[Zurück]

J. Srajer, I. Gebeshuber:
"Microfluidic simulation of a colonial diatom chain reveals pumping behavior";
Vortrag: 20th Intern. Diatom Symp. 2008, Dubrovnik/Croatia; 08.09.2008; in: "Abstract Book 20th Intern. Diatom Symp. 2008", (2008), S. 88.

Rutilaria philippinarum is a fossil colonial sea-water diatom that used to live in shallow waters [1]. Inspired by recent studies on the linking structures that connect sibling cells [2] a microfluidic computer model was created. This two-dimensional finite element model has the following assumptions: the cell size is 140 micrometers * 34 micrometers, the distance between cells varies from 10 micrometers to 30 micrometers, there are 10 cells with periodic boundary conditions. Undisturbed fluid flow between the single cells is allowed for in this first simple model. The cells do not move actively, and are solely moved by the water. The initial fluid velocity varies between 0.01m/s and 1m/s. Stationary solutions of the model starting from equidistant cells shows pairing of neighboring cells. On the other hand, starting the calculations from already paired cells shows the opposite effect: the pairs aspire the equidistant state again. From this result it is concluded that the alternation between these two stationary states causes an oscillatory movement of the chain. It still has to be shown if this effect also appears in a chain of living diatoms with the silica frustules covered with organic material. If it does, this "pumping behavior" might facilitate nutrient uptake. In any case, our modeling attempts might have laid a bio-inspired basis for a novel type of pumps in the micrometer length scale [3,4]. The appearance of such vibrations in fan wings is a similar effect on the meter length scale.
References:
[1] Ross, R. (1995) "A revision of Rutilaria Greville (Bacillariophyta)", Bulletin Natural History Museum, Botany series 25: 1-93.
[2] Gebeshuber I.C. and Crawford R.M. (2006) "Micromechanics in biogenic hydrated silica: hinges and interlocking devices in diatoms", Proc. IMechE Part J: J. Eng. Tribol. 220(J8), 787-796.
[3] Gebeshuber I.C. (2007) "Biotribology inspires new technologies", invited article, Nano Today 2(5), 30-37.
[4] Gebeshuber I.C. and Drack M. (2008) invited article, "An attempt to reveal synergies between biology and engineering mechanics", IMechE Part C: J. Mech. Eng. Sci. 222, 1281-1287. \