Since the 2000s, nanotechnology has been used to improve consumer products ranging from wrinkle cream
to stain resistant clothing. A more important aspect of nanotechnology involves "nanonetworks." A nanonetwork has the same functional capabilities as a full size LAN, yet it is so small that hundreds of these networks could fit
on the head of a pin.
To most people, this sounds like science fiction. In this exclusive WaveLengths article, we'll explain why the introduction of nanonetworks is just around the corner. We'll also reveal how these diminutive networks will be interfaced with full-scale communication networks. Finally, we'll also learn about nanobots, a key component in nanonetworks.
Nano in a NutshellNanotechnology is relatively new and still a little squirrely. It involves manipulating matter on the molecular and atomic levels, which can sometimes produce unintended results. This is due to two factors:
- Nanoparticles are 1–100 nanometers in size which is the size threshold at which quantum physics can affect matter in unexpected ways.
- Nanoparticles have a large surface area relative to their weight. This can make them more reactive with elements in the environment, which can also produce unexpected results.
We don't yet know all of the health and safety implications that nanoparticles present, although these issues are beginning to be addressed. It is hoped that the benefits of nanotechnology will outweigh any risks.
Today, nanotechnology is progressing far beyond its initial use as a product enhancement. The U.S. has taken the lead in developingnanotechnology, which is nowa top priority for countries worldwide.
Nanonetworks The Ultimate GoalNanonetworks, the main subjectof this article, involves the coordination and control of nano-scale machines. When such machines are programmed to do a specialized task, such as detecting and killing cancer cells, they are called nanobots. Nanobots will typically work together within a distributed nanonetwork that can include thousands or millions of selfreplicating nanobots that share a common mission.
Nature's NanobotsIn recent years, researchers began to understand how living cells and microorganisms function and communicate with one another. The smallest of these organisms are in fact nano-sized creatures that are only 20–50 nanometers in diameter. Scientists are striving to create nanobots of their own that emulate the mobility and communication ability of microorganisms. Besides attacking cancer cells, specially designed nanobots could be programmed to clean up polluted environments and solve hundreds of other problems that plague society today.
Building a Better NanobotEssentially, there are two ways that nanomachine components can be made from scratch. Options include: Build from the Bottom Up Tools already exist that enable scientists to move individual atoms and molecules into position where attractive forces hold them in place.
Build from the Top Down This process involves making full size objects and applying heat or chemical processes that shrink them down to micro size or smaller. For example, circuits can be printed onto special materials that do not distort when shrunk.
Communication ProtocolsThere are a number of ways to achieve communications between nanomachines within a distributed nanonetwork. These include:
In nanonetworks, the close proximity of components allow for more direct exchange of information via message carrying molecules. This is similar to the methods used by adjacent cells within our bodies to communicate with one another. Molecular communication can also occur between distant cells via neural networks and blood vessels.
Flow – In flow-based communication, the information carrying molecules are carried by a fluidic medium (e.g. liquid or air) along a defined pathway. An example of this is hormonal communication that occurs through the bloodstream within the human body.
Diffusion – In diffusion based communication, data is sent everywhere. Information is up for grabs to anyone or anything that has the correct decryption key. For example, pheromone molecules diffused in air are species-specific.
Walkway – In the walkway approach, information-carrying molecules are transported over predefined pathways by use of carrier substances. Many nano-scale objects can serve as carriers, provided they have mobility. Molecular motors and bacteria provide two possibilities.
Nanonetworks will be required to communicate with larger conventional networks. Connecting the two systems via "nano wires" might work, but such delicate components would make the connection tenuous at best.
Wireless communications may be the preferred way to interface the two systems, using graphenebased transceivers.
Nanonetworks are Close at HandGiven the complexity of assembling working machines at the nano-scale, some people feel that nanonetworks may be a decade or more away. However, WaveLengths predicts that we may see the first nanonetworks in as little two or three years.
Here's why: Researchers have been quietly mapping the communication "circuits" of living organisms, as well as their DNA. In our view, it's a pretty safe bet that they intend to use this information to reprogram existing biological entities (i.e. bacteria and viruses) rather than create complex nanobots from scratch. After all, these nano-scale organisms already have mobility, their own communication network, and they are self-replicating. For commercial applications, reprogramming microorganisms would provide the cheapest and fastest way to market.
Early Success!In one experiment, diseased laboratory animals were injected with nanobots that were "programmed" to find and destroy Hepatitis C viruses. The nanobots attacked with a vengeance and succeeded in reducing the disease by nearly 100%. Each nanobot had a gold nanoparticle "backbone" to which was attached a DNA oligonucleotide that helped it locate and destroy its target. With the success of these first nanobots, can nanonetworks be far behind?
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