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An Experimental Protocol for Assessing the Performance of New Ultrasound Probes Based on CMUT Technology in Application to Brain Imaging
Published on: September 24, 2017
Capacitive micromachined ultrasonic transducers (CMUTs) with isolation posts.
Yongli Huang1, Xuefeng Zhuang, Edward O Haeggstrom
1Kolo Technologies Inc., San Jose, CA, USA.
Ultrasonics
|January 22, 2008
Summary
This study introduces improved capacitive micromachined ultrasonic transducers (CMUTs) using isolation posts. This design enhances reliability and enables repeatable operation beyond the collapse voltage.
Area of Science:
- Microelectromechanical Systems (MEMS)
- Acoustic Transduction
- Ultrasonic Devices
Background:
- Capacitive micromachined ultrasonic transducers (CMUTs) face reliability challenges, particularly concerning contact (collapse) voltage limitations.
- Conventional CMUT designs often employ full-coverage insulation layers, leading to contact voltage drifting due to charge accumulation.
Purpose of the Study:
- To present an improved CMUT design addressing reliability issues.
- To extend the operational range of CMUTs beyond the conventional collapse voltage.
- To enhance the repeatability of CMUT performance in the post-contact regime.
Main Methods:
- Introduction of isolation posts within the vacuum cavities of CMUT cells.
- Elimination of full-coverage insulation layers in favor of the novel isolation post design.
- Comprehensive ultrasonic testing, including electrical impedance and capacitance measurements in air, and transmission/reception tests in immersion.
Main Results:
- The novel isolation post design (PostCMUTs) effectively eliminates contact voltage drifting.
- Repeatable CMUT operation is achieved in the post-contact regime.
- Ultrasonic performance in both air and immersion is comparable to conventional CMUTs, with no observed adverse side effects.
Conclusions:
- The isolation post design represents a significant advancement in CMUT reliability.
- This improved design broadens the operational capabilities of CMUTs.
- PostCMUTs offer a promising alternative for applications requiring robust and stable ultrasonic performance.
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