# Do “nano bots” (that can fit inside the human body) actually exist?

I was wondering, do we have real nano bots, like the ones in the movies?

I think we have bots which can move through the blood vessels, am I right?

• What movies? Might help clarify what characteristics you are looking for. – Josh Vander Hook Jan 13 '13 at 22:34
• Like "Transformers" and "Aeon Flux"... – ATOzTOA Jan 14 '13 at 3:43
• @JoshVanderHook A movie that comes to my mind is Fantastic Voyage - en.wikipedia.org/wiki/Fantastic_Voyage - really scifi. – ott-- Feb 18 '16 at 15:13

Yes! Yes we do have robots which can swim through the bloodstream!

rics did a good job of summarizing the difficulties in producing a completely autonomous nano robot. Something like a Mars rover, with more autonomy, but tiny. This is not the only type of robot. While this is definitely beyond the capabilities of our current-day researchers / engineers, there is another thread in this domain that is worth mentioning: nano manipulators.

Traditionally, robots have been automated manipulators. In the case of robotic manipulators, most of the processing and localization challenges are offloaded, and the robot just carries out the task of delivering part A to location B.

This closely matches the job description of a nano robot: deliver drug A to organ B, or take sample A, etc. In this case, a very small magnetic manipulator can be inserted into the body and moved, turned, etc, by use of magnetic fields from outside the body. So the robot ends up being a small piece of innocuous metal.

(source: ethz.ch)

Think of it as the "hand." The magnetic fields are the "arms," an MRI is the "eyes," and a computer somewhere is the "brain." Its not fully embedded, but it is technically a nano-scale robotic manipulator.

If you are interested in this (who wouldn't be?) Check out the following. There are plenty of awesome videos ahead:

• The key guy in this field is Brad Nelson. He gave a keynote talk at ICRA 2012, in Saint Paul, MN. It is available freely here. Have a look.

• More information (including the above reference paper), can be found on his webpage, http://www.iris.ethz.ch/msrl/research/current/index.php

• One of the coolest takeaways from the talk was his work on "swimmer" robots. More info (and videos!) here: http://www.iris.ethz.ch/msrl/research/current/helical_swimmers/

• There are two types of manipulators he is researching, but both are inserted, tracked using MRI, moved / manipulated using magnetic fields, and then removed via a simple needle.

• The two types are based on size. A larger manipulator is easier to move using magnets, but a smaller one can be more precise.

My impression after the keynote talk was this technology is quickly approaching human trials. They have tested in cow eyes and other biological organs. I'm interested to see what they produce this year.

• So we MAY have robots which can swim through the human bloodstream this year? – rics Jan 14 '13 at 7:50
• @josh, wait, doesn't MRI blow you up if you have metal inside you? – Shahbaz Jan 14 '13 at 11:37
• @Shabaz, I have no idea about MRI, etc. Its outside my domain, but the link above clearly states that they are tracking their nano robots using MRI. – Josh Vander Hook Jan 14 '13 at 18:36
• "So the robot ends up being a small piece of innocuous metal." This is not quite true. The robot is the piece of metal inside the body, plus all the apparatus needed to locate and manipulate that piece of metal -- which is located outside the body. – Ian Sep 6 '13 at 16:38
• The link to the swimmer bot image has died... :-( – Greenonline Feb 17 '16 at 7:42

Movement of Artificial Bacterial Flagella in Heterogeneous Viscous Environments at the Microscale is a recent article from ETH Zürich that discusses the movement possibilities of an artificial bacteria in the blood stream or in the eye. Swim tests were performed in different methyl cellulose concentrations.

I do not think so that such methods can be used in human body in the near future because of the existing technological constraints.

It is still not clear how to

• create such small machines from non-allergic material
• with effective motors
• and small battery storing enough energy for the duration of the job
• that can move inside the body without making any harm e.g. blocking the blood stream
• and that can deliberately move to the planned location
• recognize the destination
• and perform its job there
• and finally that could leave the body after the job is done,
• all reliable and stoppable if necessary, even with the possibility to track the progress.

† by Kathrin E. Peyer, Famin Qiu, Li Zhang, and Bradley J. Nelson (978-1-4673-1735-1/12/S31.00 ©2012 IEEE)

• could you expand a bit more on your thought? What constraints are you talking about? Is it the manufacturing technology of robots that size? Is it the distrust of those robots used in a human body? – Shahbaz Jan 13 '13 at 13:29
• I have added some thoughts about the sub-problems that needs to be solved. I think that there are some progress in some of them but neither is ready to be used and as a complex they are far from applicable. – rics Jan 13 '13 at 15:39
• haha, so basically nothing is clear! – Shahbaz Jan 13 '13 at 18:46
• You assume a very narrow definition of robot. – Josh Vander Hook Jan 13 '13 at 22:34

The branch of science that most closely resembles "nano bots" is Capsule Endoscopy.

The first generation of these were just "edible" video cameras with cameras inside, which passively recorded one's digestive tract. The most recent round of development is focusing on making them smaller and more maneuverable.

They are still not small enough to pass through blood vessels (at least, not safely).

• I wouldn't call that neiter a nano nor a micro bot. It could be a mini bot. – ott-- Feb 17 '16 at 15:27
• If you can find a picture of an existing self-contained micro- or nano-bot, it would be a welcome answer to the the original question. – Ian Feb 17 '16 at 15:36