Innovative UV Biofouling Mitigation Technique for In-water Optical Sensors

This project will build upon research conducted during a Phase I SBIR effort, which showed that germicidal UV-C radiation emitted by LEDs installed inside of submerged radiometers can reach levels known to prevent biofouling (accumulation of biological matter) on their external optical surfaces (windows, diffusers) without affecting the instrument’s measurements. This technology will improve the long-term accuracy of sensors monitoring the health of the oceans and their data products (e.g., concentration of chlorophyll and dissolved organics). We will build and test multichannel and single-channel radiometers for measuring light (irradiance and radiance) in the ultraviolet, visible, and infrared range. Challenges include the integration of LEDs and other optical elements identified in Phase I into pressure-rated underwater housings that can withstand deployment in the ocean for several months or more without the need of servicing. Once designed and prototyped, these radiometers will be rigorously tested in San Diego Bay and in a tidal estuarine river with extremely high biofouling rates. At the end of this project, we anticipate that these radiometers will be ready for sale. We will also re-evaluate published thresholds for the prevention of biofouling and will determine whether the onset of biofouling can be detected in the radiometers’ measurements.