November 21, 2013
First we invent it, then we make it smaller. That seems to be the eternal trend with technological advancement. From the stereo to the portable cd player down to the iPod, technology is shrinking, and that is great. We like things small. If something is small, it is easier to carry or to incorporate into our attire. I remember having a giant pair of headphones as a kid that not only covered my ears, but much of my head. Now, as I write this, I am listening to music through a pair of ear-buds so not to wake up my roommate. The original computers were massive, taking up entire rooms, and had so much less processing power than the phones we carry in our pockets today or the tablets we carry around with us. The Nintendo 3DS I recently acquired is so much smaller than my original Nintendo I got when I was six, yet while that only had 8-bit graphics, this little device is fully 3D and can play some very incredible games (Pokemon X/Y, anyone?). So, all of this warrants the question, just how small are we able to go?
Recently, a team of Colombia Engineering professors led by Professor James Hone and Professor Kenneth Shepard have used the special properties of graphene to create the worlds smallest FM radio transmitter. Graphene is the strongest material known to man. Made up of a single atomic layer of carbon – meaning that it is only as thick as a single atom – has electrical properties similar, and even superior, to silicon, which is used in the circuitry found in modern electronic devices. These two properties make graphene perfect for NEMS, or nanoelectromechanical systems, which are smaller versions of the systems used for sensing vibration and acceleration, such as what is used in a smartphone, tablet, or Nintendo 3DS to figure out when it is being tilted or turned. Using graphene, the team created a nanomechanical version of a VCO (voltage controlled oscillator), which is used to generate frequency-modulated signals, or FM radio broadcasting. They used low-frequency musical signals to send the carrier signal from the graphene and retrieved them using an ordinary FM receiver.
According to Professor Shepard “Due to the continuous shrinking of electrical circuits known as ‘Moore’s Law’, today’s cell phones have more computing power than systems that used to occupy entire rooms. However, some types of devices, particularly those involved in creating and processing radio-frequency signals, are much harder to miniaturize. These ‘off-chip’ components take up a lot of space and electrical power. In addition, most of these components cannot be easily tuned in frequency, requiring multiple copies to cover the range of frequencies used for wireless communication.” Shepard and Hone’s graphene NEMS addresses these problems, as they are both compact and easily integrated into other electronics. In addition, their frequencies can be tuned over a very wide range thanks to graphene’s tremendous mechanical strength. Currently, the team is a long way from everyday applications of this new technology, but they are currently working on improving the performance of the graphene oscillators so that they generate lower noise and attempting to demonstrate how they can be integrated into existing technology along with silicon circuits.
And so, once again, technology grows smaller.
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