Development, Optimization, Biological Assays, and In Situ Field Immersion of a Transparent Piezoelectric Vibrating System for Antifouling Applications

Abstract

This paper presents the development and experimentations of transparent vibrating piezoelectric micromembranes dedicated to protecting immersed measurement instruments from marine biofouling. As any surface immersed is subject to the adhesion and settlement of organisms, especially in seawater, transparent materials quickly become opaque, resulting in deteriorated accuracy for optical sensors. According to this, we developed a transparent vibrating membrane to promote biofouling detachment in order to reduce the data quality drift and the frequency of maintenance operations on deployed optical sensors. In the first part, the design, the materials, and the steps to manufacture demonstrators are described. Then, the electromechanical characteriza-tions of the demonstrators are carried out and interpreted with the support of FEM simulations. The last part describes the laboratory bioassays and the field immersion tests. Laboratory bioassays assess the antifouling potential of the vibrating piezoelectric membranes by exposing their surface to a suspended bacterial solution. In situ assays allow the membrane to perform in the Mediterranean Sea to assess their effectiveness in real conditions. Laboratory bioassays showed a great potential against the adhesion and settlement of a bacterial solution, while in situ tests confirmed the anti-fouling effect of piezoelectric vibrating micromembrane. Nevertheless, in situ experimentations re-vealed troubles with the piezo driver actuating the vibrating membranes, and tests should be carried out again with an improved piezo driver to reveal the full potential of the vibrating membranes. These are the first steps to set up an efficient antifouling vibrating system for immersed optical sensors.