GRAPHENE - SCI & TECH
News:
What is magnetoresistance? It’s one more thing graphene does differently.
What's in the news?
● Researchers
in the UK, led by Nobel laureate Andre Geim, have discovered another property
of graphene – a single-atom-thick layer of carbon atoms bonded in a honeycomb
pattern – that further distinguishes this ‘wonder’ material.
Key takeaways:
● Dr.
Geim & co. found that graphene displays an anomalous giant
magnetoresistance (GMR) at room temperature.
Giant Magnetoresistance (GMR):
● GMR
is the result of the electrical
resistance of a conductor being affected by magnetic fields in adjacent
materials.
● GMR-based
devices are particularly used to sense
magnetic fields.
● It
is used in hard disk
drives and magnetoresistive RAM in computers, biosensors, automotive sensors,
microelectromechanical systems, and medical imagers.
How is GMR unique in
Graphene?
● The
magnetoresistance observed in the graphene-based device was “almost 100-times higher than that observed in
other known semimetals in this magnetic field range.
● Conventional
GMR devices are cooled to low temperatures to suppress the kinetic energy of their
constituent particles, keeping them from deflecting the electrons moving past
them. In graphene, the researchers found this suppression unnecessary.
Go back to basics:
Graphene:
● Graphene
is a single layer (monolayer) of carbon
atoms arranged in honeycomb-like patterns.
● Often
referred to as a wonder material for its extraordinary
electrical and electronics properties having vast potential in the energy
and medical world.
● Graphene
could replace Indium and thereby
bring down the cost of OLED (organic light-emitting diode) screens in
smartphones, studies have shown.
Key Properties:
● It
is the building-block of Graphite, but graphene is a remarkable substance on
its own with a multitude of astonishing properties.
● It
is the thinnest, most electrically and
thermally conductive material in the world, while also being flexible, transparent and incredibly strong.
● It
is about 200 times stronger than steel.
● It
is a better conductor of electricity
& heat compared to copper.
● It
is nearly transparent and is impermeable
to gases.
● All
these properties are exciting researchers and businesses around the world – as
graphene has the potential to revolutionize entire industries – in the fields of electricity, conductivity, energy
generation, batteries, sensors and more.
Uses:
● It
can be used in applications ranging from miniaturized
electronics to biomedical devices like computers, batteries, and other
devices, anti-corrosion coatings and paints, efficient and precise sensors,
faster and efficient electronics, flexible displays, efficient solar panels,
faster DNA sequencing, drug delivery, and more.