I am planning on making a musical instrument where I require the conversion of vibration of a material to voltage. The idea is to make a percussion instrument where I hit a plate made of a certain type of material. Based on the different areas on which I hit the plate, the vibrations will be different and after converting the vibrations to voltage, I will take the FFT of the signals to differentiate the different areas on which I hit the material and map it to produce a particular sound. I know that piezoelectric sensor is a material which converts pressure to voltage but I am not sure if it will be robust enough. Is there any alternative I can use?
What you plan seems very difficult to achieve. You are talking about different vibrations when you hit different places. What do you think will be different? Sound loudness level or sound frequency? If you go with frequency, then a microphone would be your device. Measuring sound loudness differences in a hard material is very hard to achieve, because it is a very tiny difference.
It seems you would like to correlate position of impact on the striking surface to frequency. The mic followed by appropriate signal processing will produce the time, frequency, and amplitude. A second sensor system is needed to determine point of impact.
As you mentioned, piezo might work, but I suspect this would require an array of sensors rather than a single sensor. Another thought might be to surround your striking surface with an array based on optical touch sensor technology such as this and shown in the illustration below.