Project: Photoacoustics

The project "Optoacoustic Sensing" aims to develop novel, highly integrated, and miniaturized ultrasound detectors for photoacoustic imaging and to evaluate their practical applicability. The focus is on CMOS-compatible capacitive ultrasound transducers (CMUTs).

CMUTs address central requirements of modern medical technology: miniaturization, high sensitivity, integration with electronics, and compatibility with cost-effective mass production.

Application Field & Motivation

In modern medical diagnostics, photoacoustic imaging is becoming increasingly important. It combines optical excitation with acoustic detection, enabling functional images, e.g., for depicting metabolic processes or inflammatory tissue changes. To apply this technique in deeper body regions such as the prostate or intestines, miniaturized and integrable detectors are necessary.

Current piezoelectric ultrasound detectors, however, are not CMOS-compatible and can only be limitedly miniaturized. This is where Fraunhofer IPMS comes in with the development of CMUTs, which are manufactured using microsystem technology and are ideal for highly integrated, portable sensor platforms.

Our Technology: CMUTs made at Fraunhofer IPMS

CMUTs are micromechanical devices that convert acoustic waves into electrical signals via electrostatic coupling. Fraunhofer IPMS has many years of experience in the development and manufacturing of this technology:

• Over 8 years of expertise in CMUT process development
• Production in a modern 200-mm CMOS-compatible cleanroom
• Flexible structure sizes in the micro and nanometer range
• Scalable multi-channel arrays for high resolution
• Integrability with electronics and other components

In the project, the CMUTs will be assembled in a demonstrator system and characterized in terms of their reception properties, bandwidth, and signal stability. Additionally, measurement algorithms for signal processing and image reconstruction will be developed.

Added Value & Perspective

By combining years of MEMS expertise with modern system integration, Fraunhofer IPMS makes a significant contribution to the development of the next generation of photoacoustic detectors in the project. The CMUTs manufactured at IPMS enable compact, high-channel, and simultaneously highly sensitive receiving units, which are ideal for use in portable or catheter-based medical systems. Thanks to CMOS-compatible manufacturing processes, these components can be directly integrated with electronic circuits, a crucial advantage for realizing cost-effective and mass-producible overall systems. Moreover, the technologies and integration concepts developed in the project will form the basis for future industrial collaborations and aim to facilitate the transfer into application-oriented products and clinical systems. This positions Fraunhofer IPMS as a central partner for innovative solutions in ultrasound and photoacoustic medical technology.