Microsoft Word Kurzweil, Ray The Singularity Is Near doc

Nanosystems
, each aspect of Drexler's conceptual designs has been 
validated through additional design proposals.
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supercomputer simulations, and, most important, actual construction 
of related molecular machines. Boston College chemistry professor T. Ross Kelly reported that he constructed a 
chemically powered nanomotor out of seventy-eight atoms.
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A biomolecular research group headed by Carlo 
Montemagno created an ATP-fueled nanomotor.
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Another molecule-sized motor fueled by solar energy was created 
out of fifty-eight atoms by Ben Feringa at the University of Groningen in the Netherlands.
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Similar progress has been 
made on other molecular-scale mechanical components such as gears, rotors, and levers. Systems demonstrating the 
use of chemical energy and acoustic energy (as originally described by Drexler) have been designed, simulated, and 
actually constructed. Substantial progress has also been made in developing various types of electronic components 
from molecular-scale devices, particularly in the area of carbon nanotubes, an area that Richard Smalley has 
pioneered. 
Nanotubes are also proving to be very versatile as a structural component. A conveyor belt constructed out of 
nanotubes was demonstrated recently by scientists at Lawrence Berkeley National Laboratory.
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The nanoscale 
conveyor belt was used to transport tiny indium particles from one location to another, although the technique could be 
adapted to move a variety of molecule-sized objects. By controlling an electrical current applied to the device, the 
direction and velocity of movement can be modulated. "It's the equivalent of turning a knob ... and taking macroscale 
control of nanoscale mass transport," said Chris Regan, one of the designers. "And it's reversible: we can change the 
current's polarity and drive the indium back to its original position." The ability to rapidly shuttle molecule-sized 
building blocks to precise locations is a key step toward building molecular assembly lines. 
A study conducted for NASA by General Dynamics has demonstrated the feasibility of self-replicating nanoscale 
machines.
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Using computer simulations, the researchers showed that molecularly precise robots called kinematic 
cellular automata, built from reconfigurable molecular modules, were capable of reproducing themselves. The designs 
also used the broadcast architecture, which established the feasibility of this safer form of self-replication. 

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DNA is proving to be as versatile as nanotubes for building molecular structures. DNA's proclivity to link up with 
itself makes it a useful structural component. Future designs may combine this attribute as well as its capacity for 
storing information. Both nanotubes and DNA have outstanding properties for information storage and logical control, 
as well as for building strong three-dimensional structures. 
A research team at Ludwig Maximilians University in Munich has built a "DNA hand" that can select one of 
several proteins, bind to it, and then release it upon command.
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Important steps in creating a DNA assembler 
mechanism akin to the ribosome were demonstrated recently by nanotechnology researchers Shiping Liao and Nadrian 
Seeman.
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Grasping and letting go of molecular objects in a controlled manner is another important enabling capability 
for molecular nanotechnology assembly. 
Scientists at the Scripps Research Institute demonstrated the ability to create DNA building blocks by generating 
many copies of a 1,669-nucleotide strand of DNA that had carefully placed self-complementary regions.
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The strands 
self-assembled spontaneously into rigid octahedrons, which could be used as blocks for elaborate three-dimensional 
structures. Another application of this process could be to employ the octahedrons as compartments to deliver proteins, 
which Gerald F. Joyce, one of the Scripps researchers, called a "virus in reverse." Viruses, which are also self-
assembling, usually have outer shells of protein with DNA (or RNA) on the inside. "With this," Joyce points out, "you 
could in principle have DNA on the outside and proteins on the inside." 
A particularly impressive demonstration of a nanoscale device constructed from DNA is a tiny biped robot that 
can walk on legs that are ten nanometers long.
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Both the legs and the walking track are built from DNA, again chosen 
for the molecule's ability to attach and detach itself in a controlled manner. The nanorobot, a project of chemistry 
professors Nadrian Seeman and William Sherman of New York University, walks by detaching its legs from the track, 
moving down it, and then reattaching its legs to the track. The project is another impressive demonstration of the 
ability of nanoscale machines to execute precise maneuvers. 
An alternate method of designing nanobots is to learn from nature. Nanotechnologist Michael Simpson of Oak 
Ridge National Laboratory describes the possibility of exploiting bacteria "as ready-made machine[s]." Bacteria, 
which are natural nanobot-size objects, are able to move, swim, and pump liquids.
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Linda Turner, a scientist at the 
Rowland Institute at Harvard, has focused on their thread-size arms, called fimbriae, which are able to perform a wide 
variety of tasks, including carrying other nanoscale objects and mixing fluids. Another approach is to use only parts of 
bacteria. A research group headed by Viola Vogel at the University of Washington built a system using just the limbs 
of 
E. coli
bacteria that was able to sort out nanoscale beads of different sizes. Since bacteria are natural nanoscale 
systems that can perform a wide variety of functions, the ultimate goal of this research will be to reverse engineer the 
bacteria so that the same design principles can be applied to our own nanobot designs.