Aug 23, 2022
(Nanowerk Spotlight) Throughout human history, technological progress has been inseparably intertwined with advances in military weaponry. Through the ages we can see how new inventions revolutionized both the living standards of society and the advancement of warfare technology. The Stone Age, Bronze Age and Iron Age led to a progression of wooden, stone and metal weapons from arrows and bows to spears, axes, swords, chariots, and heavy siege weapons.
With the invention of gunpowder in ninth-century China, chemical explosives entered the stage. While initially intended for use in pyrotechnics, it saw widespread use throughout the world in the development of small firearms and artillery guns.
In the early 20th century, World War I became a flash point for the development of various advanced warfare technologies not only for ground wars (long and short range guns, tanks, chemical weapons) but also for emerging air forces (aircraft, helicopters) and navies (battle ships, submarines). The full-scale demonstration of these technologies appeared during World War II in addition to the development (and use) of the first nuclear weapons.
The second half of the 20th century witnessed the moon race between the large superpowers USSR and USA, which led to the development of ever more powerful missiles. In addition, great emphasis was given to the development of ever more lethal weapons of mass destruction in the form of NBC (nuclear, biological, chemical) technologies despite a range of international treaties against the development and use of such weapons.
This period also saw an increased emphasis on the development of protective technologies such as armour, camouflage, and stealth.
The rise of new technologies
The rapid emergence and confluence of nanotechnologies, biotechnologies and information technologies in the past two decades is having a huge impact on the development of military technologies. Some examples:
Nanotechnology-enabled new structural materials: High strength, light weight, corrosion and heat resistant structural materials (metals, alloys, ceramics, polymers, composites).
Thin-films made of nanocarbons that can be deposited onto surfaces for electrically active coatings.
Nanocomposites and engineered nanoparticles for high-energy munitions.
Nanometals and energy-absorbing nanomaterials for for armaments.
Self Decontaminating Surfaces exploiting surface structures of nanomaterials.
'Smart' equipment including protective clothing, armours and ammunition; improved low observability (camouflage); sensing and mitigation of threats from landmines and chemical, biological, radiological and nuclear (CBRN) warfare agents.
Biotechnology-enabled sensor technology, biocomputing, bioengineered materials, biofuels, etc. Also military performance enhancement or wound stabilization and treatment. The darker side of application of biotechnology include the genetic modification of pathogenic materials including virus to cause bioweapons of mass extinction.
Information technology (involving hardware, algorithms, and software) already has brought revolutionary changes in several military domains such as surveillance, communication, data transmission and cryptography. Advanced C4ISR capabilities – standing for Command, Control, Communications, Computers (C4) Intelligence, Surveillance and Reconnaissance (ISR) – provide an advantage through situational awareness, knowledge of the adversary and environment, and shortening the time between sensing and response.
Integrating various components of these technologies into an Internet of Military Things (IoMT) for combat operations, complete with artificial intelligence algorithms, advanced sensor technologies, and autonomous weaponry such as drones, will determine the shape and scope of futuristic battlefield scenario [1].
Future warfare technologies that will be greatly influenced by nanotechnologies include stealth, unmanned aerial vehicles (UAVs), precision-guided weapons, as well as miniaturized firearms, sensors, and energy harvesting technologies. Below we address several aspects that will be greatly impacted by future military technologies:
Smart Soldiers
Since prehistoric times, soldiers have been indispensable in fighting wars for any army – but their technology has changed immensely.
For instance, the price of providing soldiers with modern communications and surveillance equipment comes with a heavy price – literally. It has been reported that the average weight of batteries carried by US Army combat personnel in Afghanistan could amount to 4.5kg – with some soldiers carrying 11-13kg depending on their battlefield role. Considering that a modern infantry soldier will carry equipment weighing 30-50kg, the need to reduce this burden has becomes a pressing issue for military R&D.
In this context, very intensive efforts are being made by researchers to develop nanotechnology-driven textiles embedded with nanosensor elements for CBRN threats, insulated and water proof fabrics, together with light weight bullet and splinter protection. Furthermore, textiles embedded with photovoltaic, thermoelectric, or piezoelectric nanomaterials for energy harvesting and storage will reduce the dependence on conventional batteries. Integrating all these technologies will result in a dynamic, lightweight and comfortable-to-wear battle suit.
Nanomaterial-enabled light-weight body armour
Replacing the currently in use heavy-weight body armour (14-15 kg) is a strong R&D focus. Materials that meet the criterion for an armour should not only prevent the penetration of a bullet but should also have elastic energy for bouncing off or deflecting the bullet. Instead of the dense ceramics and steel that are currently used, various nanomaterials such as magnetic and nonmagnetic ceramics as well as carbon based systems have emerged as ultra light weight materials.
Among them, carbon nanomaterials including carbon nanotubes (CNTs) and graphene are of great interest for the fabrication of ultra-light body armours because of their attributes:
Ultra-light weight
Formation of high strength composites particularly in polymer and ceramic matrices
Blends of CNTs in polymer fibers such as Kevlar, Zylon, and polyethylene, give rise to composites showing low density, high mechanical strength, thermal resistance to degradation and absorption to high-energy appears to be right choice for light weight body armours. For example, the simulation results show that a CNT may stop a bullet without through penetration, as shown in Fig 1a. This is attributed to the length of CNT, showing a linear relationship with absorption energy (Fig 1b), absorbing the kinetic energy.
A minimum of six layers of woven nanotube yarn material at a thickness of 600 µm should be sufficient to absorb 320 J of the muzzle energy in the impact area
The mechanical properties of graphene, such as Young's modulus, which measures the resistance to deformation, are very large: >1 TPa even better than CNT and diamond. As shown in Fig 1c, theoretically graphene sheet with honeycomb 2D structure may deflect a bullet like a volleyball on a net
Moreover, the specific penetration energy, that is, resistance to the kinetic energy penetration, for multilayer graphene is ∼10 times more than that for macroscopic steel sheets at a bullet speed of 600 ms−1 thereby making it a much more stronger candidate with much lighter in weight than any other existing material.
In view of the practical difficulty of fabricating stand-alone armour for a soldier, composites of graphene and CNT put together in a polymer matrix e.g., polythene is demonstrated to provide a stronger bullet proof armour of 
