A ferrofluid has the fluid properties of a liquid and the magnetic properties of a solid. The ferrofluids actually containtiny particles (around 10 nmdiameter) of a magnetic solid suspended in a liquid medium. To keep them small, magnetic and van der Waals interactions must be overcome to preventthe particles from agglomerating. Thermal motion of magnetite particles smaller than 10 nm in diameter is sufficient to prevent agglomeration due tomagnetic interactions.
Ferrofluids were originally discovered in the 1960s at the NASA Research Center, where scientists were investigating diferent possible methods ofcontrolling liquids in space and applied to wide field at present.
For example, Semiconductor, LCD, Solar cell and PLED etc.
Magnetic fluid seal
A frroluid can behave as a liquid 0-ring where a rotating shaft enters either a low- or high-pressure chamber. The ferrofluid is held in place bypermanent magnets and forms a tight seal, eliminating most of the friction produced in a traditional mechanical seal .
Application for magnetic fluid seal
Wafer growing equipment
Semiconductor process equipment (Epitaxy, Difusion, CVD, PVD, Implantation etc)
LCD process equipment Vacuum Robot Solar cell
Common Application Specifications
Ultimate vacuum: 10° Pa(10~ 8 Torr)
Helium leak rate : Less than 1 3x10 12 Pa.m3/sec(10" Torr-/sec)
Differential pressure : 2.5kg/cm2( .5 atmosphere)
Operating temperature :0C to 200C ( In case of high temperature should apply to cooling system.,)
Gas compatibility : Active and Reactive Gas
Materials of housing and shaft : SUS303, SUS304, and SUS630, etc