2. This technology makes use of the material that can
convert waste heat energy from various process
around us into an useful electrical energy. This
waste heat requires a material which can absorb it.
The material used to absorb heat is silicon nano
wire. The Nano wire can convert heat energy into
electrical energy by means of Thermo-Electric
effect. The material has a special property that it
can conduct only electricity and heat waves are
reflected back, and it has a very low thermal
conductivity.
3. “ Electric current can be produced when one end
of the material is kept at higher temperature while
keeping the other end is at lower temperature”
THERMO ELCETRIC EFFECT
To establish the concept of thermo-electric
effect Si Nano Wires were invented.
“ Thermoelectricity makes it possible to
cleanly convert heat directly into electrical
energy in a device with no moving parts," said
lead author Justin Bergfield.
4. Thermo-electric conversion efficiency is a
factor that measures the fluctuation of Thermal
conductivity and Electrical conductivity.
Z is the square of thermo-electric power
divided by the product of electrical resistivity
and thermal conductivity.
T is the temperature in Kelvin
5.
6. According to coke can’s nutrition facts label
the average human consumes approximately
2000 calories per day.
This means that the average person expends
8.37 x 106 joules of energy per day .
Most of the expended energy leaves in the form
of heat
Generally humans can radiate 350,000 joules
of energy per hour, this is roughly equal to the
energy given off by a 100 watt bulb.
7. In automobiles, to improve the fuel economy
by exploiting the new controls approach that
uses the waste heat from engines.
Mostly 65% of heat energy is produced in
internal combustion engines, whether diesel is
wasted .
65% of
heat is
produced
8. Mobile devices have a very different set of
thermal constraints.
Desktop computers are housed in large
enclosures and are cooled by thick metal heat-
sinks with a large and often loud fan.
Nowadays almost all phones heat up. The
iPhone is famous for heating.
Which determines battery supplies more
power ,this leads to battery heating up.
9. Our proposed work first aims at production of
silicon nano wires semiconductors with other
elements like phosphorous or boron through
RIE(RADIOACTIVE ION ETCHING)and
plasma etching.
Then,theFabrication of Silicon nano wafers
are implemented through Welding and
smouldering technique.
Once Silicon nano wires are created they are
made to absorb heat from components and
generates electricity .
11. Can be used in all areas where waste heat is
generated .
12. Can be Used in aeronautics mainly in brakes
where loss of energy is more than 30%.
In Automobiles exhaust engine where 60-75%
of heat are energized as exhaust system gets
heated upto 700 deg Celsius.
Laptops,Mobiles and other accessories where
charger can be used for additional work.
Also in many Biomedical industries as
nanotechnology is growing rapidly.
13. DKC Mac Donald, “Thermo electricity–An
introduction to the principle”,1962,Wiley,New
York
I. Hochbaum, R. Chen, R. D. Delgado, W. Liang,
E. C. Garnett, M. Najarian, A. Majumdar, and P.
Yang, “Enhanced thermoelectric performance of
rough silicon nanowires” ,Nature 451, 163 (2008).
Neil Savage IEEE Spectrum, “Thermoelectric
converters could tap waste heat from power plants
and microchips”.
Foster, L., 2006, “Nanotechnoloy: Science,
Innovation, and Opportunity”, Prentice Hall,
Upper Saddle River, NJ.
14. This paper presented an efficient way of
application of Nanotechnology for the production
of electricity from the waste form of heat energy.
It also mitigates the cheaper and easier method of
production of silicon nano wires and its use in
various fields. Research still underway in
Silicon-Germanium Nano wires. which is still
more better in some properties as compared to
silicon nano wires.
