Berlin 2018 – scientific programme

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BP: Fachverband Biologische Physik

BP 11: Bioimaging and Biopspectroscopy I

BP 11.2: Talk

Tuesday, March 13, 2018, 10:00–10:15, H 1028

Microstructural analysis of the walls of termite nests using X-ray micro-tomography — •Kamaljit Singh¹, Bagus P. Muljadi², Ali Q. Raeini¹, Veerle Vandeginste², Martin J. Blunt¹, Christian Jost³, Guy Theraulaz³, and Pierre Degond¹ — ¹Imperial College London, UK — ²The University of Nottingham, UK — ³Centre de Recherches sur la Cognition Animale, CNRS, Toulouse, France

Termite nests have long been investigated for thermoregulation and ventilation by self-sustaining CO2 exchange to the outer atmosphere. Although the outer walls of termite nests are believed to be porous, and have been hypothesized as a source of gas exchange, the morphological features of the walls, and their role in controlling ventilation and heat conduction are unknown. We have investigated the microstructure of the outer and inner walls of the Trinervitermes geminatus termite nests (from Senegal and Guinea) in three dimensions using high-resolution X-ray micro-tomography. In the Senegal nest, we observe inter-connected network of larger and smaller pores. By contrast, the walls of the Guinea nest contain only the inter-connected larger pores. The smaller pores do not form, due to larger fraction of clay in the nest. From the 3D flow field simulations, we show that the presence of larger inter-connected pores in both nest materials enhances the permeability and CO2 diffusion across the outer walls. Moreover, the network of larger pores help in draining the water from the nest walls after rainy periods, therefore, re-establishing the ventilation of the nest as well as providing structural stability to the nest.