Nanotechnology paves way for new weapons

Jane's Chem-Bio Web, 27 July 2005

Advances made in the field of nanotechnology could be applied in the development of a new generation of chemical and biological weapons, writes Andy Oppenheimer.

Current and future developments in nanotechnology—science and engineering on the scale of nanometres or billionths of a metre—may pave the way for new types of weapons. The new technology will have a profound impact on new materials, electronic devices, chemical, biological and mechanical systems and provides the potential for future weapons development. Previous articles on Janes Chem-Bio Web discussed the potential of nanotechnology being used for a fourth generation of nuclear weapons. This article deals with its potential to enable future production of novel chemical and biological weapons (CBW).

Dual-use medical advances

Nanotechnology has great potential in the fields of biotechnology and medicine. Bio-nanotechnology is concerned with molecular-scale properties and production of materials and devices including tissue and cellular engineering scaffolds, molecular motors and biomolecules for sensors and drug delivery. While bio-nanotechnological products are seen as around 10 years off, medical application is promising, with intense research being conducted in disease diagnosis, drug delivery and molecular imaging. Medical-related products containing nanoparticles are currently on the market in the US. DNA-based geometrical structures (including artificial crystals) and functioning DNA-based nanomachines are currently being fabricated.

Nanotechnology will provide possibilities for more efficient storage, dispersal and transport of chemical and biological agents into the body and cells of humans, animals or plants and could make delivery of existing drugs more effective. Current drug therapies often operate like a sledgehammer cracking a nut rather than selectively targeting a specific organ system, often with adverse effects. Pharmaceutical companies in several countries are working on nanoparticles that help the body absorb drugs. This will solve the current problem where up to half of all drugs in development effectively work against their targets but are rejected because the body cannot absorb them due to the drugs poor solubility.

As all biochemical activities and the interactions of protein surfaces take place on a nanometer scale within cells, so-called nanorobots could be built to enter cells. The delivery vehicle could be a functionalised nanoparticle capable of targeting specific diseased cells, which contain both therapeutic agents that are released into the cell and an on-board sensor that regulates the release. While the combined targeting and controlled release have yet to be achieved, trials and eventual approval are probably not far off.

As with many technologies, the medical applications may be adapted for offensive purposes. Manipulation of biological and chemical agents using nanotechnologies could result in entirely new threats that might be harder to detect and counter than existing CBW. New agents may remove previous operational difficulties of biological warfare, such as effective delivery of the agent. The large surface area of nanoparticles, relative to their overall size, increases their toxicity when inhaled. Advanced capabilities may include the use of genetic markers to target specific organs in the body, or an ethnic group, or even a specific individual. Chemical compounds could be created to target specific physiological functions and could be based on complex multi-layered stealth designs to avoid detection.

A more advanced weapons application would be to adapt nanocapsules, currently under development, that deliver a drug when activated by temperature. They may be used to target tumours and destroy them once activated by microwaves. The same nanocapsules could contaminate target subjects when selectively activated. This would depend on administering drugs to willing recipients rather than being used in military situations to target troops or civilians over a large area. Compounds that were previously unsuitable for biological weapons could be enhanced to penetrate organs more effectively.

Biological materials have remarkable advantages over inorganic materials in terms of the diversity of self-assembled structures that they can produce. It has been suggested that hybrid nanomachines, composed of biological material with inorganic components, could pose a threat if they are able to replicate, although they are currently not able to do so.

Chemical weapons

Chemicals in nanoparticulate form currently account for only a tiny fraction of the world total (around 0.01 per cent) currently produced, although the market for nanoparticles is expected to increase during the next decade.

While the production of new chemical weapons is banned by the majority of nations, future techniques, depending on cost and ease of production, may be adopted by remaining countries with chemical weapons programmes and terrorist groups. A nano-enhanced chemical such as cyanide could be synthesised in far smaller amounts. The design of new agents that attack specific body organs such as the central nervous system would enable far smaller amounts of the chemical to be made without detection and would require only small, low-level facilities.

Other nanotechnology-based weapons might emerge from otherwise benign fields such as law enforcement in the creation of non-lethal weapons for riot control and other policing operations. Some of these are currently permitted under the Chemical Weapons Convention. New delivery mechanisms to make incapacitating substances target more selectively could be adapted to more lethal uses.

CBW defence

The technology, however, also opens up the possibility of creating more effective sensors to detect and prevent chemical and biological attacks, as well as more effective means of containing chemical or biological releases. The ideal sensor is minimally invasive and therefore as small as possible. Nanotechnologies are therefore expected to enable the production of smaller, cheaper sensors with increasing selectivity, as they will enable the sensing element to be specific and accurate. For chemical detection, this may require detection at the level of a single molecule.

Pervasive nanosensors will contribute to national defence capability through early detection of chemical or biological releases and increased surveillance capability. The US Department of Defense (DOD) is using nanotechnology to develop improved CBW sensing, such as single-molecule detectors to monitor air or drinking water and to detect the presence of toxins in the environment.

Issues arising

CBW created through nanotechnology could evade international arms control and verification regimes, which ban existing, not future, weapons. Nanotechnological applications have the potential to undermine these regimes by allowing the development of a new generation of potentially undetectable weapons. United Nations inspectors would have to know how to identify existing and emerging nanotechnologies as they apply to CBW.

Refinements of both existing and new biological weapons systems through applications of nanotechnologies could lead to a new arms race. But like existing biological weapons, such new weapons could instead be rejected by many militaries as they may easily backfire and infect or overwhelm friendly forces or areas other than targets.

Control of weapons is always dependent on the state of scientific progress. Scientists and engineers recognise that nanotechnology has fundamental limits, but the position they take regarding their contribution to weapons research and development will also be a prime factor in whether such weapons will be produced. Also, accidents and abuses of a technology could be within the reach of individuals or small groups, who will be able to make weapons with small-scale facilities. As is the case with much of the available information on non-conventional weapons, much of the basic knowledge and technology needed to achieve military capabilities using nanotechnological applications is dual-use. Because they will be produced within the civil sector, methods of manufacture will be potentially available to many, including terrorists.

Technology is often ahead of social and political responses to it, so that the means to develop weapons arrives long before any public debate can take place. In the case of nanotechnology and CBW—and nuclear weapons—the debate may occur ahead of technological development, partly because civilian research and development is underway. While many of the weapons applications lie in the future, there are calls for scientists and others involved in nanotechnology to acknowledge their responsibility to prevent harmful applications of nanotechnology and, as the most technically informed, attempt to influence the establishment of new regulations.

While military applications are not currently at the forefront of nanotechnological development, secrecy enforced as a result of military funding will hinder the open peer review of findings. This, in turn, may lead to public concerns and suspicions about civilian developments, as has been the case with nuclear power.