Octopus-inspired adhesive skins for intelligent and rapidly switchable underwater adhesion.
Ontology highlight
ABSTRACT:
SUBMITTER: Frey ST
PROVIDER: S-EPMC9278861 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The design of smart surfaces with switchable adhesive properties in a wet environment has remained a challenge in adhesion science and materials engineering. Despite intense demands in various industrial applications and exciting progress in mimicking the remarkable wet adhesion through the delicate control of catechol chemistry, polyelectrolyte complex, and supramolecular architectures, the full recapitulation of nature's dynamic function is limited. Here, we show a facile approach to synthesize bioinspired adhesive, which entails the reversible, tunable, and fast regulation of the wet adhesion on diverse surfaces. The smart wet adhesive takes advantage of the host-guest molecular interaction and the adhesive nature of catechol chemistry, as well as the responsive polymer, allowing for screening and activation of the interfacial interaction simply by a local temperature trigger in an on-demand manner. Our work opens up an avenue for the rational design of bioinspired adhesives with performances even beyond nature.
| S-EPMC5738439 | biostudies-literature
Project description:Can a robotic gripper only operate when attached to a robotic arm? The application space of the traditional gripper is limited by the robotic arm. Giving robot grippers the ability to move will expand their range of applications. Inspired by rich behavioral repertoire observed in octopus, we implement an integrated multifunctional soft robotic gripper with 6 independently controlled Arms. It can execute 8 different gripping actions for different objects, such as irregular rigid/soft objects, elongated objects with arbitrary orientation, and plane/curved objects with larger sizes than the grippers. Moreover, the soft gripper can realize omnidirectional crawling and swimming by itself. The soft gripper can perform highly integrated tasks of releasing, crawling, swimming, grasping, and retrieving objects in a confined underwater environment. Experimental results demonstrate that the integrated capabilities of multimodal adaptive grasping and omnidirectional motions enable dexterous manipulations that traditional robotic arms cannot achieve. The soft gripper may apply to highly integrated and labor-intensive tasks in unstructured underwater environments, including ocean litter collecting, capture fishery, and archeological exploration.
| S-EPMC11350063 | biostudies-literature
Project description:Water hampers the formation of strong and durable bonds between adhesive polymers and solid surfaces, in turn hindering the development of adhesives for biomedical and marine applications. Inspired by mussel adhesion, a mussel foot protein homologue (mfp3S-pep) is designed, whose primary sequence is designed to mimic the pI, polyampholyte, and hydrophobic characteristics of the native protein. Noticeably, native protein and synthetic peptide exhibit similar abilities to self-coacervate at given pH and ionic strength. 3,4-dihydroxy-l-phenylalanine (Dopa) proves necessary for irreversible peptide adsorption to both TiO2 (anatase) and hydroxyapatite (HAP) surfaces, as confirmed by quartz crystal microbalance measurements, with the coacervate showing superior adsorption. The adsorption of Dopa-containing peptides is investigated by attenuated total reflection infrared spectroscopy, revealing initially bidentate coordinative bonds on TiO2, followed by H-bonded and eventually long-ranged electrostatic and Van der Waals interactions. On HAP, mfp3s-pep-3Dopa adsorption occurs predominantly via H-bond and outer-sphere complexes of the catechol groups. Importantly, only the Dopa-bearing compounds are able to remove interfacial water from the target surfaces, with the coacervate achieving the highest water displacement arising from its superior wetting properties. These findings provide an impetus for developing coacervated Dopa-functionalized peptides/polymers adhesive formulations for a variety of applications on wet polar surfaces.
| S-EPMC5102340 | biostudies-literature
Project description:The soft organisms in nature have always been a source of inspiration for the design of soft arms and this paper draws inspiration from the octopus's tentacle, aiming at a soft robot for moving flexibly in three-dimensional space. In the paper, combined with the characteristics of an octopus's tentacle, a cable-driven soft arm is designed and fabricated, which can motion flexibly in three-dimensional space. Based on the TensorFlow framework, a data-driven model is established, and the data-driven model is trained using deep reinforcement learning strategy to realize posture control of a single soft arm. Finally, two trained soft arms are assembled into an octopus-inspired biped walking robot, which can go forward and turn around. Experimental analysis shows that the robot can achieve an average speed of 7.78 cm/s, and the maximum instantaneous speed can reach 12.8 cm/s.
| S-EPMC9065362 | biostudies-literature
Project description:Many gastropods release mucus hydrogels, which help them to remain attached to different substrates. Although not as strong as synthetic or biomimetic adhesives, some of these hydrogels have the ability to adhere to wet surfaces. These complex hydrogels mainly consist of proteins and carbohydrates, their natural cross-linking reactions being dependent on the presence of metals. In this paper, we investigated the role of metals in improving the underwater adhesive property of the mucus hydrogel from the slug Laevicaulis alte. We found that the strength and duration of attachment of two glass surfaces under water by the mucus hydrogel could be enhanced by its simple treatment with salts of metals, namely, Ca, Mg, Cu, or Zn. The degree of enhancement followed the order Ca2+ < Mg2+ < Zn2+ < Cu2+. The Cu2+-treated hydrogel kept two glass surfaces attached under water for about 20 days, while Zn2+ treatment caused attachment for about 15 days, as compared to the 3-5 days of attachment caused by the untreated gel. Treatment with both metals increased the underwater stability of the hydrogel almost threefold, presumably by strengthening its cross-linking. However, the Cu2+-treated hydrogel fell short of its adhesive function in the case of fast attachment within time scale of minutes, showing considerably low adhesive strength. From this study, we conclude that the treatment with Zn2+ is the best choice for improvement of the underwater adhesive property in terms of strength and stability. Overall, this work presents a novel biological underwater adhesive. The dynamic behavior of this multicomponent hydrogel in a versatile metal-rich environment may guide us toward designing new useful biomimetics.
| S-EPMC8223214 | biostudies-literature
Project description:Suction based attachment systems for pick and place handling of fragile objects like glass plates or optical lenses are energy-consuming and noisy and fail at reduced air pressure, which is essential, e.g., in chemical and physical vapor deposition processes. Recently, an alternative approach toward reversible adhesion of sensitive objects based on bioinspired dry adhesive structures has emerged. There, the switching in adhesion is achieved by a reversible buckling of adhesive pillar structures. In this study, we demonstrate that these adhesives are capable of switching adhesion not only in ambient air conditions but also in vacuum. Our bioinspired patterned adhesive with an area of 1 cm(2) provided an adhesion force of 2.6 N ± 0.2 N in air, which was reduced to 1.9 N ± 0.2 N if measured in vacuum. Detachment was induced by buckling of the structures due to a high compressive preload and occurred, independent of air pressure, at approximately 0.9 N ± 0.1 N. The switch in adhesion was observed at a compressive preload between 5.6 and 6.0 N and was independent of air pressure. The difference between maximum adhesion force and adhesion force after buckling gives a reasonable window of operation for pick and place processes. High reversibility of the switching behavior is shown over 50 cycles in air and in vacuum, making the bioinspired switchable adhesive applicable for handling operations of fragile objects.
| S-EPMC4642880 | biostudies-other
Project description:A soft gripper inspired by the glowing sucker octopus (Stauroteuthis syrtensis)' highly evolved grasping capability enabled by the umbrella-shaped dorsal and ventral membrane between each arm is presented here, comprising of a 3D-printed linkage mechanism used to actuate a modular mold silicone-casting soft suction disc to deform. The soft gripper grasp can lift objects using the suction generated by the pump in the soft disc. Moreover, the protruded funnel-shaped end of the deformed suctorial mouth can adapt to smooth and rough surfaces. Furthermore, when the gripper contacts the submerged target objects in a turbid environment, local suctorial mouth arrays on the suction disc are locked, causing the variable flow inside them, which can be detected as a tactile perception signal to the target objects instead of visual perception. Aided by the 3D-printed linkage mechanism, the soft gripper can grasp objects of different shapes and dimensions, including flat objects, objects beyond the grasping range, irregular objects, scattered objects, and a moving turtle. The results report the soft gripper's versatility and demonstrate the vast application potentials of self-adaptive grasping and sensing in various environments, including but are not limited to underwater, which is always a key challenge of grasping technology.
| S-EPMC9189663 | biostudies-literature
Project description:Many insects can climb smooth surfaces using hairy adhesive pads on their legs, mediated by tarsal fluid secretions. It was previously shown that a terrestrial beetle can even adhere and walk underwater. The naturally hydrophobic hairs trap an air bubble around the pads, allowing the hairs to make contact with the substrate as in air. However, it remained unclear to what extent such an air bubble is necessary for underwater adhesion. To investigate the role of the bubble, we measured the adhesive forces in individual legs of live but constrained ladybird beetles underwater in the presence and absence of a trapped bubble and compared these with its adhesion in air. Our experiments revealed that on a hydrophobic substrate, even without a bubble, the pads show adhesion comparable to that in air. On a hydrophilic substrate, underwater adhesion is significantly reduced, with or without a trapped bubble. We modelled the adhesion of a hairy pad using capillary forces. Coherent with our experiments, the model demonstrates that the wetting properties of the tarsal fluid alone can determine the ladybird beetles' adhesion to smooth surfaces in both air and underwater conditions and that an air bubble is not a prerequisite for their underwater adhesion. This study highlights how such a mediating fluid can serve as a potential strategy to achieve underwater adhesion via capillary forces, which could inspire artificial adhesives for underwater applications.
| S-EPMC8545753 | biostudies-literature
Project description:Many insect species reversibly adhere to surfaces by combining contact splitting (contact formation via fibrillar contact elements) and wet adhesion (supply of liquid secretion via pores in the insects' feet). Here, we fabricate insect-inspired fibrillar pads for wet adhesion containing continuous pore systems through which liquid is supplied to the contact interfaces. Synergistic interaction of capillarity and humidity-induced pad softening increases the pull-off force and the work of adhesion by two orders of magnitude. This increase and the independence of pull-off force on the applied load are caused by the capillarity-supported formation of solid-solid contact between pad and the surface. Solid-solid contact dominates adhesion at high humidity and capillarity at low humidity. At low humidity, the work of adhesion strongly depends on the amount of liquid deposited on the surface and, therefore, on contact duration. These results may pave the way for the design of insect-inspired adhesive pads.
| S-EPMC4383020 | biostudies-literature
Project description:In medical robotics, micromanipulation becomes particularly challenging in the presence of blood and secretions. Nature offers many examples of adhesion strategies, which can be divided into two macro-categories: morphological adjustments and chemical adaptations. This paper analyzes how two successful specializations from different marine animals can converge into a single biomedical device usable in moist environments. Taking inspiration from the morphology of the octopus sucker and the chemistry of mussel secretions, we developed a protein-coated octopus-inspired micro-sucker device that retains in moist conditions about half of the adhesion it shows in dry environments. From a robotic perspective, this study emphasizes the advantages of taking inspiration from specialized natural solutions to optimize standard robotic designs.
| S-EPMC7511962 | biostudies-literature