Biomimetic tag attachment inspired by the seal louse

Satellite telemetry is widely used to study the movements of marine mammals, but current attachment methods for seals typically rely on epoxy adhesives, which pose risks to animal welfare and the marine environment. This study presents a biomimetic, adhesive-free attachment system inspired by the seal louse<i>Echinophthirius horridus</i>, an ectoparasite capable of maintaining a strong grip on seal fur in aquatic conditions. A top-down biomimetic approach was used to abstract key functional principles from the louse's claw morphology and cuticular anchoring structures. These biological features informed the development of a 3D-printed comb-clamp prototype, termed 'TACS' (Transmitter Attachment Clamp[s]), designed specifically for the hair structure of harbour seals. Microscopy and x-ray microtomography revealed morphological traits such as interlocking setae, directional grooves, and a specialised euplantula, which were functionally integrated into the prototype. Tensile tests on tanned seal fur demonstrated mean maximum retention forces of 4.58 N under dry conditions and 2.42 N under wet conditions. A proof-of-concept trial on a live harbour seal showed successful attachment for up to 50 min, without signs of distress or fur damage. The TACS system fulfilled key design criteria: rapid and reversible application, low material weight (<20 g), and strong mechanical retention without the use of adhesives. This study demonstrates the potential of biologically inspired design to provide an environmentally responsible alternative to conventional tagging methods and highlights the relevance of<i>E. horridus</i>as a functional model for bioinspired gripping systems in marine applications.