Synthesis and Characterization of a Biocompatible, Polymer Matrix Nanocomposite for Photoacoustic Applications

Polymer matrix nanocomposites hold promise for being used as biocompatible, photoacoustic emitting materials. Such a combination of material capabilities has potential in the application of minimally invasive epiretinal implants that can be used to deliver a vision-like experience to patients with macular degenerative vision loss. A method based on chemical vapor deposition is used for in situ growth of palladium nanoparticles in a polydimethylsiloxane matrix. This scalable method is shown to prevent nanoparticle agglomeration that is typically seen with other commonly used nanocomposite synthesis methods. This method can be iterated multiple times on the same sample to increase nanoparticle diameters. In this work, we report characterization results on samples created with this process obtained using UV-Vis-NIR spectrometry, x-ray diffraction (XRD), and transmission electron microscopy (TEM). Results are also reported for the photoacoustic response of these materials obtained using a pulsed laser ultrasonic transmitter and a hydrophone receiver. These results will assist in the design of epiretinal implants that can be used as part of a prosthetic system to provide a vision-like experience for users.