SEMINAR: High-Density CMOS-Based Ultrasound Phased Array for Photoacoustic Imaging: From Concept to In-Vivo Validation

Guest: Volkan Arslan, Columbia University

Title: High-Density CMOS-Based Ultrasound Phased Array for Photoacoustic Imaging: From Concept to In-Vivo Validation (EE, ME, BIO, PHYS, MAT)

Date/Time: 25 November 2025, 14:40

Location: FENS L067

Abstract: Photoacoustic imaging (PAI) is an emerging biomedical modality that combines optical excitation with ultrasound detection, enabling high-contrast visualization of tissue structures beyond the capabilities of traditional ultrasound, while offering substantially deeper penetration than purely optical imaging techniques. However, realizing the full potential of PAI requires spatial resolutions that exceed the limits of conventional ultrasound phased arrays, which typically deliver millimeter-scale resolution. This talk presents a co-design strategy that integrates a custom 206-channel CMOS platform with monolithically fabricated polyvinylidene fluoride (PVDF) transducers for high-resolution photoacoustic imaging. By reducing interconnect lengths, lowering capacitive parasitics, and minimizing the input capacitance of receiver amplifier circuits, the resulting monolithic CMOS architecture enables high-fractional-bandwidth transduction. To support this performance, individual PVDF transducers have the dimensions of 30µm x 25µm x 5.5µm, volumetrically over two orders of magnitude smaller than ceramic piezoelectric transducer arrays. The system’s performance is demonstrated through both in-vitro and in-vivo imaging experiments, achieving lateral and axial resolutions better than 30 μm and 15 μm, respectively. These results demonstrate a scalable pathway toward CMOS-integrated ultrasound and PAI systems suitable for wearable, implantable, and minimally invasive biomedical applications.

Bio: Volkan Arslan received the B.S. degree in Electronics Engineering with a minor in Physics from Sabancı University, Istanbul, Türkiye, in 2019, and the M.S. degree in Electrical Engineering from Columbia University, New York, USA, in 2020. He defended his Ph.D. in Electrical Engineering at Columbia University in October 2025 and is currently completing his final semester. His research mainly focuses on high-density CMOS-based ultrasound phased arrays for high-resolution photoacoustic imaging applications.