Strong, reliable magnets play a hugely important role in much of the technology we benefit from today as well as in the production of the energy that animates such technology. With the premise that small size is often favourable, the magnet industry saw its most significant revolution during the 20th century with the development of rare earth element magnets (1970s). These afforded significant advancements from their inception and the development and subsequent refinement of magnets based on the element neodymium led to a new era of possibilities.
These Neo magnets, in their continually refined forms, are still the most powerful magnets we have developed. They have allowed the development of power steering; intense magnetic fields in MRI; head actuators in hard discs (that accurately position their arms to particular data tracks); magnetic components of headphones and loudspeakers; and a myriad of size-conscious electrical motors and generators.
These magnets, because of their strength, even carry unique hazards. A few cubic centimetres of Neo magnets is enough to cause serious injury to human tissue caught between them. This has even included cases of broken bones under their force. Magnets allowed to attract each other in free space can accelerate to such energetic velocities that they can shatter on impact, causing shrapnel-like injuries from resulting fragments. There is a current pressure in the scientific community to resolve the future of this area given that soaring demand, created in large by the requirement for high performance generators and motors that need far more magnetic material than most current applications, looks as though it will soon exceed the supply of neodymium we can achieve.