VITech: 'Graphene' - The Future of Engineering (Part 2)

Part - 2

1) Monolayer sheets

In 2013, different scientist came together and they presented a production unit. This unit helps to produce graphene monolayer sheets. This production unit uses liquid metal matrix on which graphene gets grow. This process creates polycrystalline graphene know as high strength metallurgical graphene (HSMG). Grolltex is one of the famous manufacturing industries of the monolayer sheets. They can produce monolayers up to 8 inches diameter.

2) Bilayer graphene

As the name bilayer itself indicates that it consists two layers of graphene. This form of graphene is used in optoelectronic and nanoelectronics applications. Bilayers shows tuneable band gap and excitonic condensation makes form very special in above mention applications. There are different types of stacking of the two layers. AA-stacked bilayer, AB-stacked by layer and twisted bilayer are the methods to stack. First bilayer was formed in the year 2004 by Mr. Geim. CVD is the effective technique to produce bilayers in the large scale.

3) Graphene superlattices

Superlattices formed by stacking graphene layers which provide fascinating structural element and highly functional atomic scale. This form of graphene is widly used in nanoelectronics and photonic devices. Phonon (quantum of vibration of mechanical) thermal transport can be visualized with help of superlattices. This is the ideal model which makes possible to understand the wave like and particle like study of phono.

4) Nanoribbons

Graphene nanoribbons are also known as nano graphite ribbons having width of just 100nm. Mitsutaka Fujita first introduced the nanoribbons to the world. It is very difficult to produce nanoribbons precisely. It has the value of Youngs modulus of over 1 TPa. Its edge structure is the zigzag manner which decides the electronic states of ribbon.

5) Quantum dots

Graphene quantum dots (GQds) are nano particles of the graphene. They are less than 100nm in the size having properties like low toxicity, chemical stability as well as quantum confinement effect. They are used in biological, energy and environment applications.

1) 6) Graphene oxide

Graphene oxide formed by using paper making techniques which oxidized the graphite element forms the single sheets with strong bonds. It has tensile strength of 32 GPa. It enhanced the photo conducting properties of the polymers. As graphene is the vacuum-tight material but after converting into the graphene oxide water and vapour easily gets passed through it.

7) Graphene fibre

Scalable and controllable CVD method is effective way to produce graphene films precisely and this form rose in 2011. CVD delivered tuneable morphology as well as the pore structure by controlling evaporation of solvents with precise surface tension. Graphene fibres first used in supercapacitors in 2013 in the solid state. Fibres provide thermal and electrical conductivity in the greater way, with the highest mechanical strength. It is widely used in the textile industry, light weight vehicles, micro electronic devices. It has 80GPa tensile strength.

1) 8) 3D graphene

Graphene atoms are hexagonally arranged in such way that they form the three-dimensional honeycomb structure formed 3D graphene. CVD is mostly used methods to produce 3D structure. 3D graphene came into the picture in the year 2013 by stony Brook. He fabricated 3D porous and free-standingarchitecture of graphene. He used radical initiated crosslinking method. Mr. Khurram introduced new technique of the production that is then-state-of-the-art for the 3D graphene structure in the year 2016. These 3D graphene are used in the energy storage, filtration, thermal management and biomedical devises.

9) Pillared graphene

Pillared graphene is one of the hybrid carbon structure. It consists oriented array of nanocarbon connected at end of the graphene sheets. This concept arose in 2008 in the mind of George Froudakis and he described theoretically in the university of Crete in Greece. It is not implemented yet but it has the great future in the electronic industry. Its poses useful electronic properties. It can be also useful for hydrogen storage tank material.

10) Aerogel

One of the interested forms of graphene is Aerogel. It weighs just 0.16 milligrams per cm³. Aerogel is obtained from the solution of graphene and carbon nanotubes. This solution first freezes dried and then dehydrate the solution which produced the Graphene aerogel. This form has the superior elasticity. It can recover 90% of the compression. Its absorption capacity is also great which can absorb up to 900 times of its own weight. The rate of absorption is 6808 grams per seconds. It is the lightest material form ever.

1) 11) Nano coil

Nano coils are discovered in the year of 2015. Production of nano coils is possible because of the defect in the material having the hexagonal grids which cause it to spiral along its edge. When we apply voltage to this nano coils, flowing current around this coil produced the magnetic field. Solenoid made up of these coils acts as the quantum conductor. Its current distribution varies in between of core and the exterior walls which produced nonlinear inductance.

12) Crumpled graphene

Crumped graphene has wrinkles on the material in the nanoscale. This technique of crumpling on the graphene is introduced by the Brown university in the year of 2016. For getting this form of graphene the shrink films are used on which graphene oxide layer deposit. The graphene oxide gets converted into the superhydrophobic crumpled graphene which is used in the battery electrodes.

Application of Graphene:

A. Applications in Energy industry

1) Solar cell

From many of the year’s scientist work to develop lighter, flexible and transparent solar cells. But the Major problem was of finding of such material which has all the properties and able to carry current. Indium Tin oxide has been used because it poses all the properties except flexibility. But discovery of graphene changes the traditional way and in 2017 researchers managed to apply graphene on solar cells. So, the flexible and transparent solar cells were produced which can be mount on cars, cloths, cell phones, etc.

1) Batteries

Graphene enhanced the working of traditional lithium batteries. It provides longer lifespan, higher capacity as well faster charging time. Graphene batteries are light in weight and flexible which makes them to use in the wearable electronics.

A. Applications in medicine

1) Graphene in Dialysis

As graphene plays various roles in all industry. With addition to that is also able to filter the blood. Researchers showed that it can be used to filter blood from chemical and drugs as well. Superiority of graphene is 20 times greater than the traditional methods.

1) 2) Photothermal therapy

Photothermal therapy is used to eliminate abnormal cells by irradiating special agent which destroy those cells with the help of heat. Graphene oxide increase the working and the effectiveness of this therapy. With the help of graphene oxide, we can implement both chemo therapy and photothermal therapy combinedly. So that it will give better result of destroying tumours. Doing this therapy, it can not damage the healthy cells.

A. Applications in electronics

1) Transistors

Graphene replaces the silicon in the production of transistors. This increases speed of computers up to 1000 times. This will lead technology on the next level as it saves the time and increases the functionality. Graphene will make the world faster. Graphene provides high carrier mobility and creates very low noise.

2) Waterproof and Wearable electronics

Major problem of electronic devices is that they get damaged when they come in contact of the water. Graphene is the best solution on such problems. Graphene is strong, transparent and able to conduct electricity. That’s why engineers of Lowa state university print the circuits of the device with the help of graphene flake. With waterproof electronics scientist are also working on wearable electronics. Graphene made flexible batteries printed on a fabric. This will create electronic environment friendly and smart e-textile which can store energy. This will send all digital gadgets in to the history.

1) 3) Flexible and touchscreen

Indium tin oxide (IOT) is used commercially for the screen of smartphones, computer, etc. Researchers of Rice university developed graphene thin films for smartphone which beats the IOT. Graphene provides lower resistance and the higher transparency which increase the performance of digital devices. Chine has produced flexible smart phones with help of graphene. This graphene screens are are strong light in weight and transparent. It gives all the requirement of smartphone working with great satisfaction. Smart phones made up of graphene weighs 200 grams only. Hence graphene will bring the technology on the next level in the future.

A. Applications in sports

1) 1) Shoes

Graphene is not purely used in shoes but it is used in composite form. It is proven that sole made of graphene have a life of hundreds of years. University of Manchester and sport Invo-8 brand produced shoes made up of graphene. These shoes increase the strength and provide flexibility properties increased by 50%. These shoes are more durable than traditional. Graphene shoes are able to absorb shock and the impact which could damage the bones and joints. It protects the body part most efficiently.

1) 2) Rackets

Graphene is upgrades energy distribution equally. Weight of racket gets reduced whereas the service speed and the stability gets increased. Tennis equipment company named as HEAD developed the graphene racket series whose name is “GRAPHENE 360 SPEED PRO”. Novak Djokovic used this racket for the first times. Graphene will give better performance in the sport field also.