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Technical report | Assessing the use of Low Voltage UV-light Emitting Miniature LEDs for Marine Biofouling Control


The accumulation of biofouling on marine vessels and structures is an ongoing issue for managers and operators. For vessels, one particular design feature that has long posed a problem for biofouling control is seachests. Traditional marine antifouling solutions are typically in the form of underwater coatings. Studies have shown that antifouling paints in seachests are unable to perform as well as they do on uniform areas of the hull. A fundamentally different way of preventing biofouling is by using ultraviolet (UV) light emission. We present a new approach for biofouling prevention, in which a UV light emitting layer is applied on exposed underwater surfaces for the inhibition of settling organisms. The introduction of miniature UV light emitting diodes (LEDs) as a light source enables them to be embedded into thin, flexible, coating-like structures, in which the UV light diffuses uniformly within the surface. Optical design elements ensure the light escapes more or less uniformly all over the coating layer. In this report, we present a description of the technology and experimental setup, as well as the results of pilot investigations of the efficacy of UV LEDs for the prevention of marine biofouling in a simulated vessel seachest environment and compare this to theoretical simulations of the light intensity over the surface area.

Executive Summary

The accumulation of biofouling on marine vessels and structures results in reduced operational efficacy, increased running costs, and poses significant environmental risks through the transport of unwanted marine pest species. Seachests are one particular design feature of vessels that have long posed a problem for biofouling control. Seachests are difficult to access and inspect, and their diverse shape and size result in variable water flow regimes that are poorly suited to minimising biofouling settlement, and for the efficient performance of antifouling coatings.

Ultraviolet (UV) irradiation is a non-chemical alternative for biofouling control, able to kill and/or inhibit the growth of microscopic organisms, particularly when applied on a continuous basis. UV light has long been known to kill bacteria in bulk water circulation systems and is now a common method for water sterilization in the medical and food industries.

This report presents the outcomes from a pilot study evaluating a method of UV antifouling treatment with potential for use on vessel hulls and niche areas. The system uses miniature low power UV LEDs embedded within an optical-grade silicone matrix to create a UV light-emitting “skin” that can be fitted to submerged surfaces requiring protection. This method has the potential to overcome some of the existing issues with in-water UV antifouling treatments techniques (e.g. water clarity, exposure duration).

Modelling predicted that the effective anti-biofouling area of the UV footprint generated by each UV LED (out to a pre-determined minimum effective antifouling threshold of 1E-6 was 11.8 cm2, with a UV irradiance peak of 1.9E-4 Simulations also showed that the UV irradiance footprint (≥1E-6 extended perpendicular to the LED emitting surface to a distance of 3.0 cm, while the widest point of the antifouling footprint falling for each LED was 5.3 cm.

Experimental field-based trials were undertaken at the peak of the summer biofouling recruitment period to determine real-world efficacy of the system. Field trials used a nine UV LED array, with the units arranged in a 3 x 3 grid pattern fitted inside an experimental seachest unit. Overall, antifouling performance of the individual UV LEDs in the array was variable, with only four LEDs in the array maintaining a level of antifouling performance that was anticipated at the commencement of the study. A number of factors were identified to potentially explain the variable antifouling performance observed, including sub-optimal design of the array, circuitry failure and possible UV tolerance in some biofouling organisms. However, for the LEDs that did perform as expected, the surface area free of fouling around each of the LEDs ranged from 12.4 to 18.4 cm2, which was 5 – 56% larger than the effective UV footprint predicted from the LED modelling simulations. Similarly, the perpendicular distance from the LED emitting surface to the edge of the biofouling-free footprint and the widest point of the footprint all exceeded the predicted values from the simulation modelling (by 20 – 47% and 1.9 – 20.7%, respectively). These results suggest that the UV LEDs used in this study were emitting more power than was assumed in the simulation; or the effective UV antifouling threshold is in fact lower than the predicted value of 1E-6

This pilot study showed that UV LED technology can effectively prevent the accumulation of biofouling under high fouling pressure conditions. Subsequent trials that both refine the design of the LED array and more accurately quantify the UV irradiance signature and footprint of the LEDs will provide more definitive evidence of the techniques’ antifouling potential.

Recommendations for future studies and trials include:

  • Improved circuitry design, to ensure that each LED in the array receives a controlled and predetermined power input to enable maximum operational efficiency.
  • A more robust construction of the LED array, to minimize the chance of circuit breaks in the array that can result in intermittent LED operation.
  • Development of a robust technique to accurately quantify the UV output and “footprint” of each LED in the array, to correlate this with observed patterns of biofouling inhibition. This may be used to establish the actual antifouling threshold intensity (in required for effective treatment.
  • Effective and optimal spacing of the UV LEDs in the array, such that there is sufficient overlap in the individual UV LED footprints to ensure 100% prevention of biofouling accumulation.
  • Further investigation into the UV tolerance of different biofouling organisms and the effect of intermittent UV irradiance on biofouling development and inhibition.

Key information


Richard Piola; Bart Salters; Clare Grandison; Mark Ciacic and Roelant Hietbrink

Publication number


Publication type

Technical report

Publish Date

July 2016


Unclassified - public release


Biofouling; Ultra violet light; Seachest; Light emitting diodes