Research & development - Leuven | More than two weeks ago
Design, implementation, and miniaturization of read-out system for Micromachined Ultrasound Transducers for imaging applications
The MEMS team of Imec Leuven is developing Piezoelectric Micromachined Ultrasound Transducers for a multitude of ultrasound applications. Currently, classical ultrasound transducer consist of a thick layer of piezo material, sandwiched between two electrodes. Their miniaturized counterparts (PMUTs) allow for a much smaller form factor and easier integration with supporting electronics. Therefore, PMUTs have the potential to revolutionize the field of Ultrasound applications and open new applications such as: haptic feedback, gesture recognition and long-term medical monitoring with wearables. The last application forms the basis for this master thesis topic.
PMUTs are miniaturized drums containing a piezoelectric layer in a membrane that can generate and pick-up mechanical deformation of the suspended membrane. This allows PMUTs to emit and receive ultrasound waves by respectively vibrating the membrane or detecting the deformation of the membrane by an incoming wave.
Fig 1: Sketch of PMUT cross-section and working principle.
By using smart arrays of these small transducers and controlling them in an organized manner, complex ultrasound fields can be generated and received. It is this beamforming feature of arrays of transducers that allows ultrasound imaging.
In this work, the goal is to optimize and implement a wearable ultrasound transducer system consisting of PMUTs and supporting electronics on PCB. The investigation will entail a co-optimization of ultrasound and electronics in the smallest possible form factor. Depending on the student’s interest, the work will be steered towards the ultrasound or electrical part of the system. The resulting prototype will be used to demonstrate medical imaging for wearable applications. In figure 2 a conceptual sketch is displayed, giving an example of the use and form factor of such a wearable, here to monitor the spine position in humans:
Fig 2: Sketch of ultrasound wearable for spine tracking.
Therefore, the work will consist of: gaining understanding of the PMUTs and ultrasound, possibly ultrasound simulations, electrical and acoustic characterization, PCB design with off the shelve components, building of prototypes, measuring functionality and finally converging to a PCB with small form factor and good read-out SNR. The challenge will be to integrate the read-out of multiple channels in a small form factor and match the PCB to the PMUTs’ characteristics. The work is estimated to be: 40% simulations/design (which can be both ultrasound and/or electrical simulations), 30% characterization, 30% implementation. Generally, this is a topic for a student who is eager to understand complex systems with a hands-on attitude and interest for MEMS devices.
Type of project: Internship, Thesis, Combination of internship and thesis
Duration: 6 months - 1 year
Required degree: Master of Engineering Technology, Master of Engineering Science, Master of Bioengineering
Required background: Physics, Nanoscience & Nanotechnology, Electrotechnics/Electrical Engineering, Electromechanical engineering, Biomedical engineering
Supervising scientist(s): For further information or for application, please contact: Veronique Rochus (Veronique.Rochus@imec.be) and Margo Billen (Margo.Billen@imec.be) and Piotr Czarnecki (Piotr.Czarnecki@imec.be)
Only for self-supporting students.