Injection-molded physical unclonable function
A physical unclonable function is disclosed. A highly random distribution of magnetic particles within a thermoplastic polymer is created by magnetizing magnetizable particles in solid pellet feed material before feeding the solid pellets into an injection molding machine. Other devices and processes are disclosed.
1. A method of manufacturing a physical unclonable function comprising:
combining plastic and magnetizable particles that are not magnetized to make a feed material, wherein the magnetizable particles contain neodymium, iron, and boron;
forming the feed material into solid pellets;
magnetizing the particles in the solid pellets to make pre-magnetized solid pellets;
feeding the pre-magnetized solid pellets into an injection molding machine; and
forming the pre-magnetized solid pellets into an injection-molded physical unclonable function.
2. The method of claim 1 , wherein the solid pellets contain between ten and twenty percent, inclusive, by weight of magnetizable particles.
3. The method of claim 1 , wherein after feeding the pre-magnetized solid pellets into an injection molding machine, the magnetizable particles are heated to below the Curie temperature of the magnetizable particles.
4. The method of claim 1 , wherein the magnetizable particles are flakes.