The Tiniest Electric Motor in the
World 1. Scientists recently made public the
tiniest electric motor ever built. You could stuff hundreds of them into the
period at the end of this sentence. One day a similar engine might power a tiny
mechanical doctor that would travel through your body to remove your
disease. 2. The motor works by shuffling atoms between two
molten metal droplets (小滴) in a carbon nanotube. One droplet is even smaller
than the other. When a small electric current is applied to the droplets, atoms
slowly get out of the larger droplet and join the smaller one. The small droplet
grows—but never gets as big as the other droplet—and eventually bumps into the
large droplet. As they touch, the large droplet rapidly sops up the atoms it had
previously lost. This quick shift in energy produces a power stroke.
3. The technique exploits the fact that surface tension—the tendency of
atoms or molecules to resist separating—becomes more important at small scales.
Surface tension is the same thing that allows some insects to walk on
water. 4. Although the amount of energy produced is small—20
microwatts—it is quite impressive in relation to the tiny scale of the motor.
The whole setup is less than 200 nanometers on a side, or hundreds of times
smaller than the width of a human hair. If it could be scaled up to the size of
an automobile engine, it would be 100 million times more powerful than a Toyota
Camry’s 225 horsepower V6 engine. 5. In 1988, Professor Richard
Muller and colleagues made the first operating micrometer, which was 100 microns
across, or about the thickness of a human hair. In 2003, Zettl’s group created
the first nanoscale motor. In 2006, they built a nanoconveyor, which moves tiny
particles along like cars in a factory. 6. Nanotechnology
engineers try to mimic nature, building things atom by atom. Among other things,
nanomotors could be used in optical circuits to redirect light, a process called
optical switching. Futurists envision a day when nanomachines, powered by
nanomotors, travel inside your body to find disease and repair damaged
cells. A．An Introduction of a Toyota’s 225 Horsepower V6
Engine B．A Description of the Nanomotor in Terms of Power and
Size C．Surface Tension D．Previous Inventions
of Nanoscale Products E．The Working Principle of the
Nanomotor F．Possible Fields of Application in the Future A．remove disease
B．resist separating
C．shuffle between two molten metal droplets
D．power nanornachines
E．sop up molecules from the large droplet
F．transport nanoscale objects
Doctors envision that the nanomotor would travel through human bodies to ______.