What is nanotechnology?
Nanotechnology is the science of the very small and involves the manipulation of matter at the atomic or molecular level. A nanometer is 100,000 times thinner than a strand of hair.
Nanotechnology has three important aspects: size, structure, and resulting novel properties.
Size: It takes about 3-10 atoms to span the length of a nanometer. In comparison, the diameter of a human hair is about 20,000 nanometers wide and a smoke particle is about 1,000 nanometers wide.
Structure: Nanotechnology is not just about the size of looking at very small things, it is about structure, or how things are put together, arranged, or assembled. It is the ability to work – observe, manipulate, and build – at the atomic or molecular level.
Novel Properties: Nanotechnology produces materials and systems that exhibit novel and significantly changed physical, chemical, and biological properties because of their size and structure. When a substance consists only of clusters of a few hundred atoms, the laws of quantum mechanics influence dramatic changes in its mechanical, optical, and electronic properties. These properties include improved catalysts, tunable photoactivity, and increased strength.
Is nanotechnology really something new?
Many things we are already familiar with are nanoscale and analogous to applications of nanotechnology. For instance, living organisms from bacteria to beetles rely on nanometer-sized protein machines that do everything from whipping flagella to flexing muscles. All biological cells are comprised of smart materials that self-assemble.
Nanometer-sized carbon (carbon black) that improves the mechanical properties of tires, nanometer silver particles that initiate photographic film development, and nanometer particles that are the basis of catalysts critical to the petrochemical industry have contributed to commercial products for many years. However, all of the above examples of technologies are not considered nanotechnology because they do not involve specific atomic manipulations to achieve desired properties and functions of materials or products. Nanotechnology does involve purposeful atomic manipulations and structural assembly to achieve predetermined properties and functions.
What kinds of structures are made on the nanoscale?
The structures of nanotechnology are important in how they are made and how their atoms are ordered. That is, a nanoparticle (a collection of tens to thousands of atoms measuring about 1-100 nanometers in diameter) is created atom by atom, and the size (and sometimes shape) of the particle is controlled by experimental conditions.
Nanocrystals: Nanocrystal is also used to describe these particles because the atoms within the particle are highly ordered or crystalline. A synthesized nanoparticle, however, is often called colloidal or a colloidal crystal because it is nanosized, and because it is typically dispersed or suspended in a stabilizing medium.
Nanolayers: Nanoparticles can also be arranged or assembled into ordered layers, or nanolayers. Such self-assembly is due to forces such as hydrogen bonding, dipolar forces, hydrophilic ("water loving") or hydrophobic ("water hating") interactions, and surface tension, gravity, and other forces involved in making such "self-assembly" happen. Many naturally occurring biological structures like membranes, vesicles, and deoxyribose nucleic acid (DNA) are formed by self-assembly.
Repeating structures with a tailored periodicity are also important in applications of nanotechnology, like photonics and improved catalysts. Understanding and building nanostructures through self-assembly is at the core of creating nanotechnologies.
Nanotubes: Nanotubes, most notably the fullerene-like "chicken-wire" construction of carbon atoms (carbon nanotubes or CNTs), are another important group of nanoscale structures. CNTs are stronger than steel while at the same time very flexible and lightweight. In addition to the remarkable mechanical properties, nanotubes could replace copper as an electrical conductor or replace silicon as a semiconductor. CNTs also transport heat better than any other known material. Together, these characteristics make nanotubes useful for a variety of applications, including super-strong cables, chemical sensors, nano-wires and active components in electronic devices, field emitters for flat-screen televisions, charge storage for batteries, "tips" for scanning probe microscopes, or additives in nanofabricated materials.
What are the potential benefits of nanotechnology?
Nanotechnology offers the promise of new products to fight disease, improve energy efficiency, and clean up toxic chemicals. Examples of the potential environmental benefits of nanotechnology and engineered nanomaterials include:
- Early environmental treatment and remediation
- Stronger and lighter materials; and smaller, more accurate, and more sensitive sensing and monitoring devices
- Cost-effective development and use of renewable energy sources
- Development of processes with reduced material and energy requirements and minimal waste generation
- Early detection and treatment of diseases
- Improved systems to control, prevent, and remediate pollution problems
Are nanomaterials safe?
EPA's Nanotechnology Research Program will provide information to support nanomaterial safety decisions. The key science questions described in the Nanotechnology Research Strategy are intended to help decision makers answer the following questions:
- What nanomaterials in what forms are most likely to result in environmental exposure?
- What particular nanomaterial properties may raise toxicity concerns?
- Are nanomaterials with these properties likely to be present in the environment or biological systems at concentrations of concern, and what does this mean for risk?
- Can we change properties or mitigate exposure if nanomaterials are present in the environment or biological systems?
Providing information to answer these questions will serve the public by enabling decisions that minimize potential adverse environmental impacts, and thereby maximize the net societal benefit from the development and use of manufactured nanomaterials.
How does nanotechnology relate to existing disciplines like chemistry or biology?
Nanotechnology overlaps significantly with many disciplines with chemistry, physics, and materials research. These are the fields that discovered the atom and understood its inner workings, developed the science of combining them in precise structures, and developed tools with which these nanostructures are probed and visualized. Manipulation of atoms and nanostructures is what nanotechnology is all about.
Nanoparticles and other nanostructured materials are often synthesized using chemical methods. However, nanotechnology is fundamentally different from traditional chemistry because it deals with manipulation and physical control at the atomic level of chemicals. Synthesizing a chemical with nanotechnology could actually mean building it atom by atom.
Traditional chemistry in contrast works on a bulk scale. Chemical syntheses typically result in poor yields of desired products with many unwanted by-products. Using nanotechnology to synthesize chemicals could result in greater yield of the desired products and fewer by-products. It could also mean using a nanostructured catalyst in a traditional chemical reaction to improve the rate or yield of products.
For biologists, studying molecular-level structure and function is also nothing new. Applying nanotechnology, however, significantly alters the work of biologists. Traditional biology involves the study of living systems, ranging from bacteria to beetles to humans. All of these organisms rely on nanometer-sized protein machines (molecular motors) to do everything from whipping flagella to flexing muscles. An application of nanotechnology would be isolating one of these molecular motors from a living system and using it to construct a nanoscale device. A nanotechnology derived molecular motor might be fueled by sunlight and produce a rotational force that could pump minute volumes of fluids (e.g. pharmaceuticals) or open and close valves in nanomechanical devices.
Who does nanotechnology?
Scientists and engineers in many different fields of study are involved in nanotechnology research and development. In the cross-cutting area of nanoelectronics, most researchers represent the fields of chemistry and physics. Those involved in nano-biotechnology, however, come from more diverse backgrounds, from optical physics and pathology to chemistry and mechanical engineering. Environmental applications of nanotechnology are also carried out by a diverse group of researchers, including environmental engineers and chemists.
What are the essential items in the nanotechnologist's toolbox?
The scanning tunneling microscope (STM) and atomic force microscope (AFM) are essential items in the nanotechnologists toolbox and are key to the emergence of this new field of science and technology. Nanoscale science essentially began with the groundbreaking invention of the STM, for which Gerd Binnig and Heinrich Rohrer of IBM were awarded the Nobel Prize for Physics in 1986.
Traditional microscopy works by reflecting either light (in the case of optical microscopes) or an electron beam (in the case of electron microscopes) off a surface and onto a lens. AFM and STM use a cantilever (a nanoscale arm) to "read" the electronic properties of a surface directly. Scientists can use these techniques not only to see atoms but also to push and pull them into place.
A significant part of nanotech research also involves the creation of nanoscale patterns using electron-beam lithography. Unlike photolithography, the technique used to make microchips, electron-beam lithography is not constrained by the wavelength of light. Using a beam of electrons from a scanning electron microscope, researchers can etch details on a chip as fine as a few nanometers.
Why is EPA studying nanotechnology?
With the use of nanotechnology in the consumer and industrial sectors expected to increase significantly in the future, nanotechnology offers society the promise of major benefits. The challenge for environmental protection is to ensure that, as nanomaterials are developed and used, unintended consequences of exposures to humans and ecosystems are prevented or minimized. In addition, knowledge is needed on how to sustainably apply nanotechnology to detect, monitor, prevent, control, and clean up pollution.
What is EPA's Nanotechnology Research Program?
EPA's Nanotechnology Research Program in the Office of Research and Development conducts focused research on nanotechnology to address risk assessment and risk management needs to protect public health and the environment from potential harmful effects that may result from production, use or disposal of nanomaterials. EPA participates with other federal organizations to study nanotechnology.
EPA has a unique role among federal agencies to provide the science to determine the potential hazard and risks to nanotechnology and to develop risk management approaches to reduce or minimize any risks identified. The Agency's Office of Research and Development has the following capabilities:
- Expertise to integrate human health and ecological data important to risk assessment and decision support.
- Facilities to test nanomaterials in aquatic and terrestrial ecosystems, as well as to measure and model the fate, transport, transformation, and effects of nanomaterials in environmental media.
- Unique and extensive historical laboratory expertise and capacity to identify approaches to prevent and manage risks from environmental exposures to nanomaterials, including the development and verification of technologies to detect, measure, and remove nanomaterials from environmental media.
- Capability to leverage results from EPA STAR grant research, as well as collaborate with grantees to address the many challenging research issues.
What is EPA studying?
The Nanotechnology Research Program is focusing on four areas that take advantage of EPA's scientific expertise as well as fill scientific gaps not addressed by other federal organizations that are studying various aspects of nanotechnology.
The four research themes are:
- Identifying sources of nanomaterials and how they are transported through the environment to their destination (fate and transport) and how people may be exposure to nanomaterials.
- Understanding human health and ecological effects to assist with conducting risk assessments and development of scientific methods to help with risk assessments
- Developing risk assessment approaches that can be used in decision making to identify and evaluate potential risks of nanomaterials
- Preventing and mitigating risks of nanomaterials in the environment
What are the research goals?
EPA believes that its research should advance two key objectives:
- To develop approaches for identifying and addressing any hazardous properties while maintaining beneficial properties before a nanomaterial enters the environment
- To identify whether nanomaterials present environmental risks once they enter the environment EPA will pursue these objectives by studying the life cycle of nanomaterials from its production, through its use in products, and as it is disposed of or recycled.
How is nanotechnology research planned and implemented?
The Nanotechnology Research Program has a Nanomaterial Research Coordination Team, which is a cross-EPA research planning group. Members are responsible for communicating EPA's highest priority research needs across the organization and for informing the Agency and partners about research activities and products developed by the program.
A Nanotechnology Research Strategy (49pp, 1.6MB, About PDF) provides a roadmap for conducting research to achieve long-term research goals while allowing the flexibility for EPA to address emerging nanotechnology issues that are affecting specific programmatic areas.
How will EPA's nanotechnology research be evaluated?
The Nanotechnology Research Program will be evaluated by the Board of Scientific Counselors (BOSC), an independent review panel of outside experts.
Who does EPA work with on nanotechnology research?
EPA is coordinating and collaborating with other federal agencies and science partners to develop the information, methods, models and tools needed to support decision making about nanotechnology uses and applications.
- EPA is the federal government's coordinating agency for the "Nanomaterials and the Environment" and "Risk Management Methods" areas of the National Nanotechnology Initiative strategy (PDF) (53 pp, 1.3MB About PDF) EPA also co-chairs the interagency Nanotechnology Environmental and Health Implications (NEHI) working group and is leading efforts, such as planning state-of-the-science workshops, to advance implementation of the interagency strategy.
- The research program is issuing joint grant requests for applications (RFA) to conduct nanotechnology research with other federal agencies, including the National Science Foundation (NSF), the National Institute for Environmental Health Sciences (NIEHS), and the National Institute for Occupational Safety and Health (NIOSH).
- EPA scientists are coordinating and collaborating with colleagues in other agencies, such as with the National Toxicology Program and the National Institutes of Occupational Safety and Health to study nanomaterials such as carbon nanotubes.
- New national Centers for the Environmental Implications of Nanomaterial (CEINT) are being co-sponsored with the National Science Foundation to conduct fundamental research and education on the implications of nanotechnology for the environment and living systems at all scales. The CEINTs will address interactions of naturally derived, incidental and manufactured nanomaterials with the living world.
- EPA is testing a number of nanomaterials as co-sponsors of the Organization for Economic and Cooperation and Development (OECD) Testing Program . EPA researchers will divide testing responsibilities and share test materials with the co-sponsoring organizations.
- EPA's Nanomaterial Stewardship Program (NMSP) will provide material-specific and general information that will be useful to advancing EPA's research program.