[Li Zhang] And his colleagues at the Chinese University of Hong Kong (CUHK) have created a guru blob that can navigate complex environments, raise an ‘arm’, grab a wire and move it, enclosing a small object. As explained in the research paper, it is a secret that bots are made of non-Newtonian material.
You can make a similar spell at home with corn starch and water, usually called “slime”. Gradually distorted, it will move like a liquid. Quickly deformed, it behaves like an elastic solid. Versions of CUHK include polyvinyl alcohol, glass coated NdFeB microparticles (neodymium magnets), and borax.
This dual behavior allows the robot to do amazing things. Positioned on a surface, they are pulled down by a magnet to extend the blob to the pseudopods, then grasp it using a circular field and transport a wire. They used a similar technique on another axis to swallow an object. The CUHK group is promoting it as a way to recover foreign objects from the body (such as an accidentally swallowed button cell).
Nd magnets are made by synthesizing Nd2O3 or NdFeB in a strong magnetic field. Nd2O3 is available from SigmaAldrich with little tears. Polyvinyl alcohol and borax are readily available. This sounds like a hobby work-capable project (nd toxic, be careful).
We’ve been covering micro robots for some time. In 2014 we covered a swarm of micro robots. This project uses an external field to move a small Nd magnet and in 2014 we covered the early work of this field.