Ultrasonic transducers and sensors

Through this research operation, the team focuses on emerging technologies and integration of new materials in devices, for which its know-how has been recognized by the scientific community such as new piezoelectric lead-free materials (including KNN, BCTZ, AlN), cMUTs and periodically structured media. The targeted applications are biomedical imaging, therapy, non-destructive evaluation and SAW sensors. Several phenomena are taken into account such as the electromechanical coupling (piezoelectric or electrostatic), the influence of the environment (electrical and mechanical boundary conditions, such as cMUTs/substrate, cMUTs/fluid interactions, periodicity, ...), crosstalk between cells or elements (piezoelectric array transducers, cMUTs). The design of these devices is carried out with the constant concern of optimizing the choices in terms of active materials and/or substrates, and to study their influence on the performance of the final device.

Tools and methods

The team proceeds with the design of tools based on analytical or numerical models – fabrication processes - acoustic characterisation (vibration measurements, radiation patterns, ...), integration in systems such as ultrasound scanners for performance evaluation.

New piezoelectric transductors for imaging

DISCUS OR2 Image 1 High frequency lead-free probe (20 MHz) for medical imaging
(collaboration with VERMON)


DISCUS OR2 Image 2 Comparisons of ultrasound images of a human forearm skin acquired with a 20MHz piezoelectric lead-free probe and a commercial PZT probe.

High frequency annular array (>30 MHz) based on a piezoelectric copolymer (PVDF-TrFE) on Silicon mounted on a PCB
High frequency annular array (>30 MHz) based on a piezoelectric copolymer (PVDFTrFE) on Silicon mounted on a PCB (collaboration with IRLYNX).


 

Investigation of phononic crystals and metamaterials: new process for crosstalk reduction

Study of crosstalk in a phononic piezoelectric plate

Study of crosstalk in a phononic piezoelectric plate: the application of particular conditions to the electrodes (here open circuit / short circuit) leads to the opening of the hybridization gap.
(Collaboration with LOMC, Le Havre).

Capacitive micromachined ultrasonic transducers (cMUT) for imaging and therapy

DISCUS OR2 Image 3
cMUT probe with bimodality for imaging and therapy.



DISCUS OR2 Image 4
Vibratory measurment of a cMUT cell.