Biomedical Engineering Reference
In-Depth Information
Nanotechnology is generally defi ned as “the engineering of functional systems at
the molecular scale” [
1
-
5
]. In other words, it is manipulation of matter at the atomic
and molecular scale to create materials with remarkably varied and new properties
with huge potential in many sectors, ranging from healthcare to construction of
electronics. In medicine, it promises to revolutionize drug delivery, gene therapy,
diagnostics and many areas of research, development and clinical application.
1. We should be able to place every atom in exactly the right position.
2. We should be able to build anything that complies with the laws of physics, as
long as we can understand it at a molecular or atomic level.
3. And perhaps, the one that drives most research in this fi eld is the idea that the
costs of manufacture should not be much higher than the costs of only the materials
and energy required to put the product together [
8
-
14
].
Geometry
and
minimization
are at the heart of nanotechnology. Look only into
viruses! As of known nano-size, they have mostly stable icosahedron geometric shapes
while in non-living state (out of the host) with their crystal DNA within the nano-
particle, becoming alive during interaction with the host cells [
2
,
3
]. The interaction
involves their DNA/RNA replication which involves the “borrowing” of enzymes for
that particular procedure within the host cell.
There are also certain names already given to the particular structures emerging
from nano-technological approaches [
1
,
4
-
11
] such as:
Nanotubes
which are elongated carbon forms with one or more concentric
polygonal cylinders. They are grown from carbon under high-temperature,
electrically-charged conditions. Due to their geometric similarity to the geodesic
domes designed by the greatest thinker of twentieth century, R. Buckminster Fuller,
nanotubes are furthermore called “
Bucky tubes
”.
Nanohexagons
are nanotubes with hexagonal ends.
Nanoctagons
are nanotubes
with octagonal ends.
Nanocircles
are circular nanostructures and
nanospheres
are
spherical nanostructures.
Nanoshells
are hollow nanospheres, and lately used in
medical purposes [
15
-
19
].
Within last decade, nanotechnology has moved from abstraction to reality with
the development of tools such as the:
Atomic Force Microscope (AFM),
Scanning Tunneling Microscope (STM), and the
Virtual Surface Profi ling Microscope (VSPM).
These microscopes do more than just let people view little materials. They also enable
manipulation of matter on a perspective of nanometers in a vacuum, liquid or gas.
AFM has a probe that creates three-dimensional images of specifi c atoms and
molecules at the nano-scale dimension as it moves across an object's outside. STMs
may etch surfaces and move particles on dimension of nanometers. VSPM digitiz-
ing the whole slide at high resolution, so that the viewer can zoom into areas and
structures of interest on the slide. It creates what we call a
digital slide
, or a virtual
slide, meaning that the user sees the same image in the screen as they would get if
they projected the microscope image onto the screen, but it's an electronic fi le.
All of these methods help us to visualize invisible at the “nano” level.
