A 30 MHz, 3D Imaging, Forward Looking Miniature Endoscope Based on a 128-Element Relaxor Array

This work describes the design, fabrication and characterization of a 128-element crossed electrode array in a miniature endoscopic form factor. Crossed electrode arrays address some of the key challenges surrounding probe fabrication for 3D ultrasound imaging by reducing the number of elements required (2N compared to N2). However, there remain practical challenges in packaging a high-frequency crossed electrode array into an endoscopic form factor. A process has been developed that uses a thinly diced strip of flex circuit to bring the back-side connections to common bond surface, which allows the final size of the endoscope to measure only 5 × 6 mm. A semi-kerfed, electrostrictive ceramic design was developed for the crossed electrode array. Hydrophone measurements were completed to confirm the pulse polarity and fast switching speed. Preliminary 3D images were generated of a wire phantom using the SAFE compounding technique.