Cutting the Drive Voltage by almost one Order of Magnitude
In order to generate ultrasound with piezo transducers, operation at resonance is required for most applications. At resonance, power requirements are minimized as the amplitude reaches a maximum. High-Q piezo ceramic materials with low internal damping are needed to enable resonant operation.
Multilayer piezo transducers consist of many thin layers (typically 10’s of microns) of active ceramics produced in a tape casting process. Screen printed electrodes between the layers are co-fired with the ceramics in one step. The advantage here lies in the reduced operating voltage and the simplicity of integrating the piezo elements into a mechatronic system.
Until recently, multilayer piezo transducers were mainly used for precision positioning and fast switching / dosing applications with operating frequencies typically in the hundreds to few 1000’s of Hz.
Multilayer piezo elements are usually manufactured of so-called soft PZT materials, with high internal damping, making operation at resonance not feasible.