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

Question

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?

Answer 1

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.

Answer 2

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)}

Answer 3

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).