What is Bubble Memory ?
Bubble memory is a type of non-volatile memory that makes use of a thin layer of magnetic material that holds small magnetized areas known as bubbles or domains, which are able to store one bit of data each. The magnetic material is arranged into parallel tracks where the bubbles can move along through the action of an external magnetic field. Bubble memory was a promising technology in the 1980s, offering similar density to hard disk drives and similar performance to core memory, but major advancements in both hard disk and semiconductor memory chips pushed bubble memory into the shadows.
Bubble memory is also known as magnetic bubble memory.
Bubble memory was invented in Bell Labs in the 1970s by Andrew Bobeck who also worked on magnetic core memory and twistor memory. Both projects actually led Bobeck to come up with bubble memory. Using the orthoferrite and magnetic materials used for twistor memory, and by storing data in patches and then applying a magnetic field to the entire material, these patches could be shrunk down into tiny circles that Bobeck called bubbles. These bubbles are then moved from one edge to the next via “tracks” and then read at the other edge by a conventional magnetic pickup. These bubbles were also very small compared to the domains in contemporary media, such as magnetic tape, thus hinting at the possibility of higher densities.
Because of its properties – it has storage drives with densities similar to hard drives, but with the performance of core memory – it was slated to be the next generation of general memory that could fill both primary and secondary storage roles. However, the technology was not quick enough to evolve, and the manufacturing process was still expensive and complicated. It was overtaken by hard drives and semiconductor memory. Bubble memory was no longer being manufactured and sold within 10 years of its development, having been replaced by the HDD and DRAM in the 1980s.