碩士 / 國立中興大學 / 生物物理學研究所 / 106 / Attachment plays an important role in living of creatures. Many aquatic animals use suckers for attachment during maintaining position, movement, or predation. Both octopus and cuttlefish are cephalopods using suckers for attachment, but their suckers are different in structure, functioning mechanism, predation behavior, and prey type. Unlike octopus, cuttlefish reach the prey by fast striking of two tentacles and capture it with suckers on the clubs. The cuttlefish suckers do not require muscle contraction to function, therefore are believed to work by passive mechanism. The muscular stalk, suction cup wall, and sucker ring have been proposed for transmitting force, sealing with the substrate, and maintaining contact shape, which are the three major components of suction. Although the functioning mechanism of suckers has been studied, but the attachment-detachment processes and the cause of detaching have never been examined. To this end, I measured the suction force and deformation of tentacular suckers in cuttlefish Sepia pharaonis, and synchronously filmed the shape change of the contact interface. Comparison of the suction force, pressure difference, and compressibility reveals that the bubbles appeared within the suckers obviously changed the force-deformation curve during the attachment-detachment process. Because gas deforms more easily than the liquid, the expansion of the bubbles would retard the increase of pressure difference. Furthermore, I found that the suction force of suckers would not be affected by the substrate roughness and insertion of a PVC ring. My results suggest that the causes of detachment might not be damage of the sucker structure or breakdown of water cohesion, but failure of sealing due to deformation of sucker muscles. When the extension reaches its limit, the suckers would unseal and detach from the substrate. Such mechanical features of tentacular suckers fit cuttlefish’s predation strategy in capturing fast-moving preys. Although similar structures are common in artificial suckers, cuttlefish suckers perform well on rough, curved, or even soft surfaces, which provide insights for future bio-inspired design of underwater attachment devices.
| Identifer | oai:union.ndltd.org:TW/106NCHU5109001 |
| Date | January 2018 |
| Creators | Tien-Yun Lin, 林殿昀 |
| Contributors | Kai-Jung Chi, 紀凱容 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 36 |
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