According to a Purdue University news release, researchers there have created a magnetic material they call ferropaper which they believe can be used to create tiny, low-cost micromotors, speakers, and even robots. To make the material, they start with conventional paper and impregnate it with ferrofluid, a mixture of mineral oil and magnetic nanoparticles made of iron oxide. The paper is then coated with a "biocompatible plastic film" to make it water resistant. Newspaper and tissue paper have proven best for creating ferropaper. Inexpensive materials are one of the advantages of ferropaper over existing technologies, explains Babak Ziaie:
Cantilever actuators are very common, but usually they are made from silicon, which is expensive and requires special cleanroom facilities to manufacture. So using the ferropaper could be a very inexpensive, simple alternative. This is like 100 times cheaper than the silicon devices now available
The complete research findings on ferropaper will be presented at the upcoming 23rd IEEE International Conference on Micro Electro Mechanical Systems, Jan 24-28, in Hong Kong.