Sunday, October 6, 2019

Out of Sight

How tiny is tiny? Or how thin is thin? A pharaoh ant or a strand of hair, perhaps? Sounds like a specious response to a silly quiz. In fact, human cognition allows us to perceive nature at, and beyond, eye-level resolution while innate curiosity leads us to explore our environment in all its complexity. Unprompted, we are constantly seeking to make sense of our place in a universe containing objects both great and small.

In Jonathan Swift’s Gulliver’s Travels, we are treated to a satire featuring several voyages undertaken by Lemuel Gulliver. On his first trip, he was shipwrecked and held prisoner on the island of Lilliput, inhabited by a race of tiny, half-foot tall people. With more than a ten-fold height advantage, Gulliver had to be extremely nimble around the Lilliputians to avoid harming them. Bizarrely, they possessed a sense of self-importance that belied their small size, starkly demonstrated when the Lilliputians’ army corps paraded around and between Gulliver’s legs. On returning home, Gulliver next visited the Brobingnagians, a race of giants, on average about twelve times taller than Gulliver. While his new hosts were more hospitable than the Lilliputians, he never felt comfortable or safe amongst them, beside the fact that the Brobingnagians treated him like an exhibit in a freak show.

The political undertones in Gulliver’s Travels are unmistakable, but do not subsume the simple inference that size is relative. Outside a customary frame of reference, thinkers often resort to thought experiments to speculate about worlds unseen, while well-kitted researchers have been able to probe natural phenomena more objectively. In due course, two amazing instruments - the periscope and microscope - magnified and forever changed our perception of the physical world.

While the study of the universe is largely the domain of astronomers and cosmologists who deploy relatively expensive instrumentation, the study of small organisms and objects is comparatively within reach. Dating back to the early 17th century, the invention of the compound microscope (which combines an objective lens with a viewing eyepiece) has evolved to modern scanning probe microscopes with unprecedented capabilities.

Welcome to the world of nanoscience and nanotechnology - the study and manipulation of objects at the atomic and sub-molecular scale, in the order of a nanometre (10-9 metre). So, in relative terms, how wide is a nanometre? A spherical object with a diameter of one nanometre is comparable in size to a football, as a football is to planet Earth! With the invention of the scanning tunnelling microscope almost four decades ago, it became possible to manipulate sub-molecular particles at that level of resolution for the fabrication of macroscale products. Since the early years, nanotechnology has found applications in diverse industries, including energy, manufacturing, agriculture, pharmaceuticals, cosmetics, sports, transportation, electronics, and healthcare.

Essentially, there are two methodologies employed in nanotechnology. First, there is the bottom-up approach, whereby nanomaterials and nanodevices are assembled from the ground up at the molecular level. By contrast, the top-down mode of microfabrication begins on a larger scale without molecular control. So far, possibly the greatest advances have emerged in the commercial nanoelectronic semiconductor sector, which underpins the high-technology industry.

To be clear, no one is suggesting that people should stop hankering after smartphone upgrades. However, due to an intuitive sense of self-preservation, healthcare probably occupies a special perch in our consciousness. As an emerging discipline, nanomedicine explores the impact of nanotechnology on medical interventions such as diagnostics, drug delivery, blood purification, tissue engineering, as well as the fabrication of bio-sensors and bio-nanodevices. 

To all those who look forward to the day when “going under the knife” will be severely curtailed or obsolete, nanomedicine would be a godsend. This new dawn could presumably empower medical personnel to, in situ, repair damaged tissue, remove toxins and pathogens from blood, deliver drug nanoparticles to targeted sites, and use biological nanomachines to weld arteries. As nanomedicine matures and becomes more widely accessible, minimally invasive surgery will become a game-changing reality.

If you are dismayed by the idea of autonomous nanomachines performing surgeries, the good news is that microsurgery would most likely remain under the control of human surgeons. When it comes to matters of life and death, most people would rather leave decision-making and crucial judgments in the hands of trained doctors instead of artificial intelligence-enabled (AI) robots. Out of sight medical procedures should not necessarily translate into the total abdication of human responsibility.

Nanotechnology, like space exploration, is opening up a new frontier that is pointing the way to a brave new world where archetypes of Lilliputians and Brobingnagians will continue to challenge our imagination.


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