### Abstract

Diatoms are single-celled organisms with rigid parts in relative motion at the micro-and nanometer length scales. Some diatom species form colonies comprising many cells. In this manuscript, the results of a two-dimensional finite element computer model are presented. This model was established to discover if diatom colonies start to exhibit some kind of »pumping« behaviour when subjected to water flow. To analyze this computationally, a model diatom colony with continuously repeated units of ten cells is investigated in a fluid dynamic simulation. In this first simple model, undisturbed fluid flow is allowed for between the single cells. The cells do not move actively, and are solely moved by the water. The initial fluid velocity is assumed between 0.01 m s^{-1} and 1 m s^{-1}. A computational result that does not change anymore with time is called a steady state solution. Such a steady state solution is reached in all calculations performed. The steady state for a chain where initially all diatoms are spaced equally (equidistant spacing) has forces that encourage the formation of cell pairs with less distance between one another. These forces result from the flow of the surrounding fluid. The steady state for a chain with initially paired cells shows the opposite effect: the pairs tend to un-pair and head for the equidistant state again. The mutual change in forces between these two states, i.e., paired and unpaired formations, suggests that these two steady states lead into each other: The computer simulations suggest that a diatom colony subjected to water flow exhibits some kind of oscillatory movement. Such movement might facilitate nutrient uptake of the diatom colony.

Original language | English |
---|---|

Pages (from-to) | 431-441 |

Number of pages | 11 |

Journal | Acta Botanica Croatica |

Volume | 68 |

Issue number | 2 |

Publication status | Published - Oct 2009 |

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### Keywords

- Computer simulation
- Diatom chain
- Fluid dynamics
- Hydroelastics
- Nutrient uptake

### ASJC Scopus subject areas

- Plant Science
- Ecology, Evolution, Behavior and Systematics

### Cite this

*Acta Botanica Croatica*,

*68*(2), 431-441.

**Microfluidic simulation of a colonial diatom chain reveals oscillatory movement.** / Srajer, Johannes; Yeop Majlis, Burhanuddin; Gebeshuber, Ille C.

Research output: Contribution to journal › Article

*Acta Botanica Croatica*, vol. 68, no. 2, pp. 431-441.

}

TY - JOUR

T1 - Microfluidic simulation of a colonial diatom chain reveals oscillatory movement

AU - Srajer, Johannes

AU - Yeop Majlis, Burhanuddin

AU - Gebeshuber, Ille C.

PY - 2009/10

Y1 - 2009/10

N2 - Diatoms are single-celled organisms with rigid parts in relative motion at the micro-and nanometer length scales. Some diatom species form colonies comprising many cells. In this manuscript, the results of a two-dimensional finite element computer model are presented. This model was established to discover if diatom colonies start to exhibit some kind of »pumping« behaviour when subjected to water flow. To analyze this computationally, a model diatom colony with continuously repeated units of ten cells is investigated in a fluid dynamic simulation. In this first simple model, undisturbed fluid flow is allowed for between the single cells. The cells do not move actively, and are solely moved by the water. The initial fluid velocity is assumed between 0.01 m s-1 and 1 m s-1. A computational result that does not change anymore with time is called a steady state solution. Such a steady state solution is reached in all calculations performed. The steady state for a chain where initially all diatoms are spaced equally (equidistant spacing) has forces that encourage the formation of cell pairs with less distance between one another. These forces result from the flow of the surrounding fluid. The steady state for a chain with initially paired cells shows the opposite effect: the pairs tend to un-pair and head for the equidistant state again. The mutual change in forces between these two states, i.e., paired and unpaired formations, suggests that these two steady states lead into each other: The computer simulations suggest that a diatom colony subjected to water flow exhibits some kind of oscillatory movement. Such movement might facilitate nutrient uptake of the diatom colony.

AB - Diatoms are single-celled organisms with rigid parts in relative motion at the micro-and nanometer length scales. Some diatom species form colonies comprising many cells. In this manuscript, the results of a two-dimensional finite element computer model are presented. This model was established to discover if diatom colonies start to exhibit some kind of »pumping« behaviour when subjected to water flow. To analyze this computationally, a model diatom colony with continuously repeated units of ten cells is investigated in a fluid dynamic simulation. In this first simple model, undisturbed fluid flow is allowed for between the single cells. The cells do not move actively, and are solely moved by the water. The initial fluid velocity is assumed between 0.01 m s-1 and 1 m s-1. A computational result that does not change anymore with time is called a steady state solution. Such a steady state solution is reached in all calculations performed. The steady state for a chain where initially all diatoms are spaced equally (equidistant spacing) has forces that encourage the formation of cell pairs with less distance between one another. These forces result from the flow of the surrounding fluid. The steady state for a chain with initially paired cells shows the opposite effect: the pairs tend to un-pair and head for the equidistant state again. The mutual change in forces between these two states, i.e., paired and unpaired formations, suggests that these two steady states lead into each other: The computer simulations suggest that a diatom colony subjected to water flow exhibits some kind of oscillatory movement. Such movement might facilitate nutrient uptake of the diatom colony.

KW - Computer simulation

KW - Diatom chain

KW - Fluid dynamics

KW - Hydroelastics

KW - Nutrient uptake

UR - http://www.scopus.com/inward/record.url?scp=70549089819&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70549089819&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:70549089819

VL - 68

SP - 431

EP - 441

JO - Acta Botanica Croatica

JF - Acta Botanica Croatica

SN - 0365-0588

IS - 2

ER -