Biomedical Engineering Reference
In-Depth Information
scientist at the University of Tokyo, in his work titled
On the Basic Concept of Nanotechnology
.
He described extra-high precision and ultrafine dimensional structures, and also expected improve-
ments in integrated circuits and devices of mechanical, optoelectronic, and computer memory appli-
cations (Taniguchi 1974). This is called the “top-down” approach (of carving small structures from
larger ones) (Thassu et al. 2007).
The creation of the scanning tunneling microscope by Gerd Binnig and Heinrich Rohrer in 1981,
from IBM Zurich Laboratories, rendered a breakthrough by allowing visualizations on a nanosized
scale. Further, the invention of the atomic force microscope (AFM) in 1986 made possible the
imaging of structures on an atomic scale. In 1986, another scientist, K. Eric Drexler, in his topic
titled
Engines of Creation
, argued about the future of nanotechnology, specifically the design of
larger structures from their atomic and molecular components, known as the “bottom-up approach”
(Drexler 1986). He also offered thoughts for “molecular nanotechnology,” which is the self-assem-
bly of particles into an ordered and functional structure.
Another major advance in the field of nanotechnology was established in 1985, when Harry Kroto,
Robert Curl, and Richard Smalley developed a new form of carbon known as “fullerenes” (or “bucky-
balls”), a single molecule containing 60 carbon atoms arranged in the shape of a soccer ball. This
invention led to a Nobel Prize in Chemistry in 1996. In 2000, this new area of research received recog-
nition from the government when former President Bill Clinton launched the National Nanotechnology
Initiative (NNI) to promote research and development in nanotechnology. NNI defines research and
development in nanotechnology as that on the 1-100 nm range scale to create systems with novel
properties that have the capacity to function on the atomic scale (Thomas and Sayre 2005). Thus,
nanotechnology aims to design the formulation of structures, devices, and systems by controlling the
shape and size at a nanometer range (Varshney 2012). Today, nanotechnology has progressed into an
extensive field of science, with multibillion dollar investments from the public and private sectors.
Along with this comes the potential to generate multitrillion dollar industries in the coming decades
with an enormous potential to benefit many more applications and areas of research.
1.2 NANOMATERIALS
The history of nanomaterials (NMs) is perhaps as old as that of the universe, as nanostructures were
formed in its near beginning. From the dawn of mankind, NPs were produced from fires used by
early humans (Alagarasi 2011). The scientific community caught on to NMs much later.
A nanometer is one millionth of a millimeter, about 100,000 times smaller than the diameter of
human hair. NMs are important because, at this scale, exclusive optical, magnetic, and electrical
properties emerge, among others. These characteristics have great application potentials in elec-
tronics, medicine, and other fields. Owing to coatings or surface modifications, NMs demonstrate
biocompatibility through interacting with living cells.
NMs are the foundation stones of nanoscience and nanotechnology, a large and interdisciplin-
ary area of research and development that has been explosively developing globally in the past few
years. It has the potential to revolutionize the approach in which NMs are developed, and the range
and nature of functionalities that can be accessed. It has a significant commercial impact, which will
continue growing in the future.
Modified NMs are resources fabricated at the nanometer scale to benefit from small sizes and
novel characteristics, normally not found in their conventional, bulk counterparts. These charac-
teristics are enhanced relative surface areas and new quantum effects. NMs encompass a higher
surface area to volume ratio than their conventional forms, which can lead to superior chemical
reactivities and also have an effect on their strength. Moreover, at the nanorange scale, quantum
effects become much more important in determining the material's properties, leading to new opti-
cal, electrical, and magnetic characters. The range of NM commercial products available today is
very broad, including sunscreens, wrinkle-free textiles, stain-resistant goods, cosmetics, electron-
ics, paints, and varnishes (Alagarasi 2011).
