The Big World of Small TechEmmet Feerick peers into the tiny, yet growing, world of nanotechnology.[br]AS far as prefixes go, nano is right up there with quantum and hyper in terms of its science-fiction appeal. Nothing captures the imagination quite like the vagueness of these terms when coupled with the word ‘technology’. Unlike many such couplings, however, nanotechnology can take credit for being both a godsend to the science fiction writer, and an enormous and rapidly-growing area of science and engineering.The word itself simply refers to the branch of technology that deals with dimensions and tolerances of less than 100 billionths of a metre. A nanometre – the unit of measurement in this space, is one billionth of a metre. To put this scale into perspective, a human hair is 75,000 nanometres across. This is the realm of the atom and the molecule. Where is the room for robots and gadgets here?As it turns out, some are here and more are coming. It would however be a shame to gloss over the astonishing progress already made in the field since its beginnings in the 1980s. The dream of seeing individual atoms was finally realised in 1981 with the invention of the scanning tunnelling microscope. Rather than using light rays, as with a traditional microscope, this microscope (which was itself quite macro, taking up a few desks worth of space) used variations in the electrical current induced in a tip moving just over the surface being examined to determine its structure. By 1989, this microscope had been used by researchers at IBM to manipulate individual atoms. In fact, they were able to move around 35 xenon atoms to spell out the initials ‘IBM’. This achievement marked the start of the modern era of nanotechnology.
"Nanotechnology has the potential to give us computers the size of molecules”After relatively slow progress in the 1990s, scientific and commercial interest in nanotechnology exploded in the mid-2000s. In 2005, the US invested over a billion dollars into the area, which was more than twice what they put into the sequencing of the human genome project at its height.And what did they have to show for it? As of 2015, there were over 1600 manufacturer-identified nanotech products publicly available. Most of these are of the passive nanomaterial variety; the adding of titanium dioxide to sunscreen to increase its UV-blocking effectiveness, silver nanoparticles in bandages to heal wounds faster, and hydrophobic coatings for raincoats and car windscreens, to give a few examples.You may also have noticed a sign inside your fridge or washing machine which mentions that it uses silver nanoparticles for their antibacterial properties. This technology was introduced by Samsung in 2003.All very well and good, but where does nanotechnology truly live up to its futuristic name? Where is the science fiction stuff? Right now, the closest we can get to science fiction is in the world of medicine. At the nanoscale, researchers have successfully been able to fold DNA into scaffolds which hold other molecules in place – a process known as “DNA origami.” This technology finds many applications in drug delivery, although most of these concepts are still in the testing phase.
“Especially important may be the use of nanoparticles against antibiotic-resistant superbugs.”Perhaps even more impressive is the use of DNA origami to create robots which carry out logic functions to achieve targeted drug delivery in cockroaches. These are not robots in the common-usage sense; metallic machines with arms and actuators. Rather, they are DNA molecules cleverly-folded so as to create logic gates (AND, OR, NOT, etc.), which allow them to function as mini-computers. These allow the robot to carry out functions such as the holding or release of certain molecules.These robots have computational limits imposed upon them by their size and substrate, however, yet current estimates suggest that their computational power can be scaled up to that of a Commodore 64 computer – the wildly successful home computer released in 1982. This is to say that nanotechnology has the potential to give us computers the size of molecules.This and other nanotech applications are set to have enormous implications for medicine if the technology becomes sufficiently advanced, ranging from cellular repair and surgical tool cleaning, to new cancer treatments. Especially important may be the use of nanoparticles against antibiotic-resistant superbugs, due to the declining effectiveness as antibiotics in treating infections.The future looks bright for nanotechnology - the ever increasing fidelity of 3D printers has led to speculation that this technology combined with nanotech will bring about the second industrial revolution. For now, though, it seems that funding and research into the realm of the very small will continue to bring considerable improvements to life at large