Research departments


"ACEPI" TEAM :Acousto-electronics and Piezoelectricity

Acousto-électronique et Piézoélectricité

Team leader

Fabrice STHAL


Our ACEPI team’s focus area is single crystal piezoelectric materials. The team studies their fundamental properties but is also interested in their shaping and machining in view of applications for time-frequency.

The main objective is to design, build and characterize bulk acoustic wave resonators and electronic oscillators to be used for ultrastable time bases and/or sensor applications.


Goals and Research Areas

The ACEPI team’s main research topics are:

› Synthetic piezoelectric materials: investigations of synthetic piezoelectric materials (GaPO4, LGS, LG, etc.) as alternatives to quartz;

› Crystal defects: the study of the influence of crystal defects on the performance of quartz crystal resonators;

› Oscillators based on synthetic material resonators using langasite: noise measurements by oscillators with an integrated LGT resonator;

› Resonators at cryogenic temperatures: the behavior of energy-trapping acoustic resonators at cryogenic temperatures.

The stakes for society today

The challenge, concerning ultrastable frequency sources for telecommunications, aerospace or the military, is to move towards miniaturization, the maintenance (and improvement) of performance levels at a lower cost. High-performance sensors for measuring temperature, pressure, acceleration, etc. also present a major challenge to our knowledge of the environment.


In this highly specific focus area, unique in France, the team’s strength lies in its mastery over the entire process of development, from design/modeling, through production and finally to characterization. The Director of the MIMENTO technology center—in charge of the resource "Characterization and shaping of massive piezoelectric materials"—is also a member of the team.