Title: Integration of polyvinylidene fluoride onto complementary metal-oxide-semiconductor chips
Description: Research in biology and medicine depends heavily on what we can measure. Photoacoustic imaging techniques allow for imaging both structural and functional information simultaneously. Current photoacoustic imaging technology is limited by either the speed at which the images are formed or resolution of the images. By increasing the resonant frequency at which the transducers receive photoacoustic signals, the resolution of a photoacoustic tomography setup can be improved without compromising on imaging speed. Due to their size, the resulting transducers must be placed directly onto a complementary metal-oxide-semiconductor (CMOS) integrated circuit (IC). This thesis describes a fabrication flow and electronics design that opens the door to high speed, high resolution photoacoustic imaging. A microfabrication flow is developed to place high frequency polyvinylidene fluoride transducers onto an integrated circuit. A 1-D array of transducers are fabricated and characterized on a CMOS IC. The custom IC (TSMC 90 nm) is designed to amplify the signals coming from the small transducers using a proposed two-stage LNA.

The circuit is electrically characterized before and after transducer fabrication showcasing the CMOS-compatible nature of the fabrication flow. The transducers and integrated circuit are characterized in a photoacoustic setup using two phantoms to verify the functionality of the system. Compared to similar systems, this system displays monolthically integrated transducers that receive broadband responses centered at 35 MHz with 140 bandwidth.