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.
磁流體最初于20世紀69年代在美國國家航空和宇宙航行局研究中心被發現。也就是在那個研究中心，科學家們正研究在太空中控制液體的可能方法，并至今運用到更寬泛的領域。
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.
例如，半導體，液晶顯示屏，太陽能電池，高分子發光二極管等。
For example, Semiconductor, LCD, Solar cell and PLED etc.
磁流體密封
Magnetic fluid seal
磁流體可以作為一個液體0型圈，在這里面一個轉軸進入到一個低壓或者高壓的腔體。磁流體被永磁體固定住，并形成緊密密封，以消除在傳統機械密封中產生的大部分的摩擦。
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 .
磁流體密封的應用
Application for magnetic fluid seal
-.晶圓制造設備
Wafer growing equipment
-.半導體工藝設備(外延附生，擴散，化學汽相淀積，物理氣相沉積，植入等)
Semiconductor process equipment (Epitaxy, Difusion, CVD, PVD, Implantation etc)
-.液晶顯示屏工藝設備 -.真空機器人 -.太陽能電池
LCD process equipment Vacuum Robot Solar cell
常見應用規范
Common Application Specifications
●極限真空: 10-6 Pa(10-8托)
Ultimate vacuum: 10° Pa(10~ 8 Torr)
●氦泄漏率:少于1.3x10-12Pa.m3/秒(10-11Torr.I/秒)
Helium leak rate : Less than 1 3x10 12 Pa.m3/sec(10" Torr-/sec)
●壓差: 2.5kg/cm2(.5大氣)
Differential pressure : 2.5kg/cm2( .5 atmosphere)
●操作溫度: 0°C 到200°C (如遇高溫，采用冷卻系統)
Operating temperature :0C to 200C ( In case of high temperature should apply to cooling system.,)
●氣體兼容性:活性氣體和反應氣體
Gas compatibility : Active and Reactive Gas
●外殼和轉軸的材質: SUS303, SUS304, SUS63等
Materials of housing and shaft : SUS303, SUS304, and SUS630, etc