Ferrofluid-Impregnated Paper Actuators

In this paper, we report on an inexpensive method of fabricating miniature magnetic actuators using ferrofluid impregnated paper. Different types of papers (including soft tissue paper, cleanroom paper, Whatman-1 filter paper, printer paper, and newspaper) were loaded with oil-based ferrofluid, microma-chined by a CO 2 laser and coated with a thin layer of parylene-C. The soaking capability of the different papers was investigated, with the soft tissue paper having the highest loading capacity, being able to absorb ferrofluid by as much as six times its original weight. Cantilever actuators fabricated from cleanroom and filter papers were able to generate the largest force (>; 40-mg equiva lent force), whereas the soft-tissue-paper cantilevers provided the greatest deflection (40° tip angle).