Porous silicone substrates inhibit permanent barnacle attachment under natural conditions

Barnacles are able to effectively adhere to most surfaces underwater. Dewetting of the corresponding surface prior to the release of their permanent adhesive plays an important role in the attachment process. Possibly, a surface that is able to interfere with this process may have exceptional fouling repellence and fouling release abilities. Therefore, open-pored foams made from polydimethylsiloxane (PDMS) were tested together with flat PDMS samples as controls in a 13-week-long field experiment in the Baltic Sea. On a weekly basis, both settlement and fouling density development of the bay barnacle Balanus (=Amphibalanus) improvisus were monitored. The overall settlement was close to zero on PDMS foams and the few attached barnacles were not able to stay on the PDMS foams longer than 1 week after initial settlement. Changes in the stiffness of the PDMS foams did not affect these results. Open-pored PDMS foam systems may be a promising tool in the development of new, innovative antifouling strategies.