What is “Nano”?

Nano in Greek means ‘dwarf’…..but in actual Nano is even smaller

than dwarf i.e atomic level of anything.
What is “Nanotechnology”?
The ideas and concepts behind nanoscience and nanotechnology started with
a talk entitled “There’s Plenty of Room at the Bottom” by physicist Richard
Feynman at an American Physical Society meeting at the California Institute of
Technology (CalTech) on December 29, 1959, long before the term
nanotechnology was used .
In his talk, Feynman described a process in which scientists would be able to
manipulate and control individual atoms and molecules.
Physicist Richard Feynman, the father of nanotechnology.
This was long before we could see individual atoms that modern
nanotechnology began .

NATURE
One of the largest butterflies in the world, the blue morpho butterfly
outshines others with its vivid blue color. Contrary to popular belief, it is not
pigments that give the wings their bright color. In fact, the wings consist of
thousands of transparent nanostructures.
 butterfly wings appear bright blue due to the constructive interference of
light waves. Their wings consist of many air-sandwiched layers of nano-
scale structures, kind of like fish scales.3 When the light hits these equally
spaced layers, the numerous reflections create constructive interference
patterns resulting in our eye perceiving very intense colors. The tiny
structures also contribute to the selection of colors by only reflecting certain
wavelengths.

Nanoelectronics
Nanoelectronics refers to the use of nanotechnology in electronic components.

Nanoelectronic devices have critical dimensions with a size range between 1 nm and 100 nm.

The term covers a diverse set of devices and materials, with the common characteristic that they
are so small that inter-atomic interactions and quantum mechanical properties need to be studied
extensively.

Quantum effects such as tunneling and atomistic disorder dominate the characteristics of these
nanoscale devices.
Recent silicon MOSFET (metal-oxide-semiconductor field-effect transistor, or MOS transistor)
technology generations are already within this regime, including 22 nanometer CMOS
(complementary MOS) nodes and succeeding 14 nm, 10 nm and 7 nm( 20 billion transistor-based
circuits are integrated into a single chip) FinFET (fin field-effect transistor) generations.

Samsung 2019 risk production of 5nm transistors.

NEED
Moore's law is the observation that the number of transistors in a
dense integrated circuit doubles about every two years. The
observation is named after Gordon Moore, the co-founder of
Fairchild Semiconductor and was the CEO and co-founder of Intel,
whose 1965 paper described a doubling every year in the number
of components per integrated circuit.
The 10 nm and 7 nm semiconductor nodes at Samsung is claimed to
keep pace with Moore's law.
Nano electronics aims at improving the capabilities of electronic
devices and displays while shrinking them and reducing their weight
and power consumption.

WHY NOT MICROELECTRONICS?

The two exceptional disadvantages of micro electronics are:

Physical size
Increasing cost of fabrication of integrated circuits.
NANOELECTRONIC systems can manage and store larger and larger
amounts of information

What does Single-Electron Transistor (SET)

mean?
A single-electron transistor (SET) is a sensitive electronic device based on the Coulomb blockade
effect. In this device the electrons flow through a tunnel junction between source/drain to a
quantum dot (conductive island). Moreover, the electrical potential of the island can be tuned by a
third electrode, known as the gate, which is capacitively coupled to the island. The conductive island
is sandwiched between two tunnel junctions, [1] which are modeled by a capacitor ( and ) and a
resistor ( and ) in parallel

A single-electron transistor (SET) is a switching device that consists of two

tunnel junctions sharing a common electrode and makes use of this
controlled electron tunneling for amplification of current. The technology
used in single-electron transistors is based on the theory of quantum
tunneling. Considered an important component of nanotechnology, single-
electron transistors provide high operating speed and low power
consumption.
There are two categories of single-electron transistors: metallic and
semiconducting.

Single-electron transistors have many applications. They can be used as

ultrasensitive microwave detectors and can also be used to detect
infrared signals at room temperature. They are also efficient charge
sensors capable of reading spin or charge qubits. Their high sensitivity
feature allows them to be used as electrometers in experiments requiring
high levels of specificity.

DISADVANTAGES:
Single-electron transistors are not suitable, however, for complex circuits
owing to the fluctuations present in them.
Other limitations include randomness of the background charge and
difficulty in maintaining the room temperature

graphene transistor
A graphene transistor is a nanoscale device based on graphene, a component of
graphite with electronic properties far superior to those of silicon. The device is a single-
electron transistor, which means that a single electron passes through it at any one time.

A research team led by Professor Andre Geim of the Manchester Centre for
Mesoscience and Nanotechnology built a graphene transistor and described it in the
March 2007 issue of Nature magazine.

Features of the graphene transistor include:

 the ability to operate at room temperature.

 a size one atom by 10 atoms wide.

 extreme sensitivity.

 the ability to operate with the application of very low voltages.

These qualities mean that graphene-based processors could be a fast, low-power successor
to silicon-based processors and enable advances in microchip technology beyond the
capabilities of those using silicon as their semiconductor material.

Electrons can move through graphene at speeds ten to one thousand times greater
than silicon.

Furthermore, unlike silicon, graphene's properties actually improve as the devices

become smaller. 
That capacity, coupled with the ability to operate at room temperature, could allow
more miniaturization which would, in turn, allow more components to be placed on
an integrated circuit (IC).

Scientists have predicted that graphene transistors could scale to transistor channels
as small as two nanometers (nm) with terahertz speeds i.e it could someday
lead to computers that are a thousand times faster and use
a hundredth of the power.

CARBON NANOTUBES:
They were discovered in carbon arc chambers similar to those used to
produce fullerenes.
Single-wall carbon nanotubes are one of the allotropes of carbon, intermediate
between fullerene cages and flat graphene.
Carbon nanotubes can also refer to tubes with an undetermined carbon-wall
structure and diameters less than 100 nanometers.

Properties:
Carbon nanotubes can exhibit remarkable electrical conductivity.
They also have exceptional tensile strength  and thermal conductivity because
of their nanostructure and strength of the bonds between carbon atoms.
In addition, they can be chemically modified.
Carbon nanotubes have useful absorption, photoluminescence (fluorescence)
properties.

USE:
Building transistors from carbon nanotubes enables minimum transistor
dimensions of a few nanometers and the development of techniques to
manufacture integrated circuits built with nanotube transistors.
Researchers at Stanford University have demonstrated a method to make
functioning integrated circuits using carbon nanotubes.
Carbon nanotubes are used to direct electrons to illuminate pixels, resulting in
a lightweight, millimeter thick "nanoemissive" display panel.
Printable electronic devices using nanotube "ink" in inkjet printers
Transparent, flexible electronic devices using arrays of nanotubes.

NANOSENSORS

Nanotechnology deals with physical or chemical properties of matter at the

nanoscale, which can be different from their bulk properties. Nanosensors can
take advantage of these phenomena.
Nanoparticles, primarily noble metal ones, have outstanding size-dependent
optical properties that have been used to build optical nanosensors.
optical nanosensors based on fluorescence measurements have been built
with semiconductor quantum dots and other optical sensors have been
developed with nanoscale probes.
Most sensors based on carbon nanotubes (CNTs) are field effect transistors
(FET) because, although CNTs are robust and inert structures, their electrical
properties are extremely sensitive to the effects of charge transfer and
chemical doping by various molecules.
A graphene nanosensor enables real-time monitoring of insulin at
physiologically relevant concentrations

Nanosensors also have various applications in the environmental

field. The ability to sense for chemicals and biological agents that
are present in the air and water is a concern to environmental
agencies. Nanosensors will innovate the ways air and water quality
is measured due to their size, quickness, and accuracy of
measurements. An example of this is detecting mercury in any
medium (such as air and water) through the use of dandelion-like
Au/polyaniline (PANI) nanoparticles in conjunction with surface-
enhanced Raman spectroscopy (SERS) nanosensors (Wang et al.,
2011).

The ability for nanosensors to measure air quality, particularly for

pollutants, is a new approach to air sampling. Nanosensors have
already been used to measure solar irradiance, aerosol cloud
interactions, climate forcing, and other biogeochemical cycles of
East Asia and the Pacific region. Such instrumentation has been
useful in tracking air pollution in Beijing during the summer Olympic
Games (Dybas, 2008). Nanosensors have also been used by an
Israeli start-up company that will monitor and analyze emissions
from vehicle engines in order to meet the ever increasing strict
standards of American and European Environmental agencies
(Brinn, 2006).
Nanosensors can also be used in monitoring water distribution and
water quality.

Nanotechnology in Displays
OLEDs – organic light-emitting diodes – are full of promise for a range of
practical applications. OLED technology is based on the phenomenon that
certain organic materials emit light when fed by an electric current and it
is already used in small electronic device displays in mobile phones, MP3
players, digital cameras, and also some TV screens.
Areas where nanomaterials and nanofabrication techniques are used in
OLED manufacturing are transparent electrodes (where carbon
nanotubes thin-films are gaining popularity) and nanoparticles-based
coatings for packing the OLEDs to protect them from environmental
damages (e.g. water).
And recently, researchers have even developed brand new concept
of OLEDs with a few nanometer of graphene as transparent
conductor. This paved the way for inexpensive mass production of
OLEDs on large-area low-cost flexible plastic substrate, which could
be rolled up like wallpaper and virtually applied to anywhere you
want.

Nanotechnology in Storage:
We have been using nanotech in this for quite some time for eg.
Flash-based memory chips that are used in computers and cameras today
consist of semiconductor materials that are covered by an insulating
oxide layer, which is only a few nanometres thick. Saving and deleting
data on a Flash storage media is only possible by using a phenomenon of
quantum mechanics and this nanotechnology.
Recently, research has been announced that it is possible to store
data directly in the smallest possible component – an atom! This new
phenomenon was discovered by Dr. Sander Otte a physicist from the
Delft University of Technology, who used chlorine atoms.

Dr. Otte developed a method where the chlorine atoms arrange

themselves on a flat copper surface to form, a two-dimensional
array. According to an article , “By providing fewer chlorine atoms
that would be necessary for the complete coverage, gaps or holes
are created in the array, so-called vacancies. From a gap and a
chlorine atom, a bit may be put together – the smallest information
or memory unit of computers. By moving single chlorine atoms in
and out of vacancies of the array it can be switched between two
states corresponding to the binary code of ones and zeroes which is
the basis on which computers work.”

By using a computer-controlled scanning tunneling microscope his

team was able to pull the atoms from gap to gap until the needed bit
arrays were formed and could be read out.
This technology could mean that this data storage facility that is no
bigger than the surface of a stamp, could store every book that has
ever been created.

TYPES OF ROBOTICS:
Self-reconfiguring modular robot
Modular self-reconfiguring robotic systems are autonomous
kinematic machines with variable morphology ie we can form
them into various shapes according to our use.

Swarm robotics
Swarm robotics is a new approach to the coordination of multi robot
systems which consist of large numbers of mostly simple physical robots.
These consists of multiple robots working in unison.

StructureOfNanorobotics
It consists of :
Molecular sorting rotor
Propellers
Fins
Sensors
For eg. It can be a microscopic machine roaming through the bloodstream,
injecting or taking samples for identification and determining the
concentrations of different compounds.
Benefits Of Nanorobotics
Speed up of medical treatment
Faster and more precise diagnosis
Minimum side effects

Transparent Electronics
transparent solar cells would enable Display panel to obtain solar power
while user was looking at screen
Requirements for TCF(transparent conducting films) of transparent
electronics
• Non-toxic elements and cheap material • Good conductivity with good
transmittance • Bandgap energy with High mobility • Good reliability •
Cheap processing and mass production
WHY GRAPHENE??
Graphene: Carbon. Can be found everywhere, very cheap, non-Toxic.
Good conductivity with good transmittance
In an insulator or semiconductor, an electron bound to an atom can break
free only if it gets enough energy from heat or passing photon to jump
the ‘band gap’. But in graphene the gap is infinitesimal. This is the main
reason why graphene’s electron can move easily and very fast.
Strength & Flexibility good as compared to indium tin oxide(ITO)