2. WHAT IS NANOTECHNOLOGY ?
Nanotechnology broadly includes all
technologies that handle nano-scale
materials, and in a narrow sense,
technologies that handle unique
phenomena that arise in the 10-to-100-nm
size range.
Carbon
Nanofibre
(a single
human
hairis 1000
times
thicker
than any of
the
nanofibres
in the
image).
4. NEW PROPERTIES
At the nanoscale, matter begins to
demonstrate entirely new and unique
properties. It can become stronger,
conduct heat better, and show
extraordinary electrical properties.
8. WHY NANOTECHNOLOGY MATTERS ?
• The advances in nanotechnology have brought new
tools to the field of electronics and sensors.
• For instance, at the nanoscale, the resistance
dependence of a material on an external magnetic
field is significantly amplified, which has led to the
fabrication of hard disks with a data storage density
in the gigabyte and terabyte ranges.
10. CARBON BASED SENSORS AND ELECTRONICS
Carbon nanomaterials such as one-
dimensional (1D) carbon nanotubes and
two-dimensional (2D) graphene have:-
• Superior electrical properties which allow
for fabrication of faster and more power-
efficient electronics.
• High surface to volume ratio.
• Excellent mechanical properties rendering
them as a robust and highly sensitive
building block for nanosensors.
11. •Graphene transistor
• Graphene is a single sheet of carbon atoms packed in a
honeycomb crystal lattice, isolated from graphite.
• Allows electrons to move at an extraordinarily high speed.
• With its intrinsic nature of being one-atom-thick, can be
exploited to fabricate field-effect transistors that are faster
and smaller.
12. • Carbon nanotube electronics
When a layer of graphene is
rolled into a tube, a single-
walled carbon nanotube
(SWNT) is formed. The
cylindrical structure and
high electron mobility makes
them a more readily
available option for forming
the channel in field-effect
transistors. These have
advanced to logic gates and
radio-frequency
components.
13. • Carbon-based nanosensors
• Graphene and carbon nanotubes have excellent thermal
conductivity, high mechanical robustness, and very large
surface to volume ratio making them superior materials
for fabrication of electromechanical and
electrochemical sensors with higher sensitivities, lower
limits of detection, and faster response time.
Any additional gold atom that adsorbs
on the surface of a vibrating carbon
nanotube would change its resonance
frequency which is further detected.
14. MOLECULAR ELECTRONICS
• Recent advances in nanofabrication
techniques have provided the opportunity to
use single molecules, or a tiny assembly of
them, as the main building blocks of an
electronic circuit.
• Enabling the realisation of novel
functionalities beyond the scope of traditional
solid state devices.
15. • Single Molecule Memory Device
A modern memory device, stores each bit of data by charging
up a tiny capacitor. As memory device dimensions approach
the nanometer range, the capacitor can be replaced by a
single organic molecule such as Ferrocene, whose oxidation
state can be altered by moving an electron into or out of
the molecule.
16. • Organic transistor odour sensor
In an odour sensor, for instance, the nano-scale
chemical reactions upon exposure of the device
to a certain atmospheric condition modify the
electronic properties of the organic
semiconducting material which is further
reflected by a change in the current flowing
through the transistor.
17. QUANTUM COMPUTING
Quantum algorithms are implemented in a
device that makes direct use of quantum
mechanical phenomena such as
entanglement and superposition.
Nanotechnology uses the fact that the
physical laws that govern the behaviour of
a system at the atomic scale are
inherently quantum mechanical in nature.
18. SINGLE ELECTRON TRANSISTOR
• A single electron transistor
needs only one electron to
change from the insulating
to the conducting state.
• Deliver very high device
density and power
efficiency with remarkable
operational speed.
• Quantum dots with sub-100
nm dimensions have to be
fabricated.
19. SPINTRONICS
Spintronics employs the spin of electrons to
encode and transfer information. It has the
potential to deliver nanoscale memory and
logic devices which process information
faster, consume less power, and store more
data in less space. The extension of the hard
disk capacities to the gigabyte and the
terabyte ranges was the main achievement
of spintronics by taking advantage of Giant
Magneto-Resistance (GMR) and Tunnel
Magneto-Resistance (TMR) effects which are
effective only at the nano scale.
20. NANO-ELECTRO-MECHANICAL
SYSTEMS (NEMS)
• Nano-electro-mechanical systems have
evolved during the last 10 years by creating
sensors (“eyes”) and actuators (“arms”).
• Recent developments in synthesis of
nanomaterials with excellent electrical and
mechanical properties have extended the
boundaries of NEMS applications to include
more advanced devices such as the non-
volatile nanoelectro-mechanical memory,
where information is transferred and stored
through a series of electrical and mechanical
actions at the nanoscale.
22. Hybrid Si NanoCones/Polymer
Solar Cell• Si nanocones
fabricated by
colloidal lithography
were covered with a
conductive polymer,
which formed a
Schottky junction
between the Si and
polymer.
• The power
conversion
efficiency of the
hybrid Si/polymer
device was more
than 11 %.
24. • Computer processing
Moore’s Law
describes a
trend of
technology. It
states that the
number of
transistors that
can be put on a
single chip will
double every
two years.
26. • Memory and storage
2 GB in 1980s
$80,000
2 GB in 1990s
$200
2 GB in 2010
$5
27. • Displays
Carbon nanotubes on a glass or plastic sheet allow
manufacturers to make clear conductive panels
for displays that are extremely thin.
28. Restoring Sight to the Blind
• Blindness due to loss of photoreceptors.
• Sight can be restored by patterned electrical
stimulation of the surviving inner retinal
neurons.
• Photovoltaic subretinal prosthesis directly
converts pulsed light into pulsed electric current
in each pixel, stimulating nearby neurons.
• Visual information is projected onto retina by
video goggles using pulsed NIR (~900 nm) light.
Photovoltaic arrays including 3 diodes in each
pixels were fabricated in SNF.
30. Cancer Detection
• Motivation – Earlier
cancer detection
• Development of
nanomagnetic
sensor chip
– Use same principles
employed in
magnetic storage
industry
– Use magnetic
nanoparticles to
‘tag’ proteins
indicative of cancer
31. Nanostructures in Nature
• A moth’s eye has very small bumps on its surface. These patterns
are smaller than the wavelength of visible light (350-800nm). The
eye surface has a very low reflectance for the visible light. The
moth can see much better than humans in dim or dark conditions
because these nanostructures absorb light very efficiently.
• On the surface of a butterfly’s wings are multilayer nanoscale
patterns. These structures filter light and reflect mostly one
wavelength, so we see a single bright color. Due to multiple layers
in these structures optical interferences are created (wings of male
Morpho Rhetenor appear blue).
• The edelweiss (Leontopodium nivale) is an alpine flower found at
high altitudes, where UV radiation is strong. The flowers are
covered with thin hollow filaments that have nanoscale structures
(100-200nm) on their periphery. They will absorb ultraviolet light,
but reflect all visible light. This explains the white color of the
flower. It also protects the flower’s cells from possible damage due
to this high-energy radiation.
33. • Providing realistic, cost-effective methods
for harnessing renewable energy sources
and keeping the environment clean.
• Doctors detecting disease at its earliest
stages and treating illnesses such as cancer,
diabetes, heart disease with more effective
and safer medicines.
• New technologies for protecting both
military forces and civilians from
conventional, chemical and biological
weapons.