How Is Barium Titanate Used To Make Microphones?
When people think of barium titanate, they are typically drawn to its capabilities as a ceramic for capacitors, due to its exceptional dielectric constant values.
Whilst this dielectric constant is the main reason why manufacturers come to specialist barium titanate suppliers time and again, there are other uses for the material as well, with one of the most unusual being its use in certain types of microphones.
There are a lot of different ways to make a microphone, from dynamic magnetic coil technologies to fibre optics, but one of the most popular types of microphone takes advantage of crystal piezoelectricity to convert vibrations into electrical signals, which are then interpreted as sound data.
The barium titanate or other ceramic material is a thin strip connected to a diaphragm, which acquires opposite piezoelectric charges when the diaphragm deflects them, and these electrical pulses can be fed to an output device or into a sound recorder.
Initially, the crystal of choice was potassium sodium tartrate, far better known as Rochelle salt, but the problem with this choice was that whilst it was very capable in terms of sensitivity it was also particularly vulnerable to moisture and would decompose at 55 degrees Celsius, which meant it needed more protection to survive for long stretches of time.
Barium titanate was far stronger and thus more capable than Rochelle salt in the long term, and for quite some time crystal microphones were a commonly included part of vacuum tube recording equipment due to their compatibility with vacuum tube inputs and relatively low cost.
Whilst they have since been supplanted by smaller condenser microphones and dynamic microphones, they do maintain a degree of popularity as contact microphones for acoustic instruments, as well as for recording sound in environments where other equipment simply cannot be used.
It serves to highlight that in the world of titanites, whilst there is a primary use a particular material is known for, there are also some fascinating alternative purposes.
