That will depend on the size, shape, crystal orientation and magnitude of disturbance impacting the crystal. Typical output for resonant knock sensors as an example will be .01 to .1 volts rms with peak voltages reaching 3 to 10 volts at frequencies between 2.5 to 4k Hz.

Ultrasound equipment, sonars, guitar pick-ups, flow-meters (certain types), buzzers (door bells, smoke detectors, alarms etc.).

Piezoelectric roads are special type of roads, which generates electricity when vehicles passes over it.
This phenomena can be understood by piezoelectric effect…
Piezoelectric Effect - Piezoelectric effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress.
Simply, These type of material produce electricity, when any kind of mechanical stress/force is applied on it…

During vibration energy harvesting, piezoelectric materials convert mechanical strain into an electrical charge or voltage via the direct piezoelectric effect. Extrinsic factors comprise of the input vibration frequency, acceleration of the base/host structure, and the amplitude of the excitation.

Environmental pollution has been one of the main challenges for sustainable development. Piezoelectric materials can be used as a means of transforming ambient vibrations into electrical energy to power devices. The focus is on an alternative approach to scavenge energy from the environment.

Harvesting methodologies to evaluate the potential effectiveness of different techniques and provides an overview of the methods and challenges of harvesting energy using piezoelectric materials.

Piezoelectric energy harvesters have many applications, including sensor nodes, wireless communication, microelectromechanical systems, handheld devices, and mobile devices.

Piezoelectric energy harvesting also uses the impact of raindrops. The energy harvesting model presented is further analyzed for single-unit harvester and an array of multiple harvesters to maximize the efficiency of the device.

Yes of course but as we are seeing our roads quality is itself is very poor and it would take long time for the idea to come into practice. Many countries are still trying to implement this but the initial cost being very high on research it is not coming not practice on immediate go. But the results are terrific once it comes into live

No. Applying pressure to a piezoelectric material generates charges on its surface. In this state, the piezoelectric element behaves very much like a charged capacitor. It will discharge when connected to a load, in a couple of milliseconds. In order to keep on extracting electrical energy, one has to constantly re-apply pressure to the material, that is, to make it vibrate. This is why people spend time developing piezoelectric devices that exploit sources of mechanical vibrations such as roadways, footsteps, raindrops, wind and so on.

The amount of polarization generated and hence the potential difference generated in a piezoelectric device depends on the amount of the stress applied since they are directly proportional to each other. This is because more the tensile force you applied which is parallel to the direction of polarization, the polarization vector will extend because of increasing separation between opposite charges. Therefore, in order to generate more potential, one has to apply high stress levels. It also depends upon the piezoelectric charge constant (d). The first discovered piezo crystals such as quartz have a smaller constant value and therefore, only generate small amount of charge whereas now a days, modified Lead zirconia titanate (PZT) can generate considerably high amount of potential depending upon the type of domant that is used. Also, it depends on the structure of the PZT; for example rectangular plate or a disc ( disc has a high electromechanical coupling factor) and hence will generate more charge, or we can have single plate or a stack of PZT plates know as multilayer PZT which has a higher efficiency than the single plate.

Thus, there are many factors which are responsible for charge and hence potential generation in piezoelectric devices which should be taken into consideration for the final output.