Researchers Introduce Graphene Printing Technique that Silk-Screens Flexible Electronics

As technologies advance quickly with promises of an explosion of new products ranging from electronic and microelectronic components to solar panels, there is also an expectation of rapid development in the nanotechnology research field.

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Innovative discoveries are responding to industry needs. They are bringing closer to reality things such as high-efficiency solar cells molded to the surface of a vehicle, ultra-small photonics chips, and low-power, long-lasting wearable devices. 

What they all have in common is the urgent need for chips made from high-efficiently materials with the characteristics of being flexible, thin, and also inexpensive to manufacture.

Making wearables using ultra-flexible electronics which are also low-power is a holy grail in the field of semiconductor manufacturing. The same can be said about the Internet of Things (IoT). 

Massachusets Institute of Technology (MIT) researchers have found a way to grow a single crystalline compound semiconductor on its substrate through two-dimensional materials. When the compound semiconductor thin-film is exfoliated by a flexible substrate it shows the rainbow of colors that come from thin-film interface. 

This means that industries such as solar energy, photonics, wearables, and Internet of Things (IoT) can benefit from the new discovery, making prototypes and ideas closer to the consumer. 

The research group led by Jeehwan Kim, who is associate professor of mechanical engineering and materials science at MIT, published the developments that bring semiconductor innovations closer to achievable in both the Nature Materials and Science journals.

The innovations mean they now can inexpensively mass-produce ultra-thin gallium arsenide and gallium nitride chips. They can also harvest the monolayer materials that are necessary for manufacturing 2D electronics such as tiny photonics devices.

“We [found] the way to go to expensive semiconducting materials so you can keep producing high-quality, high-performance semiconductors with a cheaper price,” says Jeehwan Kim. “The bonus is you can have flexible semiconducting devices, and because they’re really thin, you can stack them up.”

Semiconductors that can be laid down on graphene sheets

According to IEEE Spectrum, last year, professor Kim's group were already working on the use of graphene sheets as nanosize silk-screens through which expensively manufactured exotic-material-based semiconductors can be laid down. 

“We were able to copy-paste through graphene for many types of compound materials in the periodic table,” says Kim. By using the term copy-paste he means to describe the simple and inexpensive procedure that his team has developed.

“That is a big discovery. Based on that understanding, we were able to make single-crystalline, freestanding, very, very thin membrane compound materials.”

According to professor Jeehwan Kim, his research group has already been working with six major companies to scale up the ultra-thin chip manufacturing processes.

Some of these technologies are going to be tested in different scenarios before being made available for commercial applications. The companies with which the researchers are collaborating are based in Korea, Japan, and the United States. 

Ultra-flexible electronics for e-skin 

E-skin is ultra-flexible, ultra-thin electronics that can stick to human skin. The electronics skin can be used in countless medical innovations. Professor Takao Someya, from the University of Tokio in Japan, has been developing flexible, stretchable, and bendable electronics for a decade.

Professor Someya wants to develop electronics that can be applied as human skin. The main challenge he has found in his decade-long study in the manufacture of e-skins is to produce flexible electronics.

Thin-film transistors can be printed on transparent films. With added flexibility, they can be used for medical applications. In the future, there could even be synthetic skins for humans or robots. 

Graphene was discovered in 2004: It was the beginning of a new era in electronics

Graphene, the thinnest material in the world, is highly regarded as one of the most important discoveries of the 21st century. In 2004, Andre Geim and Konstantin Novoselov, researchers at the University of Manchester, England discovered graphene.

By using regular Scotch tape the physicists managed to separate thin flakes of carbon from a piece of graphite. The scientists openly shared the results of their discovery with other labs in the world. They thought that was the right thing to do and never regretted about it. 

After being awarded the Nobel Prize in Physics 2010 for their discovery of graphene, Andre Geim and Konstantin Novoselov donated a piece of graphite, a roll of Scotch tape, and a graphene transistor to the Nobel Museum in Stockholm, Sweden. The original donation is seen here below: 

Professor Konstantin Novoselov on the discovery of graphene

Graphene is a single-atom layer of graphite with properties that break records in strength, electricity, and heat conduction."The original question was: can we make a transistor out of graphite?" That's how graphene was born, after several attempts with no results, one Friday in Manchester graphene was born.