Nanobot moving erythrocyte red blood cell by motor

Nanobots: fact or fantasy

Emerging technologies can generate fear of the unknown among the public

Nanobots were the vision of researcher Eric Drexler. He envisaged tiny robots (hence the term ‘nanobots’) that could make nanomaterials, atom by atom. The nanobots would replicate themselves by taking raw materials, plucking out the atoms they needed one by one, and then assembling a new copy of themselves.

Are they really dangerous?

He thought so. In his book Engines of Creation (1986), Drexler introduced nanotechnology to the public. He suggested that if a few nanobots were to multiply out of control, they could form a swarm of tiny, precisely engineered yet lethal machines that pulled apart every living thing in their path, atom by atom. He imagined that this rampaging swarm might look like ‘grey goo’. According to one estimate, it would take replicating nanobots just three or four hours to transform all living things on Earth into grey goo. In April 2003, the grey goo scenario apparently prompted Prince Charles to enter the nano-debate, and he called a meeting of leading scientists to discuss nanotechnology.

A closer look

Drexler himself has disowned the grey goo scenario, and Prince Charles has acknowledged it’s not an issue. Furthermore, the idea of little submarines propelling themselves through our bloodstream remains beyond the realm of possibility for today’s technology. However, scientists have recently generated nanobots for use in cockroaches (but don’t jump to conclusions, Charles – they’re being used for good). These DNA nanobots, known as ‘origami robots’ because they fold and unfold DNA strands, are used to deliver drugs. In the future, nanobots may be able to deliver drugs to specific regions of the body, but the reality of this remains a long way off.

Many nano-engineers argue that we should be looking to chemistry and biology for inspiration and taking advantage of Brownian motion, the ‘stickiness’ of molecules and molecular recognition (‘lock and key’ interactions) to build things. Other futuristic prophecies distinguish ‘hard’ nanotechnologies – nanofactories, in which products are built by mechanical processes – and ‘soft’ nanotechnologies, which are based on biological systems.

Soft nanotechnologies merge into biotechnology. They can be seen in projects that combine biological and physical systems, and those that are attempting to create ‘minimal viable cells’, building up simple cells from scratch. As biological systems are known for their powers of self-replication, this has led to fears that the ‘grey goo’ may, in fact, be a ‘green goo’.

Lead image:

Spooky Pooka/Wellcome Images CC BY NC ND

About this resource

This resource was first published in ‘Nanoscience’ in June 2005 and reviewed and updated in August 2014.

Biotechnology and engineering
Education levels:
16–19, Continuing professional development