This thesis advances photoacoustic imaging (PAI) and cross-domain diagnostics through a compact platform that combines high-power LED excitation via avalanche transistor, multi frequency MEMS ultrasonic transducers, and ultra-low-power passive MEMS strain and displacement sensors.
On the optical side, a custom avalanche driver delivers high-intensity current pulses under 100 ns to near-infrared LEDs. This temporally confined illumination enables robust photoacoustic signal generation in both air and water, while significantly reducing cost and footprint compared to Q-switched lasers.
On the acoustic side, the MEMS transducers are designed to operate across multiple resonant frequencies ranging from approximately 0.3 to 8 MHz. This broadband response allows a single device to capture both high-resolution superficial details and deeper structural features.
Compact mechanical sensors enable deformation and motion measurements at microwatt-level power, facilitating motion compensation and optimization of acoustic coupling. A concentric ring sensor achieves displacement resolution of ~2 μm over a 20 μm range, with total power consumption of only 2.8 μW.
Future integrated prototypes could enable mechanically aware acquisition, paving the way for portable, low-power PAI systems, as well as reusable components for non-destructive testing, environmental monitoring, and wearable diagnostics.
These results lay the groundwork for a scalable, affordable, and reliable photoacoustic system, based on avalanche-driven LED excitation and multi-frequency mechanical MEMS detection. Keywords: Photoacoustic imaging, avalanche transistor pulse driver, high-power LED excitation, multi-frequency MEMS ultrasonic transducers, passive MEMS strain/displacement sensors, motion compensation, low-power imaging systems.
| Date | 16 Mar 2026 |
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| Original language | American English |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | Frédéric Nabki (Supervisor) |
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Prud Homme Buelna, A. (Author),
Nabki (Supervisor),
16 Mar 2026Student thesis: Doctoral thesis › Doctorate in Engineering: Engineering