In this article, an electromagnetic actuator with a movable non-magnetic disc immersed in a ferrofluid that is exposed to a non-uniform magnetic field generated by permanent magnets is presented. The position of the levitated disc is stably controlled by the current in a command coil. Numerical simulations and experimental tests show that the actuator has linear transfer characteristics force versus current and displacement versus current. The device can ensure the highest ratio of force/size and the best energy efficiency for the actuators using a non-magnetic body immersed in a ferrofluid. Examples of possible applications are precision positioning systems and semi-active vibration dampers.
AndoBAsciaABaglioS (2009) A ferrofluidic actuator governed by AC fields. Sensors Letters7: 356–359.
2.
AndoBAsciaABaglioS (2010a) A ferrofluidic inclinometer in the resonant configuration. IEEE Transactions on Instrumentation and Measurement59(3): 558–564.
3.
AndoBBaglioSBeninatoA (2010b) Behavior analysis of ferrofluidic gyroscope performances. Sensors and Actuators A: Physical162(2): 348–354.
4.
AndoBBaglioSAsciaA. (2007) A novel ferrofluidic inclinometer. IEEE Transactions on Instrumentation and Measurement56(4): 1114–1123.
5.
DingZWeiPChitnisG. (2011) Ferrofluid-impregnated paper actuator. International Journal of Applied Electromagnetics and Mechanics20(1): 59–64.
6.
HartshorneHBackhouseCJLeeWE (2004) Ferrofluid-based microchip pump and valve. Sensors and Actuators B: Chemical99(2–3): 592–600.
7.
HatchAKamholzAEHolmanG. (2001) A ferrofluidic magnetic micropump. Journal of Microelectromechanical Systems10(2): 215–221.
8.
KimEGOhJChoiB (2006) A study on the development of a continuous peristaltic micropump using magnetic fluids. Sensors and Actuators A: Physical128(1): 43–51.
9.
LeeJHNamYJParkMK (2011) Magnetic fluid actuator based on passive levitation phenomenon. Journal of Intelligent Material Systems and Structures22(3): 283–290.
10.
LeeJHNamYJYamaneR. (2009) Position feedback control of a nonmagnetic body levitated in magnetic fluid. Journal of Physics: Conference Series149(1): 1–5.
11.
OlaruRDragoiDD (2005) Inductive tilt sensor with magnets and magnetic fluid. Sensors and Actuators A: Physical120(2): 424–428.
12.
OlaruRPetrescuCHertanuR (2010) Magnetic actuator with ferrofluid and non-magnetic disc. International Journal of Applied Electromagnetics and Mechanics32(4): 267–274.
13.
OlaruRSălceanuACalarasuD. (2000) Magnetic fluid actuator. Sensors and Actuators A: Physical81(1–3): 290–293.
14.
PetrescuCOlaruR (1999) Numerical determination of magnetic forces in ferrofluids. Revue Roumaine des Sciences Techniques – Série Électrotechnique et Énergétique44: 135–141.
15.
PetrescuCOlaruRHertanuR (2011) Study of a ferrofluid actuator with levitating nonmagnetic disc. In: Proceedings of the 7th international symposium on advanced topics in electrical engineering (ATEE-2011), 12–14 May, Bucharest, Romania, pp. 349–352. IEEE Publisher - Catalog Number CFP1114P-PRT, pp. 597–600.
16.
RosensweigRE (1985) Ferrohydrodynamics. New York: Cambridge University Press.
17.
RosensweigRE (1987) Magnetic fluids. Annual Review of Fluid Mechanics19: 437–463.
18.
SudoSTakakiYHashiguchiY. (2005) Magnetic fluid devices for micro machines. JSME International Journal, Series B48(3): 464–470.
19.
SudoSYanoTOkabeM. (2007) A study of micro magnetic fluid actuator. International Journal of Applied Electromagnetics and Mechanics25(1–4): 95–101.
20.
SunYKwokYCLeeF. (2009) Rapid amplification of genetically modified organisms using a circular ferrofluid-driven PCR microchip. Analytical and Bioanalytical Chemistry394: 1505–1508.
21.
UhlmannEBayatN (2003) Applications of ferrofluids in bearings and positioning systems. Production Engineering, WGP AnnalsX(1):125–128.
22.
UhlmannEBayatN (2004) Investigations on ferrofluidic positioning systems. Production Engineering, WGP AnnalsXI(2):195–198.
23.
UhlmannEBayatN (2006) High precision positioning with ferrofluids as an active medium. CIRP Annals – Manufacturing Technology55(1): 415–418.
24.
WonchulSJaegeunOBumkyooC (2006) Fabrication, experiment of a microactuator using magnetic fluid for micropump application. Microsystem Technologies12: 1085–1091.
25.
YamahataCChastellainMParasharVK. (2005) Plastic micropump with ferrofluidic actuation. Journal of Microlectromechanical Systems14(1): 96–102.
