New Technologies: Magnetic Ferropaper

Scientists at the Purdue University announce the creation of a new type of material that may become in the near future the basis of very small motors and robots. The magnetic ferropaper could be used in highly precise surgical tools, as well as in tiny robots, designed to navigate the intricate maze of the human circulatory system, for example. Miniaturized speakers and tweezers for the direct study of cells could also become possible relatively soon, the PU team believes.

The material itself is based on ordinary paper. The scientists say that even newsprint can be used. On this substrate, experts pour a special mixture, containing magnetic nanoparticles, most likely iron oxide, as well as mineral oils, which basically make the paper magnetic. This means that its motions and shape can be controlled via an external magnetic field. “Paper is a porous matrix, so you can load a lot of this material into it,” PU Electrical and Computer Engineering, and Biomedical Engineering Professor Babak Ziaie explains. The real, interesting thing about the new material is that the methods employed to create it are very cheap.

“Because paper is very soft it won't damage cells or tissue. It is very inexpensive to make. You put a droplet on a piece of paper, and that is your actuator, or motor,” the expert adds. The ferropaper can also be made water resistant, by enveloping it with biocompatible plastic films, to prevent any moisture from weakening it. The films play a dual role, as they also boost the paper's strength, flexibility and durability, the research team adds. Details of the new findings will be presented in Hong Kong between January 24-28, at the 23rd IEEE International Conference on Micro Electro Mechanical Systems.

The iron oxide particles are commercially available, and the equipment needed for producing this type of material is not very advanced. Therefore, even high-school students could make ferropaper in their chemistry labs, which could help promote the field of microrobots to more young people. “You wouldn't have to use nanoparticles, but they are easier and cheaper to manufacture than larger-size particles. They are commercially available at very low cost[s]. All types of paper can be used, but newspaper and soft tissue paper are especially suitable because they have good porosity,” Ziaie argues.