Nanotechnology

The word nanotechnology was coined by American engineer Eric Dexler in his book Engines of Creation (1986) to mean the production of virus-sized structures, devices and systems through techniques of microtechnology (nanoelectronics among others) and molecular biology (nanotagging among others). It has been described, with a touch of artistic license, as atomic-scale sculpting, if manipulation of nanomaterials is taken into account. Although invisible, atoms and particle zoos shape our world, and this explains why we want to visualize them as precisely as possible, even at the cost of entangling imaging with imagining. Today, thanks to nuclear magnetic resonance and cryoelectron microscopy, we can peer into molecular landscapes dramatically different from those depicted in the old biology textbooks.

Dexter was the first to glimpse the likelihood of nanoscale machines programmed to create new units identical to themselves, assemblers capable of constructing more assemblers and quickly multiplying. Fast and out-of-control, the manufacturing rate would become exponential, ensuing an unrelenting torrent of assemblers. Eventually, they would strip the Earth of all organic matter, covering the planet with a gray goo mantle, an event scientifically named ecophagy. That is a seriously weird fantasy vision, absolutely off the table. Today, what most closely resembles self-replicating machines is a synthetic molecular assembler that produces polymers ―and not as fast as computer viruses and quines.

Quantum Polka Dots

Nanocrystals are tiny particles ranging between 2 and 10 nonometers and offer a variety of applications. As they are semiconductors, that is, they can transport electrons, there are obvious employments of electronic nature, but for having the capacity to emit light over a wide range of wavelengths.

The overriding drawback is that the dots are made of toxic heavy metal elements. Fortunately, new studies have found that carbon dots can assume the function. But not all of them. Scientists are now carrying out selection procedures to purify carbon dot populations, separating the perfect emitters from the bad ones, with the hope of synthesizing them at some time.

Clean with Caution

Scientists have introduced nitrogen, carbon or metals into the titanium structure, creating a nanoparticle showing unique optical properties, the titanium dioxide. Such exotic element show photocatalysis properties, attributed to its handling of natural or artificial light to stimulate chemical reactions. This can be translated into nanoremediation techniques that transform, through luminous energy, hazardous air pollutants into harmless compounds, as well as water disinfection processes.

This nanoparticle 'blinks' and scientists do not know exactly what happens, but they assume it has to do with electrons staying trapped within titanium dioxide struct. Nature is mysterious and that is why it is necessary to recognize its 'deep uncertainty', applying the precautionary principle to analyze the potential risks of nanotechnologies. It seems to be unwise to embrace the opposite ―the proactionary principle― under this heading.

What Lies Ahead

Self-assembled Nanoparticles

In nature, the old dream of self-replicating assemblers is a reality since remote times, and one might take cues from prions, protein aggregates that are able to self-propagate abnormally. But, in the world of nanomanufacturing, building an assembler is extremely difficult. Against all odds, new nanofabrication methods are emerging every year and self-assembled nanoparticles-based materials are making a start on a no longer impossible future.

The results of a research that brings DNA origami technique to a new level has recently been released. Columbia engineering researchers were able to 'cast' 3D silica structures that can be pulled from nanoparticles sculpted out of DNA. The technique of directing the self-assembly of nanoparticle-based materials into desired nanostructures has already been mastered, but only in 2D and liquid state architectures. This achievement might enable the formatting of close-knit electronic nanoobjects, as lattice-shaped transistors, breaching Moore's law dead-end, especially in relation to miniaturization.

Self-assembling Replicators

Whilst the majority of scientists think it’s improbable ―if not to say impossible― to eradicate SARS-CoV-2 in no time, they at least have been successful in the rapid delivery of mRNA vaccines. But given the severity of the crisis, much more is needed. It is expected that they could leverage nanotechnology in developing antiviral agents with new platforms. This makes it possible to produce self-assembling virus-like particles (VLPs), devoid of genetic material, an ersatz of traditional antigens that induce immune responses, with the advantage of being non-infectious.

If all goes well, VLP-factories shall form part of a larger project to improve human condition in the near future, something already put forward by NBIC, or the convergence of nanotechnology, biotechnology, information technology, and cognitive science.