Comments below this answer have inspired this quesiton.
Wikipedia's Ferrofluidic seal sez:
Ferrofluid-sealed feedthroughs routinely operate in environments including ultra-high vacuum (below 10⁻⁸ mbar), temperatures over 1,000 °C, tens of thousands of RPM, and multiple-atmosphere pressures.
Are ferrofluidic seals used in spaceflight? If so:
- What are the main applications
- Are they used in human-rated applications, i.e. to seal an atmosphere being breathed by humans against loss to space?