Nanobots

by Imogen Holmes, local college student. Originally published in issue eight of Resonance.

Xenon atomsPicture a robot, and the image that might come to mind is one of a metallic machine, often a crude representation of a human, designed to perform simple tasks such as cleaning or cooking. An image less likely to come to mind is that of a nanoparticle-sized machine, moving within your bloodstream.

Welcome to the world of ‘nanobots’, or nanotechnology as most scientists prefer to call it. Thee idea of nanobots first entered the scene in 1959, when Richard Feynman gave a lecture titled "There’s plenty of room at the bottom" introducing the idea that nanotechnology could one day be used within the body as part of biological and medicinal systems. However, nanotechnology faced a major limitation; electron microscopes of that era were not powerful enough to resolve individual atoms.

Two major breakthroughs allowed progression in nanotechnology: the scanning tunnelling microscope was developed in 1981 by Heinrich Rohrer and Gerd Binnig, and Binnig then went on to develop the atomic force microscope in 1986. These techniques allowed materials to be manipulated at the nanoscale, and have unlocked the great potential of nanochemistry, with some of the most exciting current research being nanobots.

Devices are being developed with features that a medical nanobot would require. A nanobot with a metal helix type structure has been developed which can attach to a sperm cell, aiding its transport to an egg cell by use of a magnetic field – although they have been unable to use the nanobot to actually fertilise the egg. However, with further research this may be of huge benefit to couples struggling to conceive, as a low sperm count is the main problem in 20% of infertility cases.

Yarn motorAlternatively, the power of a sperm cells agellum (or that of any other mobile cell) could be harnessed by a biohybrid nanobot, which could bind and deliver drugs to specific cells, removing the need for motors.  This would be particularly useful when treating cancer, as an alternative to treatments such as chemotherapy, which harm all fast dividing cells – not just cancer cells.

In 2009, nanobots with tails that mimic agella were developed, and in 2017, a faster nanobot was developed that mimics front crawl movements. It is able to "swim" through viscous liquids (such as semen), and is being tested on other bodily uids such as blood plasma. Perhaps in the future these nanobots may also be used to deliver drugs to cells in our bodies.

Most trials have taken place in vitro, as many use toxic fuels such as hydrogen peroxide, which are toxic to humans. Hence, nanobots controlled by a magnetic  field may prove to be better alternatives. Another problem to solve before use in the human body, is removal of nanobots when treatment has nished. Possibilities include using biodegradable materials, or guiding the nanobots out of the body through the digestive system.

There are some remaing issues: manufacturing would not be cheap, as materials must be highly pure with few defects. Would the benefits of this treatment justify such a high price? Could nanobots become autonomous, or find some way of replicating inside the body?

However, fastforward a few decades and having nanobots injections may be a normal part of any hospital trip, revolutionising fertility and cancer treatments, and even other areas of medical science. Who knows?

Read more from Resonance

References:

  1. IBM (atoms), Wikipedia
  2. Tiny twisting muscles developed for propelling nanobots, New Atlas