Graphene

Graphene

1. Chicken wire made of carbon

   • The scientists discover that:
     • It conducted electricity better than any other common substance, it was the thinnest material known (only one atom thick), and it was stronger than steel!
   • Carbon occurs in many crystalline forms, called allotropes.
     • Allotropes are different forms of the same element with different bonding arrangements between the atoms.
   • Graphite and dimond
     • Graphite, each atom is bonded to three others in layers of hexagonal (six-sided) shapes that look like chicken wire
     • Diamond, each carbon atom is connected to four other carbons
   • Andre Geim y Konstantin Novoselov
     • Used this property to produce samples of graphene and discover its remarkable properties
     • The initial graphene samples were very small, just a couple of square millimeters each, but big enough to test.
     • It is the thinnest material and 100 times stronger than steel.
     • Electrons do not scatter as much when moving as they do in other materials

2. Flexible solar panels

   • Graphene has generated interest from engineers trying to make solar panels
   • Graphene is almost transparent to light and absorbs only 2% of the light that falls on it and has the ability to conduct electricity.
   • When a photovoltaic cell is sandwiched between two graphene sheets, light crosses the graphene sheets and hits the photovoltaic cell.

3. Foldable cell phones

   • A layer that stores electrical charge is placed on the glass panel of the screen.
     • When a user touches the screen with their finger or a stylus, some of the charge is transferred to the user, so the charge on the layer decreases.
   • Most of today's portable devices have screens coated with a conductive layer made of indium tin oxide.
   • Touch screens made with graphene as a conductive element could be printed on thin plastic
     • Could make cell phones as thin as a sheet of paper
     • Also, due to the incredible strength of graphene, these cell phones would be nearly unbreakable.

4. Bionic devices

   • The term "bionics," a mix of "biology" and "electronic," refers to devices that assist or enhance an organ or tissue,
     • Bionic devices made of graphene could have a long life
   • It can connect with neurons, which also send weak electrical signals from one cell to another.
   • This type of technology could be used to control a mechanical artificial arm or leg.
     • The graphene bionic device could transmit electrical signals to the tiny motors in an artificial limb, causing it to move.
   • One of the hurdles that must be overcome is how to make sheets of graphene large enough and pure enough (containing only carbon) to be useful.
   • A commonly used method, called chemical vapor deposition, involves passing methane gas (CH 4 ) over a sheet of copper.
     • In another method, graphite is dissolved in a solvent and then sprayed on in thin layers using inkjet printers.

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