Underwater Pressure Sensitive Paint Based on Nanoparticle Optical Properties

Triton proposes to solve the Navy's need for a sensor which can obtain skin pressure profiles on submerged objects of any shape without disturbing the flow profile around it. This will truly be a pressure-sensitive coating: different pressures will bedirectly observed as different colors. The color variation is due to the effects of interparticle distance on the optical properties of aggregates of closely spaced metal nanoparticles. The sensor will be a conformal coating which will ultimately bepainted on to the object, or else applied as a wrap-around polymer film. Triton's technology will allow the pressure measurement range to be engineered to user specifications, addressing 0-20 psi for this study. In addition to hydrostatic measurements,this system should be sensitive to kHz (or greater) dynamic pressure variations associated with acoustic vibration or turbulent flow. The surface pressure measurements made with Triton's film will be extremely useful in optimizing research and developmentefforts both for stress diagnostics (hydrostatic) and understanding the flow patterns that lead to unwanted noise (dynamic). Together with our industrial and academic collaborators, the Triton team will produce pressure-sensitive films in the Phase Iprogram, pursuing an aggressive path to rapid end-user application. The pressure sensor will be salable to R&D organizations since it will dramatically reduce the time and frequency of water channel measurements for test parts. We also intend to developthe material as an ultrasound sensor, and together with the determination of high stress zones that the coating can provide, we expect that it will find a use in the inspection and diagnostics field: (a) for laboratory diagnostics (stress diagnostics, anddetermination of k-w spectra), (b) field inspection of parts (as a rapid sensor for ultrasonic analysis), and (c) manufacturing inspection of parts for quality control.