Saturday, August 31, 2013

Foldable and printable electronics possible with graphene

Advances in electronics have expanded the range of applications. One new application of electronics that is becoming more prevalent is insertion into the human body. Current silicon-based electronics are not flexible enough to allow proper integration into the human body in most cases.

Graphene, a fairly new nanomaterial, could solve this problem. It is the best candidate for creating foldable circuits because it is highly conductive, chemically stable, and mechanically flexible. This means that it can exist in thin layers that would bend easily while still being an effective conductor. This is possible because graphene is incredibly strong, about 200 times stronger than steel. The scientists that were able to produce a 1-atom thick sheet of graphene, Andre Geim and Kostya Novoselov from the University of Manchester, were awarded the Nobel Prize for physics in 2010.

Researchers at Northwestern University in Illinois are creating electronics with paper-like properties by using graphene. These could open new doors in the implementation of electronics into the human body and in medical devices. The development of foldable electronics could also spark new development of electronics based on the foldable ones.

The first problem that arises when using graphene is that it is difficult to obtain. The traditional way of obtaining graphite was to break it off of graphite molecules using an oxidization process. This was effective at creating the graphene, but it lost much of its conductivity in the process, making it unusable in electronics.

The researchers at Northwestern University have used a different method to obtain the graphene. They perform exfoliation on the graphite using ethanol and ethyl cellulose. This process is more effective than the oxidization because it creates little waste, and most importantly, creates graphene with its original high conductivity. This new process is not only important in creating circuits, but could find application in any technology where graphene is needed.

Now that the graphene has been obtained, the next step is to apply it to the paper, or whatever material the circuit is being produced on. The researchers at Northwestern University found a way to incorporate the ~1 nm (one 10,000th the size of a red blood cell) sized flakes of graphene into inkjet printer ink. This is done by adding the graphene flakes in large quantities to a solvent, creating the ink that can be used in printers.

This ink has many potential applications. A low-cost, printable ink could create educational opportunities for students without access to more advanced materials, especially students in developing countries. Many schools already have inkjet printers, so with the development of software for modeling the printable circuits, students would be able to print their own extremely complex circuits on paper, and then design and their own electronic projects with them. This could get more students interested in science, technology, engineering, and math (STEM) at a younger age by allowing them to do hands-on electronics projects at a low cost.

Graphene is one of the most versatile materials, and this is just one of the many potential applications we could see in the future. Graphene also can be integrated into computer processors, and any materials that need to be extremely strong. Once manufacturing methods become more polished, and the price becomes cheaper, graphene could become one of the most influential materials ever discovered.


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