- Materials & Industrial Technology
Nano Motors - Smallest Synthetic Engines Ever
How small of an engine can a man make, these days? How about the size of a molecule?
If you can excite a molecule to give off particles, and have it do so in a predictable cycle, then you’ve created a nano engine. Nano engines may be small, but their power output is insanely huge compared to man-made engines, when considering their size/output ratio. When you think of an atom bomb, and you realize that it is powerful because of the way the atomic forces are harnessed, then perhaps you can believe that a nano engine can have the same type of power output.
Berkeley Lab scientists have made such a nano-motor.1 It is 200 nanometers wide. A nanometer is one-billionth of a meter. Its power “density” is 100 million times greater than that of a V-6 engine. Note that I said “density,” and not output. If the nano-motor were enlarged to the size of an automobile engine, and still had the same power density, it would then output 100,000,000 times more power or energy than the V-6 engine. Its power is a product of surface tension, the same attractive force that gives body to a drop of water, or helps some insects to walk on water. “Surface tension becomes more important as objects become smaller, and at the nanoscale, it dominates,” says Chris Regan of Berkeley Lab’s Materials Sciences Division.
Different Types of Nano-engines
Oscillators: The motor pictured here is one of several in the works. Scientists have created a tube of carbon, 10,000 times thinner than a human hair. In or on that tube they place a molten droplet of a metal called indium. Next, they run a current through the nano tube. The current causes the droplet to give off atoms or particles, which travel along the tube. But they don’t get very far before they gather together to form their own droplet. This second droplet grows quickly. It grows to such a size that it soon touches the mother droplet. Because of surface tension, the second droplet is absorbed back into the first one, and the oscillation starts all over again.
Nanowires: Catalytic nanowires have a different metal at each end, such as gold and platinum. Placed in hydrogen peroxide, the platinum oxidizes the peroxide, and the gold reduces it to water. The reaction combines to propel the nanowire forward. When placed in an environment of silver ions, the wire moves much faster, thus serving as a detector of silver or other impurities found in water.2
Rotating Rotors: A gold chip is placed around a graphite (or carbon) tube. Inside that tube is another fixed tube of graphite. The outer tube serves as a bearing, so that the gold chip can rotate.3
Sliding Tuners or Indicators: Placing one carbon tube outside another does not cause a bond or connection. You can place a piece of metal on the outer tube to serve as an indicator when the outer tube moves. To move the outer tube, you heat one end of the fixed tube, and cool the other end. By controlling the temperature applications, you can control the lateral movement down to half a molecule accuracy.
Nano motors use very little friction, and can be run on very small levels of electricity, static eletricity, or other chemical or thermal sources. Therefore, they will be very efficient to run, and they likely will never wear out.
Here is a quote from the book pictured at the right: "There is a lot of empty space in our bones. Some nanotechnologists tell us that if we could inject pure diamond fibers into that empty space, bone strength would surpass steel. Through nanotechnology the rest of our bodies also could be infused with diamond fabric. Scientists have already calculated that this kind of diamond-based body reinforcement would have "G" force tolerance. In other words one could fall off a building and walk away unscathed."
Scientists have at least two objectives in nano technology: The first is to get the engines to reproduce - whether by themselves, or with the help of other nano-bots.4 The second is to find a way to power everyday industrial devices. Some target industries are: switches, solar light harvesters, DNA manipulators, blood vessel cleansers, bio sensors, cell phones, optics, digital pens and so on. There are even plans to create nano computers the size of a grain of sand. Some motors may be used to power nanobots placed in the bloodstream to seek out and repair damaged tissues in the human body.
Nano motors have earned the status of fact, not science fiction.5 In nature there already exists models available for study and inspiration.6 One is a cell which uses a similar-type motor for propulsion: it’s the vorticella cell, and it’s propulsion device is a coil or flagellum called a spasmoneme.7
Conclusion and Prediction Department
To every good thing there is a dark side. An instance of this happened in the world of computers and the information highways in which they took part: it is the computer virus. Just as a positive force can be had by developing and using nano-technology, an opposite darker side can also be developed and used. Readers, let’s always be mindful of the entities who will be developing this industry. Let’s study their character and motives. If there is anything that can be done to dissuade any evil tendencies in this field, then it is up to us to stamp it out at its inception. Let’s learn from history, and increase the chances of creating a better utopia by smothering evil before it takes root.
Notes (the following sources have also been used to collect information not notated):