Purdue University, www.purdue.edu

Researchers at Purdue University, West Lafayette, Ind., impregnated a piece of ordinary paper with a mix of mineral oil and nanoparticles of iron oxide. The result, dubbed Ferropaper, can be moved using a magnetic field, possibly making it useful in speakers, tweezers capable of moving a single-cell, low-cost micromotors for surgical instruments, and other applications. To make Ferropaper more durable, the researchers coated it with a biocompatible plastic film to make it water resistant and prevent the mineral oil and iron oxide mix from evaporating. The film also improves mechanical properties such as stiffness, strength, and elasticity.

Researchers made a small cantilever out of the new paper which moved or vibrated in a magnetic field. This could bring inexpensive alternatives to current cantilever actuators made from silicon, an expensive process that requires clean-room facilities.