Characterization of CMUTs

Project work: Monday, May 29, 13.00-17.00; Tuesday, May 30, 08.00-12.00 and 13.00-17.00; Wednesday, May 31, 13.00-17.00 in the group rooms Building 349, Ground floor Project presentation preparation is Thursday from 8:00-12:00, and the presentations are from 13:00-17:00.

Purpose

The purpose of this project is to learn how to characterize CMUTs electrically and acoustically. CMUTs are capacitive transducers, and they are fabricated using micro and nano silicon-based fabrication. Before mounting in a probe, they are characterized electrically to assess their performance. Based on this the best chips are selected and then mounted in an ultrasound probe. Once the CMUTs are packed, acoustically measurements in water can be performed to find the TX and RX sensitivities and to determine the bandwidth of the transducers.

Project work

1. Project work I: Read the material listed below and prepare questions that we can discuss when we meet to Project work II.
2. Project work II: We meet in building 344-115 where the experiments take place. We will prepare the measurements and you will learn how to operate a wafer level prober to perform electrical characterization.
3. Project work III: We meet in building 344-115 where we will perform the electrical test of the CMUTs.
4. Project work IV: We meet in building 344-115 where we will perform the acoustical characterization.

Papers and reading material:

• The lecture note: Erik V. Thomsen: Capacitive Sensors DTU, 2022. to learn how capacitive transducers work
• Chapter 1 and 9 in the PhD thesis by Rune Sixten Grass: Micromachined Integrated 2D Transducers for Super Resolution Ultrasound Imaging DTU helth Technology, 2022, to learn about CMUTs in general and how to characterize them.

Dissemination:

Make a 10 minutes presentation of your project, which will be discussed on Thursday, June 1 from 13:00. There is 15 minutes available for each project group.