Antifouling using ultrasonic vibrations with piezoceramic actuators.

Biofouling remains a persistent operational challenge for submerged marine infrastructure, particularly subsea instrumentation and control interfaces, where conventional antifouling coatings are ineffective over long service times. This study presents the development and validation of a piezoceramic-actuator-based, low-power ultrasonic antifouling system that inhibits organism attachment without relying on conventional cavitation effects. Six-actuator prototypes operating at 25 kHz were deployed for up to approximately 75 days in shallow marine waters in Galveston, Texas, USA. Continuous excitation at ±400 V peak-to-peak prevented settlement of macrofouling organisms including barnacles, but produced erosion bands on the prototype; numerical modelling confirmed that predicted surface vibration patterns corresponded to the observed bands. A second campaign in Goa, India, showed that intermittent excitation (3 min every 3 h) at ±120 V peak-to-peak achieved comparable antifouling performance while reducing energy consumption by approximately 300-fold relative to the continuous Galveston tests. Across three repeated tank experiments in Goa, algal surface coverage was reduced by 50-60% relative to untreated controls, remaining algae showed suppressed subsequent growth, and no erosion bands developed. These results indicate that low-power ultrasonic surface vibration offers an energy-efficient and environmentally compatible antifouling strategy suitable for long-term subsea applications.