Please use this identifier to cite or link to this item: http://doi.org/10.25358/openscience-9300
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dc.contributor.authorSudersan, Pranav-
dc.date.accessioned2023-08-01T12:39:08Z-
dc.date.available2023-08-01T12:39:08Z-
dc.date.issued2023-
dc.identifier.urihttps://openscience.ub.uni-mainz.de/handle/20.500.12030/9318-
dc.description.abstractMany animals are known to possess the remarkable ability to stick, walk or climb on any surface. While some of the bigger animals such as monkeys or cats use their limbs or claws to mechanically grip to available protrusions on a vertical surface to climb up, some smaller animals, such as lizards and insects, can also climb on smooth surfaces where such a gripping mechanism should not be possible. On closer inspection, one would find that these animals possess specialised organs at the bottom of their feet, known as adhesive pads. The adhesive pads have naturally evolved into various forms depending on the animal: some have a dense array of hair-like structures, some are smooth and flexible, while some also secrete an adhesive fluid at the bottom. A curious property of these pads, which is not fully understood, is their ability to control adhesion instantly and achieve fast attachment and detachment as per necessity. Some animals such as ladybugs and geckos, which possess ‘hairy’ pads, can also surprisingly walk on underwater surfaces. Underwater adhesion is usually difficult to achieve due to the presence of interfacial water and thus, it is not entirely clear how these animals are able to accomplish this. In the present work, I attempt to resolve these mysteries by using a combination of experiments on live insects and numerical simulations. I show that, the surface tension forces due to the foot's secretions is the the primary driver of the ladybug beetle's adhesion to surfaces. Here, the balance of the different interfacial energies made by the secretion fluid with the surrounding medium is found to create the right wetting conditions for the fluid to show strong capillary forces, even when the insect's foot is submerged underwater. In order to characterise these secretions, which are of femtolitre scale volume, I develop a general method to perform surface tension measurements on microscopic liquid droplets with the help of Atomic Force Microscopy. I further show, based on a simple theoretical model, that a ‘hairy’ pad design of the insect's foot is not only useful to improve contact with most surfaces, but can also help control its adhesion by simply tilting the foot relative to the surface. My findings here highlight some new strategies through which underwater adhesion can be achieved and controlled, which could potentially inspire the design of artificial reversible adhesives.en_GB
dc.language.isoengde
dc.rightsCC BY*
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/*
dc.subject.ddc530 Physikde_DE
dc.subject.ddc530 Physicsen_GB
dc.subject.ddc540 Chemiede_DE
dc.subject.ddc540 Chemistry and allied sciencesen_GB
dc.subject.ddc570 Biowissenschaftende_DE
dc.subject.ddc570 Life sciencesen_GB
dc.subject.ddc590 Tiere (Zoologie)de_DE
dc.subject.ddc590 Zoological sciencesen_GB
dc.subject.ddc600 Technikde_DE
dc.subject.ddc600 Technology (Applied sciences)en_GB
dc.subject.ddc620 Ingenieurwissenschaften und Maschinenbaude_DE
dc.subject.ddc620 Engineering and allied operationsen_GB
dc.titleMechanisms of reversible underwater adhesion in ladybug beetlesen_GB
dc.typeDissertationde
dc.identifier.urnurn:nbn:de:hebis:77-openscience-0237b91f-13a9-4824-b071-fdae3188a41e7-
dc.identifier.doihttp://doi.org/10.25358/openscience-9300-
jgu.type.dinitypedoctoralThesisen_GB
jgu.type.versionOriginal workde
jgu.type.resourceTextde
jgu.date.accepted2023-07-17-
jgu.description.extentix, 181 Seiten ; Illustrationen, Diagrammede
jgu.organisation.departmentMaxPlanck GraduateCenterde
jgu.organisation.number9010-
jgu.organisation.nameJohannes Gutenberg-Universität Mainz-
jgu.rights.accessrightsopenAccess-
jgu.organisation.placeMainz-
jgu.subject.ddccode530de
jgu.subject.ddccode540de
jgu.subject.ddccode570de
jgu.subject.ddccode590de
jgu.subject.ddccode600de
jgu.subject.ddccode620de
jgu.organisation.rorhttps://ror.org/023b0x485-
Appears in collections:JGU-Publikationen

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