In 1839 Earnshaw [1] proved that no stable equilibrium is possible if particles interact according to Coulomb's law. Later Lord Kelvin [2] showed that diamagnetic materials represent an exception: for them, stable equilibrium is possible. It is energetically favorable for a diamagnetic body to stay in a magnetic field minimum, with a restoring force proportional to the gradient of the magnetic energy density. In 1939 Braunbek$ [3] published a detailed study of diamagnetic levitation. He experimentally observed the levitation of graphite and bismuth. In the Braunbek experiment the maximum field variation was about 2.4T over the distance of 2mm. Recently experimental studies of levitation have been performed by Geim and coworkers [4-6], including living species. A brief review on diamagnetic levitation is given in Ref.6. The history of levitation together with levitation experiments is discussed in the excellent site founded by Andre Geim.

We have suggested [7] that by using magnetic micro/nanostructures, magnetic field minima can be made in a variety of shapes and sizes, thus creating different types of traps, localized or extended. This approach has been described in details in work [8] where we reported the direct trapping of single micron-size polystyrene microspheres (beads) inside a paramagnetic buffer solution, by a field created by permanent micromagnets. First these results vere reported on NSF NIRT conference in December 2002[10]. Then on APS March meeting in March 2003. The restoring magnetic force in such traps can be three orders of magnitude larger than the gravitational force. In a recent work [9] we report diamagnetic levitation in air of droplets and/or particles of pico-femtoliter volume and demonstrate their on-chip storage and high precision manipulation (translation, merging, assembling and rotation). First report was presented on NSF NIRT conference in December 2003 [11]

On page Microfluidics we present our results on manipulation of the diamagnetically levitated droplets/particles and processing them on a Magnetic Micromanipulation Chip (MMC). These results are published in [9].

The page Resolving Femtonewtons discuss measurement of forces acting on levitated droplets. This is possible to perform with (sub)femtonewton resolution. This stuff is also published in Ref.[9]. The page also shows unpublished results and movies.

The page Traps for Cells presents results on trapping (sub)micron size beads in magnetic trap with paramagnetic buffer solution published in [8]. It also presents unpublished results on trapping red blood cells in the same trap.

The page Simply Fun is a collection of movies (with audio track) which display in more "edutainement" way results presented on previous pages.

1. S. Earnshaw, On the nature of the molecular forces which regulate the constitution of the luminiferous ether, Trans. Camb. Phil. Soc., 7, 97-112 (1839).

2. W. Thomson, Reprint of Papers on Electrostatics and Magnetism MacMillan, London, 1872, paper XXXIII, pp. 493-499, and paper XXXIV, pp. 514-515.

3. W. Braunbek, Z.Phys., 112, 753-763 (1939); Z.Phys., 112, 764-769 (1939);

4. A.Geim, Physics Today, Sep.1998, page 36-39

5. M.V.Berry and A.K.Geim, European Journal of Physics, v. 18, p. 307-313 (1997).

6. M.D.Simon, L.O.Heflinger and A.K.Geim, Am. J. Phys., v. 69, pp. 702-713 (2001).

7. I. F. Lyuksyutov, Mod. Phys. Lett. B v. 16, 569 (2002). Text

8. I. F. Lyuksyutov, A. I. Lyuksyutova, D. Naugle and K.D.D. Rathnayaka Mod. Phys. Lett. B v. 17, 935 (2003). Text

9. I. F. Lyuksyutov, D. G. Naugle and K.D.D. Rathnayaka Appl. Phys. Lett. v. 85, 1817 (2004). Text

10. NSF Nanoscale Interdisciplinary Research Team (NIRT) Highlights 2002 NIRT Highlights 2002 Text

11.NSF Nanoscale Interdisciplinary Research Team (NIRT) Highlights 2003 NIRT Highlights 2003 Text