Scientists use magnetic nanotech to safely rewarm frozen tissues for transplant
phys.org
phys.org
> Methods have been developed to quickly freeze organs for longer-term storage without risking damage from ice crystal formation, but ice crystals can also form during warming. To address this problem, Yadong Yin and colleagues advanced a technique known as nanowarming, pioneered by collaborator John Bischof, to employ magnetic nanoparticles and magnetic fields to thaw frozen tissues rapidly, evenly and safely.
Probably very stupid question, but can this be used also for cooling? Let the nanoparticles absorb some heat, then use a magnetic field to align them, then repeat?
Like a Peltier element but remotely…
A ferromagnetic material that is placed in an alternating magnetic field is heated by the so-called hysteresis losses, which happen when the material is magnetized, demagnetized and remagnetized. This can be seen e.g. in an electric transformer with a ferrite core, where the transformer core will become hot during operation (the iron cores used in low-frequency transformers are also heated by eddy currents, like an induction stove, but ferrites are insulators, so they are heated only by hysteresis losses).
Because the magnetite nanorods are anisotropic, the heat produced will depend on their orientation vs. the alternating magnetic field.
This is used to modify the heating rate, but there is no way to do cooling.
There exist magnetic refrigerators, which are based on the magnetocaloric effect, but they use very different magnetic materials, e.g. based on gadolinium or other rare-earth metals. Those are efficient only at extremely low temperatures, close to zero kelvin, so they would be useless for freezing animal tissues.
Long way to go yet though. So, we bring - let's say - Disney back. How do we reanimate? Apart from, of course, curing what killed them.-
Bad news: Now you're dying of metallic nano-particle poisoning
Lots of dead people are going to wake up in horror simulators. Or as Tamagotchi.
Not being able to hit Pause on a medical issue will probably seem on par with doing healthcare without antibiotics. We simply happen to live in the years before that.
...damn