Figure 3
From: Towards uniformly oriented diatom frustule monolayers: Experimental and theoretical analyses
C. sp. diatom frustules following sulfuric acid cleaning and monolayer assembly. (a) A frustule with its concave side facing upwards (lower left) and a frustule with its concave side facing downwards (upper right). (b) Side view of a single C. sp. diatom frustule. (c) Cross-section of a C. sp. frustule: labels 1–4 indicate different porous layers from the concave side to the convex side of a frustule, where 1 shows a partial foramen pore, 2 shows an areola chamber wall, 3 shows a cribrum pore, and 4 shows the cribellum pores. (d) Diatom monolayer without bubble-induced agitation: ~60% of the diatoms were in a ‘concave-down’ orientation. (e) Nearly 90% of the diatoms were successfully adjusted to a ‘concave-down’ orientation on a substrate after bubble-induced agitation.
