Fluid mechanics and rheology of the jumping spider body fluid. Issue 22 (11th May 2021)

• Record Type: Journal Article
• Authors: Göttler, Chantal; Amador, Guillermo; van de Kamp, Thomas; Zuber, Marcus; Böhler, Lisa; Siegwart, Roland; Sitti, Metin
• Is Part Of: Soft matter. Volume 17:Issue 22(2021)
• Page Start: 5532
• Page End: 5539
• Publication Date: 2021-05-11
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/d1sm00338k
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : We studied the flow and physical properties of the hydraulic body fluid of spiders. Our results suggest that this fluid, which drives leg extension, is shear-thinning. This interesting characteristic could inspire hydraulic systems for soft-robotics. Abstract : Spiders use their inner body fluid ("blood" or hemolymph) to drive hydraulic extension of their legs. In hydraulic systems, performance is highly dependent on the working fluid, which needs to be chosen according to the required operating speed and pressure. Here, we provide new insights into the fluid mechanics of spider locomotion. We present the three-dimensional structure of one of the crucial joints in spider hydraulic actuation, elucidate the fluid flow inside the spider leg, and quantify the rheological properties of hemolymph under physiological conditions. We observe that hemolymph behaves as a shear-thinning non-Newtonian fluid with a fluid behavior index n = 0.5, unlike water ( n = 1.0).