yigitjohn48 t1_j6nhv97 wrote on January 31, 2023 at 4:14 PM

Hi hocam! My question is how microrobots behave after colonized? (idk right term) Do the bacteria colony behave different than u programmed for? I mean is it emergent or it is behaving similar to computer program, it behaves exactly what you programmed to? Congrats hocam!

intengineering t1_j6oadaj wrote on January 31, 2023 at 7:09 PM

Thank you for your questions. Here in our study, what happens is that we attach nano-sized magnetic particles to bacteria, and therefore, we are able to control those bacteria using external magnetic fields. You can imagine a single bacterium turning into a tiny magnet that can be navigated using a larger magnet, or electromagnetic setup. As for the colonies, with our optimized method, we were able to generate millions of these bacteria (we call them bacterial biohybrids), carrying the magnetic nanoparticles, meaning that we were able to control the swarms of bacterial biohybrids using external magnetic stimuli. Magnetic control mechanisms are quite robust since magnetic fields are safe to use in clinics and it allows for precise control over tiny swimmers. We can technically “steer” them using our electromagnetic coils, they go right when you press right, and go up when you press up on the control panel!

Hope this answers your questions!
All the best,

/birgül

lawless_c t1_j6obb8z wrote on January 31, 2023 at 7:14 PM

Is this making them swim i directions you choose or is it more like dragging them about?

Does the magnetic tool(s) that control them have to be super close, like contact with the body?

intengineering t1_j6oeuco wrote on January 31, 2023 at 7:36 PM

It is not dragging but rather aligning them. So what happens is that the nanoparticles on bacteria align with the applied magnetic field. Therefore, bacteria follow that path. We could also create so-called "magnetic gradients", which would cause dragging or pulling. But we want to use their own motility rather than pulling them.

As for the second question: No, they don't. We use electromagnetic coils (see: https://www.sciencedirect.com/topics/engineering/electromagnetic-coil) that generate enough magnetic field in the center of the setup to steer the microswimmers. These setups are designed for microscopic use, i.e., we attach them to a microscope to simultaneously visualize the motion of bacteria under magnetic fields. Of course, you would need much larger setups for use in humans in the future, but even in that case, it wouldn't be in contact with the body.

Thanks for the Qs!
All the best,
/birgül

DeDragoner t1_j6okrhi wrote on January 31, 2023 at 8:13 PM

How do you envision to implement this in vivo? There will be innumerable additional challenges (navigating 3D space, tissues etc.) How do you plan to reach tissues? A delivery by the bloodstream would cause heavy immun reactions.