[Hplusroadmap] Fwd: C-R-Newsletter #62: March 31, 2008

[Bryan Bishop]

----------  Forwarded Message  ----------

Subject: C-R-Newsletter #62: March 31, 2008
Date: Monday 31 March 2008
From: CRN Newsletter <newsletter at crnano.org>
To: CRN Newsletter <newsletter at crnano.org>


To read this on the Web, with nice formatting and hyperlinks, go to 
http://crnano.org/archive08.htm#62 

CONTENTS

- Powerful Nanoscale Computer Created
- More Enabling Technologies
- Visions of the Future
- Empowering Hope
- Disruptive Nanotechnology
- Religion & Nanotech
- New Nano TV Show
- Debating CRN's Scope
- Archiving Nanotech Interviews
- Guest Science Essay: Atomic Force Microscopy

To keep up with all the latest CRN and nanotech activity on a daily 
basis, be sure to check our Responsible Nanotechnology weblog at 
http://CRNano.typepad.com/ 

========== 

Powerful Nanoscale Computer Created
 
A potentially powerful new form of nanoscale computing [1] has been 
developed by scientists in Japan. BBC News [2] describes the 
development as a "tiny chemical 'brain' which could one day act as a 
remote control for swarms of nano-machines." The innovative device is 
made of duroquinone [3], a compound composed of carbon, hydrogen, and 
oxygen, which suggests that it might become a key component of an 
early-generation nanofactory [4]. MSNBC has an excellent article online 
[5] about the new computing technique and also offers an interesting 
video [6] to illustrate it. 

[1] http://tinyurl.com/29lpjj
[2] http://news.bbc.co.uk/2/7288426.stm
[3] http://tinyurl.com/2hd2q3
[4] http://www.crnano.org/bootstrap.htm
[5] http://tinyurl.com/2yxz6s
[6] http://tinyurl.com/24xp7p

 
More Enabling Technologies
 
CRN has been tracking numerous examples of enabling technologies [1] 
that may help pave the way for molecular manufacturing [2]. Over the 
last several weeks, these are some of the most interesting that we've 
found:

* Using DNA nanotechnology to build three-dimensional crystals [3]
* Remote-control DNA 'pistons' could power tiny robots [4]
* 'Nanosculptors' carve atom by atom [5]

[1] http://tinyurl.com/ynwcp2
[2] http://www.crnano.org/developing.htm
[3] http://www.foresight.org/nanodot/?p=2650
[4] http://tinyurl.com/2jy6el
[5] http://www.nanowerk.com/spotlight/spotid=4444.php


Visions of the Future

A new three-part TV series [1] from the BBC features leading theoretical 
physicist and futurist Dr Michio Kaku exploring the cutting edge of 
science. In part three of the series, Kaku says: 

"Amazingly, we can now manipulate individual atoms. We can pick them up, 
move them around, and even play with them. Today we can manipulate 
individual atoms, but this is just the beginning of a journey -- a 
journey which will ultimately give us the power to manipulate the very 
stuff of our universe: matter itself. We are on the brink of a 
revolution which will give us control -- exquisite control -- of our 
physical world."

Part three covers, among other things, bloodstream nanobots, space 
elevators, invisibility, teleportation, and military nanobots. A good 
deal of time is also spent presenting the concept of a desktop 
nanofactory. You can watch the whole series online [2,3,4].

[1] http://tinyurl.com/2pgdc5
[2] http://tinyurl.com/2mro8g
[3] http://tinyurl.com/2of4jv
[4] http://tinyurl.com/2mejy5


Empowering Hope

CRN's latest monthly column [1] for the popular Nanotechnology Now web 
portal is by our Director of Impacts Analysis, Jamais Cascio [2]. His 
article is titled "Super-Empowered Hopeful Individuals." Here is the 
abstract:

> Most discussions of the benefits of molecular manufacturing tend to 
focus either on broad social advances or individual desires that such a 
transformative technology may be able to satisfy. These are surely 
useful ways of thinking about a nanotech-enabled world. But what if 
this model misses another category, one that may be less noticeable 
precisely because we pay so much attention to its opposite?

We hope you'll read all our columns [3], offer feedback, and tell others 
about them too.

[1] http://www.nanotech-now.com/columns/?article=181
[2] http://www.crnano.org/about_us.htm#Principals
[3] http://www.nanotech-now.com/columns/?column=21


Disruptive Nanotechnology

A California newspaper, Palo Alto Weekly, has a cover story on 
nanotechnology, a long article that covers both current work in 
nanoscale technologies and the more futuristic possibilities of 
molecular manufacturing. CRN executive director Mike Treder was 
interviewed for the piece and quoted extensively in it. You can read 
the whole article online [1].

[1] http://tinyurl.com/2vlskp


Religion & Nanotech

In February, the University of Wisconsin-Madison released the results of 
a study on religion and nanotechnology. A press release [1] about their 
findings deals with the question: "Is nanotechnology morally 
acceptable?"

The article generated significant coverage online, including numerous 
comments [2] at CRN's blog. 

[1] http://tinyurl.com/2y58oj
[2] http://tinyurl.com/yr583j


New Nano TV Show

"Nanotechnology: The Power of Small" [1] is coming to U.S. public 
television stations in April 2008. The program, produced by the Fred 
Friendly Seminars and sponsored by the National Science Foundation, 
comprises three episodes:

1. PRIVACY - Watching You Watching Me
2. HEALTH - Forever Young
3. ENVIRONMENT - Clean, Green, and Unseen

CRN's Mike Treder was asked by the makers of the program to preview it 
and give them a reaction. Afterwards, he wrote [2]:

> Imagine yourself sitting in an audience at a university symposium and 
watching a large and diverse panel of experts from science, business, 
and activist groups debate the merits of advanced nanotechnology. 
That's exactly the experience you'll have in viewing this program. 
Unlike many so-called science specials on TV these days, "The Power of 
Small" takes its subject seriously and treats its audience as 
intelligent, discriminating adults. Thankfully, there are no flashy 
graphics, no distracting camera tricks or special effects; just smart, 
thoughtful people led by a capable moderator discussing provocative 
issues. Overall, I was quite impressed.

[1] http://powerofsmall.org/index.php
[2] http://tinyurl.com/2ym8jb


Debating CRN's Scope

Although we call ourselves the Center for Responsible Nanotechnology, 
we've confined our focus to a specific, powerful application of 
advanced nanotechnology known as molecular manufacturing [1]. However, 
not everyone believes that CRN should continue concentrating only on 
molecular manufacturing and its implications. We've recently had a good 
long discussion on our blog [2] about whether, how, and why CRN should 
consider expanding our scope. Please let us know if you have anything 
to add!

[1] http://www.crnano.org/essays05.htm#2
[2] http://tinyurl.com/2nbt6o


Archiving Nanotech Interviews

Sander Olson is one of the original developers of the NanoApex and 
NanoMagazine websites. Over the years, Sander has conducted numerous 
conversations with notable figures working in or commenting on the 
field of nanotechnology. Since the acquisition of his sites in 2005 by 
the International Small Technology Network, many of Sander's interviews 
have not been available on the web.

To correct this, CRN created a page [1] on our main website as an 
archive of his interviews. In recent weeks, we've added Sander's 
in-depth talks with Jeff Chinn, Hugo DeGaris, Jack Dunietz, Glenn 
Fishbine, J. Storrs Hall, Jeffrey Harrow, Gary Mezo, Jagdish Narayan, 
and James Talton. 

[1] http://www.crnano.org/interviews.index.htm


Guest Science Essay: Atomic Force Microscopy 
By Michael Berger, editor-in-chief of Nanowerk
 
(This article was originally published on March 10, 2008, at 
Nanowerk.com [1] and is reprinted here by permission.)

Whenever you read an article about nano this or nano that, chances are 
you come across a large number of confusing three-letter acronyms - 
AFM, SFM, SEM, TEM, SPM, FIB, CNT and so on. It seems scientists earn 
extra kudos when they come up with a new three-letter combination. One 
of the most important acronyms in nanotechnology is AFM - Atomic Force 
Microscopy. This instrument has become the most widely used tool for 
imaging, measuring and manipulating matter at the nanoscale and in turn 
has inspired a variety of other scanning probe techniques.

Originally the AFM was used to image the topography of surfaces, but by 
modifying the tip it is possible to measure other quantities (for 
example, electric and magnetic properties, chemical potentials, 
friction and so on), and also to perform various types of spectroscopy 
and analysis. Today we take a look at one of the instruments that has 
it all made possible. So far, over 20,000 AFM-related papers have been 
published; over 500 patents were issued related to various forms of 
scanning probe microscopes (SPM); several dozen companies are involved 
in manufacturing SPM and related instruments, with an annual worldwide 
turnover of $250-300 million, and approx. 10,000 commercial systems 
sold (not counting a significant number of home-built systems [2]).

To put the AFM in its context: The reason why nanosciences and 
nanotechnologies have taken off with such amazing force over the past 
20 years is because our ongoing quest for miniaturization has resulted 
in tools such as the AFM (invented in 1986) or its precursor, the 
scanning tunneling microscope (STM; invented in 1982. IBM has a website 
with a gallery of STM images here [3]). Combined with refined processes 
such as electron beam lithography, this allowed scientists to 
deliberately manipulate and manufacture nanostructures, something that 
wasn't possible before.

These engineered nanomaterials, either by way of a top-down approach (a 
bulk material is reduced in size to nanoscale particles) or a bottom-up 
approach (larger structures are built or grown atom by atom or molecule 
by molecule), go beyond just a further step in miniaturization. They 
have broken a physical barrier beyond, or rather: below, which the 
standard laws of physics are replaced by what is called "quantum 
effects". Any material reduced to the nanoscale can suddenly show very 
different properties than to what it shows on a macro- and larger 
scale. For instance, opaque substances become transparent (copper); 
inert materials become catalysts (platinum); stable materials turn 
combustible (aluminum); solids turn into liquids at room temperature 
(gold); insulators become conductors (silicon).

A second important aspect of the nanoscale is that the smaller 
nanoparticles get the larger their relative surface area becomes. The 
larger the relative surface area, the more reactive a particle becomes 
with regard to other substances. The fascination with nanotechnology 
stems from these unique quantum and surface phenomena that matter 
exhibits at the nanoscale, enabling novel applications and interesting 
materials.

But without the AFM, all this wouldn't be happening.

The term microscope in the name is actually a misnomer because it 
implies looking, while in fact the information is gathered by feeling 
the surface with a mechanical probe. The operation principle of an AFM 
is based on three key elements:

1) an atomically sharp tip (the "probe"), placed at the end of a 
flexible cantilever beam, that is brought into physical contact with 
the surface of a sample. The cantilever beam deflects in proportion to 
the force of interaction;

2) a piezoelectric transducer to facilitate positioning and scanning the 
probe in three dimensions over the sample with very precise movements; 
and

3) a feedback system to detect the interaction of the probe with the 
sample.

Scanning across the surface, the sharp tip follows the bumps and grooves 
formed by the atoms on the surface. By monitoring the deflections of 
the flexible cantilever beam one can generate a topography of the 
surface.

This principle has been the basis for one of the most important 
nanoscience tools and allowed the visualization of nanoscale objects 
where conventional optics cannot resolve them due to the wave nature of 
light.

A recently published article in the Encyclopedia of Life Sciences, 
written by Martijn de Jager and John van Noort, both from the 
University of Leiden in The Netherlands, gives an excellent overview of 
Atomic Force Microscopy [4] and its applications in life sciences. 
Below we are summarizing some of the key information from this article.

The AFM can be operated in a number of modes, depending on the 
application but four modes are most commonly used for AFM imaging: 
contact mode (or constant height mode), where the deflection of the 
cantilever is directly used as a measure for the height of the tip and 
the normal force applied to the sample scales directly with its height. 
In constant force mode, the normal force the cantilever deflection 
under scanning reflects repulsive forces acting upon the tip, and at 
sufficiently small scanning velocities the force feedback can reduce 
the normal force. Tapping mode (or noncontact mode), where the tip is 
vibrated (oscillating at its resonance frequency) perpendicular to the 
specimen plane to avoid gouging the specimen as the tip is scanned 
laterally and the lateral forces are reduced. In a fourth mode of 
scanning, the force-distance mode, the tip is brought to the sample at 
frequencies far below the resonance frequency of the cantilever while 
at the same time the deflection is recorded. This allows one to measure 
the local interaction as a function of the tip-sample distance.

As de Jager and van Noort write in their article, large numbers of 
various biological samples, including cells, cell compartments and 
biomolecules, have been studied with AFM. "In some of these studies, 
AFM is used as a plain imaging tool to investigate the topography of 
immobilized and/or fixed samples, complementing existing methods such 
as electron microscopy, with the advantage that sample preparation is 
generally more straightforward. For other experiments, the use of AFM 
is a prerequisite to look at nonfixed materials and even their dynamics 
in aqueous environment. Besides its imaging capabilities AFM is 
becoming increasingly important as a nanomanipulation tool. The 
single-molecule analysis of interaction forces, elasticity and tertiary 
protein structure in intact biological materials is uniquely possible 
using AFM."

Introducing this vast body of research is beyond the scope of any 
article. Let's just take a look at two examples illustrated in the 
paper:

Imaging Cells

"AFM imaging of living cells provides a direct measurement of cell 
morphology with nanometer resolution in three dimensions. Because of 
its noninvasive nature and the absence of fixation and staining, even 
dynamic processes like exocytosis, infection by virus particles and 
budding of enveloped viruses have been successfully visualized in 
successive scans. Owing to the high elasticity of the cell membrane, 
the tip can deeply indent the cell without disrupting the membrane. 
Making use of this effect, even submembraneous structures such as 
cytoskeletal elements or organelles like transport vesicles can be 
revealed. However, due to the elasticity of the cell the contact area 
between the tip and the sample increases with increasing applied force. 
The elastic modulus of living cells varies between 10 and 100 kPa, 
which results in a tip sample contact area of 50-100nm in the softest 
region of the cell. Therefore, the (sub-) nanometer resolution that is 
routinely achieved on more rigid samples cannot be achieved on 
membranes of intact cells."

Structure, Function and Interaction of Single DNA and Protein Molecules

"Besides the analysis of cells and cell membranes, AFM-based methods to 
study purified single molecules like proteins, deoxyribonucleic acid 
(DNA) and ribonucleic acid (RNA) have developed rapidly in the past 
decade. Unique details on the mechanism and function of DNA- and RNA 
metabolizing proteins can directly be obtained by quantification of the 
number, position, volume and shape of protein molecules on their 
substrate. Like other single molecule techniques all individual 
instances of the entire population of structures are revealed, also 
showing rare but important species. Further insights in the mechanism 
of a reaction can be obtained from image analysis by measuring 
parameters such as protein-induced DNA bending, wrapping and looping. 
Besides topography imaging, force spectroscopy has been successful in 
unraveling tertiary structure in proteins, RNA and other polymers."

Although it already is an essential tool for structural analysis and 
manipulation of complex macromolecules and living cells, it is to be 
expected that AFM-based applications will be further extended in the 
future. Technical developments will advance the AFM system itself, by 
improvement of resolution, image rate, sensitivity and functionality. A 
combination with complementary techniques will fill in some limitations 
of AFM.

To fully exploit the potential of AFM to study functional biomolecules 
and their interactions, de Jager and van Noort say that video 
microscopy would be needed to capture dynamic events. "Currently, the 
scan rate is limited by the mechanical response of the cantilever and 
the piezo. Smaller cantilevers will result in higher resonance 
frequencies, allowing faster scanning rates. By reducing the size of 
the cantilevers one order of magnitude, the frame rate can be reduced 
from typically a minute down to video rate, allowing the study of a 
significantly larger range of biomolecular processes."

The two researchers expect the most important developments for the tip 
itself. "Image resolution in all modes is dependent on tip geometry. 
The reduction of tip size, increase of its aspect ratio and its 
resistance to wear as a result of scanning will have a considerable 
impact on all AFM applications."

For instance, researchers at Harvard and Stanford universities have 
developed a specially designed AFM cantilever tip [5], the torsional 
harmonic cantilever (THC), which offers orders of magnitude 
improvements in temporal resolution, spatial resolution, indentation 
and mechanical loading compared to conventional tools. 

With high operating speed, increased force sensitivity and excellent 
lateral resolution, this tool facilitates practical mapping of 
nanomechanical properties.


[1] http://www.nanowerk.com/spotlight/spotid=4876.php
[2] http://www.nanowerk.com/spotlight/spotid=2304.php
[3] http://www.almaden.ibm.com/vis/stm/gallery.html
[4] http://tinyurl.com/2hc5n4
[5] http://www.nanowerk.com/spotlight/spotid=2334.php

================= 
 
The Center for Responsible Nanotechnology(TM) is an affiliate of World 
Care(R), an international, non-profit, 501(c)(3) organization. All 
donations to CRN are handled through World Care. The opinions expressed 
by CRN do not necessarily reflect those of World Care. 

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