Microfluidic simulation of a colonial diatom chain reveals oscillatory movement

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. Acomputational 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

Приклади завдань для позакласної роботи з інформатики у початковій школі

У статті коротко описана методика проведення позакласної роботи з інформатики у початковій школі

Microfluidic simulation of a colonial diatom chain reveals oscillatory movement

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. Acomputational 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

Exploring the innovational potential of biomimetics for novel 3D MEMS.

Abstract A novel way to describe the complexity of biological and engineering approaches depending on the number of different base materials is proposed: Either many materials are used (material dominates) or few materials (form dominates) or just one material (structure dominates). The complexity of the approach (in biology as well as in engineering) increases with decreasing number of base materials. Biomimetics, i.e., technology transfer from biology to engineering, is especially promising in MEMS development because of the material constraints in both fields. The Biomimicry Innovation Method is applied here for the first time to identify naturally nanostructured rigid functional materials, and subsequently analyze their prospect in terms of inspiring MEMS development

Dielectrophoresis-based microfluidic platforms for cancer diagnostics

The recent advancement of dielectrophoresis (DEP)-enabled microfluidic platforms is opening new opportunities for potential use in cancer disease diagnostics. DEP is advantageous because of its specificity, low cost, small sample volume requirement, and tuneable property for microfluidic platforms. These intrinsic advantages have made it especially suitable for developing microfluidic cancer diagnostic platforms. This review focuses on a comprehensive analysis of the recent developments of DEP enabled microfluidic platforms sorted according to the target cancer cell. Each study is critically analyzed, and the features of each platform, the performance, added functionality for clinical use, and the types of samples, used are discussed. We address the novelty of the techniques, strategies, and design configuration used in improving on existing technologies or previous studies. A summary of comparing the developmental extent of each study is made, and we conclude with a treatment of future trends and a brief summary