M8A2 Science in Today’s World - Reflections
ROSNDO
Module8.docx
Module 8: Module Notes: What Is Nanotechnology?
Computer graphic of a molecular tube, an example of nanotechnology.
Each of the coloured spheres represents a single atom: carbon (blue), oxygen (red), and hydrogen (yellow).
Nanotechnology involves the construction of devices at the molecular level.
Start this module by becoming familiar with the contents of Nanotechnology: Big Things from a Tiny World
(Links to an external site.)
Links to an external site.
[PDF, file size 1016 KB] and NanoSense: Introduction to Nanoscience
(Links to an external site.)
Links to an external site.
[PDF, file size 3.34 MB].
Nanotechnology is the science and technology of small things – in particular, things that are less than 100nm in size. For example, one nanometer (nm) is about 3 atoms long; for comparison, a human hair is about 60-80,000 nanometers wide.
Scientists have discovered that materials at small dimensions can have significantly different properties than the same materials on a larger scale. If we can understand these differences and learn how to control the assembly of small structures, then there are endless possibilities for improved devices, structures, and materials.
Nanotechnology is a highly interdisciplinary area of science. It is at the intersection of chemistry, physics, biology, and all areas of engineering. Most scientists and engineers agree that nanotechnology means:
The objects being studied are small (100 nanometers or less);
The objects have unique properties because of their small size;
Scientists and engineers can control the structure and composition on the nanometer scale in order to control the object’s properties; and
Scientists and engineers also have positional control. Molecules and atoms can be properly positioned with respect to one another, as we have done with large structures (NanoSense).
Nanostructures—objects with nanometer scale features—are not new. There are many natural nanoscale materials that have unique properties, particularly because of the nanoscale features. There are many examples of nanostructures in nature in the way that plants and animals have evolved. Scientists and engineers have begun to understand and control nanostructures and their properties to make new, functional materials and devices. Many things in our future will be based on engineered nanomaterials and devices.
Most of our devices and objects are constructed by starting with large pieces of materials and molding or shaping them to the desired size. Nanotechnology is different, in that devices and objects can be constructed by starting at the atomic level, building materials and structures atom by atom. The term self-assembly is used to describe the process of using the forces of nature to assemble nanostructures. Nanomaterials created this way have already resulted in a number of consumer products.
These materials have unique properties because of their small size. At the nanoscale, properties of materials behave differently and are said to behave according to atomic and molecular rules. Researchers are using the unique properties of materials at this small scale to create new and exciting tools and products, which will change our lifestyle and economy.
Illustration demonstrating the effect of the increased surface area provided by nanostructured materials. The cube on the left is 1 cm square; the next cube is a 1 cm square made from 1 mm square cubes; finally, there is a cube made from 1 nm square cubes. The available surface area increases from 6 cm squared to 60 cm squared to 60 million cm squared.
In this course, we have studied a great many areas of science. In all of these and others, nanotechnology can have a significant impact, making products faster, lighter, stronger, safer, and cleaner. Here are a few examples:
Transportation: The hulls of airplanes are currently made from metal, yet diamond has a strength-to-weight ratio over 50 times that of the aluminum used for airplanes. Today, diamond is expensive, we cannot make it in the shapes we want, and it shatters. Nanotechnology allows us to make shatterproof diamond inexpensively in exactly the shapes we want because of positional control. Using nanostructured diamonds, a Boeing 747 whose unloaded weight would be 50 times lighter could be just as strong as the current model.
Solar energy: Nanotechnology can help cut costs of solar cells and the equipment needed to place them in homes and businesses, making solar power economical. Engineers would not need to make new or improved solar cells: Simply making inexpensively what we already know how to make (expensively) would move solar power into the mainstream.
Medical diagnostics and therapeutics:Surgical tools the size of molecules with molecular level precision could let us directly heal, at the molecular and cellular level, some of the root causes of disease and poor health.
Scientists and engineers cannot say for sure how long it will take for these and other nano systems to be used in our daily lives; however, if we pursue nanotechnology with a sense of purpose, molecular manufacturing will happen sooner. The experts think we will have to develop the nano – or molecular – manufacturing technology this decade in order to keep pace with our technology trends and needs. Scientists now know there is no law of nature that can keep us from developing nanotechnologies. A large-scale coordinated effort of many scientists and engineers will be required to stay on task.
Nanotechnology offers the promise of revolutionizing the tools and products that are part of our daily lives. The activities in this module will introduce the principles and applications of this exciting area at the intersection of science and engineering.
