Microtubules-like microrobot assembly

What is it about?

Sparked by Fantasy Voyage, a sci-fi film in 1966, scientists’ fantasy of tiny nano/microrobots that can go inside our bodies and kill cancers has never stopped ever since. Huge progress has been made in recent years. Tiny nano/microrobots, that can be as small as a millionth of a human hair, can propel, sense, carry drugs, and push many steps closer to final dreams. As expected, a swarm of hundreds and thousands of such nano/microrobots can be more beneficial with collective motions that can help counter against blood flows, enhance drug delivery efficiency, and get better imaging signals that can make those robots seen under X- ray, MRI, ultrasounds, etc. In this study, scientists explored a better way to organize microrobot swarms. Instead of irregular 3D aggregates usually observed, they have found that hollow microtubes like microtubules can be assembled from a simple, unorganized suspension of microspheres and all can be done with tuning magnetic fields generated from ordinary speaker coils. These microtubes can propel as microrobots with propulsion velocities and directions precisely controlled by external magnetic field. The hollow inner spaces make propelling tubular bots viable for cargo capture and transport. The structural stability ensures microrobots to even be compressed and uncompressed repeatedly along radical direction without breaking up and reversible compression on cargoes like red blood cells, thereby achieving a unique capacity that can help to in-situ physical property detection.

Featured Image

Photo by jean wimmerlin on Unsplash

Photo by jean wimmerlin on Unsplash

Why is it important?

The assembly method introduced in this study is universal as long as the particles are superparamagnetic, and we have demonstrated it with particles ranging from 200 nanometers to 30 microns. What is more, all the assembly and manipulations are achieved with weak external magnetic field which is biocompatible and can be easily implanted with existing biomedical apparatus without major modifications. After all, all we need are coils that have been seen from high school physics classes.