3D volumetric imaging system based on a carbon-based light-induced ultrasound transmitter

We present a 3-D ultrasound imaging system utilizing a light-based ultrasound transmitter. The system achieves high spatial resolution through a plain surface coated with a thin layer of carbon nanotubes (CNTs), which is optically scanned by a pulsed laser. The transmitter is fabricated by depositing a CNT-polydimethylsiloxane composite onto a glass substrate using techniques such as dip coating, dropping, and spin coating. The transmission characteristics are dependent on the laser beam width and CNT layer thickness, with the spin-coated layer demonstrating a center frequency of 9.08 MHz and bandwidth of 12.65 MHz. The imaging system boasts an axial resolution of 200 μm and lateral resolution of 190 μm. 3-D imaging was successfully performed on a chicken heart with a penetration depth up to 30 mm, providing a potential replacement for complex high voltage pulser circuits with a simple and manufacturable optical ultrasound transmitter.