet printers. They are
also used to create miniature robots (nano-robots) as well as
nano-tweezers. NEMS have been rigorously tested in harsh
environments for defense and aerospace where they are used as
navigational gyroscopes.
21. NEMS in Wireless : A 3G smart phone will require the
functionality of as many as five radios for TDMA, CDMA, 3G,
Bluetooth and GSM operation. A huge increase in component count is
required to accomplish this demand.
22. Thermal actuator : Thermal actuator is one of the most
important NEMS devices, which is able to deliver a large force with
large displacement.
23. Thermal actuator : Thermal actuator is one of the most
important NEMS devices, which is able to deliver a large force with
large displacement.
24. DRAWBACKS NEMS technology is currently used in low- or
medium- volume applications. Some of the obstacles preventing its
wider adoption are: Limited Options Packaging Fabrication Knowledge
Required
25. FUTURE OUTLOOK NEMS offer unprecedented and intriguing
opportunities for sensing and fundamental measurements. In the
future, complex molecular-scale mechanical devices will be
mass-produced by placing millions of atoms with exquisite precision
or by some form of controlled self-assembly. This will be true
nanotechnology.
26. The focus on the exploration of NEM-physics and the
development of NEM-devices can be used as extremely sensitive
sensors for force and mass detection down to the single molecule
level, as high-frequency resonators up to the GHz range Typically,
high-frequency electrical resonators have Q values less than
several hundred.
27. CONCLUSION Nano-systems have the enabling capability and
potential similar to those of nano-processors . Since NEMS is a
nascent and synergistic technology, many new applications will
emerge, expanding the markets beyond that which is currently
identified or known.
28. NEMS is forecasted to have growth similar to its parent IC
technology. For a great many applications, NEMS is sure to be the
technology of the future.
29. REFERENCES [1] James E.Hughes Jr;Massimiliano Di
Ventra;Stephane Evoy(2004).Introduction to nanoscale science and
technology. [2] Despont
M;Brugger,J;DRECHSLER,U;Durig,U;Haberle,W,Lutwyche
,M;Rothuizen,H;Stutz,R,et al(2000).VLSI-NEMS chip for parallel AFM
data storage. [3] Ke,Changhong;Espinosa,Horacio D(2005).Numerical
analysis of nanotube_based Nems devices_part 1. [4] Global Market
of NEMS projections