Nanotechnology and Gray Goo
from page 72, December 2006 issue of Wired.
Nanotechnology
Nano machines are so named because they are designed to be very small, and the term nano relates to one-billionth of
some measurement, such as a millimeter.
Scientists are working on designing single-celled organisms to do work. These are some of the microscopic devices they
have developed.
Microbe Motor
The organism used to make a rotor spin is called Mycoplasma mobile.
These bacteria are coated with a vitamin, biotin, and moved onto a circular track. They race around the track in search
of food. The biotin coating on them sticks to an adhesive on the rotor blades which causes it to spin. At the time of
this writing, the rotor speed was two revolutions per minute. A use for these tiny motors could someday power small
robots, drive pumps, or generate electricity on a microscale. M. mobile eats sugar for energy.
Algal Packmule
Chlamydomonas reinhardtii is a photosensitive algae that, when a light is shined near it, drags tiny beads toward the
light for 8 inches at 200 microns per second or about 0.5 miles per hour. These cells could be used to move products
on a microscopic assembly line or purify polluted water.
Bacterial Electricians
Pelotomaculum thermopropionicum, Geobacter sulfurreducens, and other cells could lay electrical conduits. They excrete
protein nanowire that can form electrical grids. As of 2006, the US Navy was looking for nanowire to transfer energy in
fuel cells. These very thin cables could also be used to power tiny electrical devices.
Cellular Pump
A cardiac muscle cell beats, even when it is outside the heart. Many of these cells could be grown and used to pump
fluid in micro devices.
Gray Goo
In the future, these small machines could be programmed to attack and eradicate cancer cells, repair heart valves,
clean up oil spills, repair spinal cord injuries, and do many other tasks. A concentration of Millions or even billions
of these tiny machines that would be put to work, might appear to be a "gray goo" because an individual device would be
too small to be seen by the naked eye. Can you imagine your doctor recommending that you drink a gray goo of millions of
repair machines?
Although the machines described above are cellular-based, it is possible that future machines would be mechanical or
a hybrid cellular/mechanical design.