Three-dimensional imaging of electrospun fiber mats using confocal laser scanning microscopy and digital image analysis

Abstract

Confocal laser scanning microscopy with fluorescent markers and index matching has been used to collect three-dimensional (3D) digitized images of electrospun fiber mats and of a borosilicate glass fiber material. By embedding the fluorescent dye in either the material component (fibers) or pore space component (the index matching fluid), acquisitions of both positive and negative images of the porous fibrous materials are demonstrated. Image analysis techniques are then applied to the 3D reconstructions of the fibrous materials to extract important morphological characteristics such as porosity, specific surface area, distributions of fiber diameter and of pore diameter, and fiber orientation distribution; the results are compared with other experimental measurements where available. The topology of the pore space is quantified for an electrospun mat for the first time using the Euler-Poincaré characteristic. Finally, a method is presented for subdividing the pore space into a network of cavities and the gates that interconnect them, by which the network structure of the pore space in these electrospun mats is determined.

Topological and network analysis of lithium ion battery components: the importance of pore space connectivity for cell operation

“…Finally, lithium ion battery separators are just one example of a component in energy and environmental systems that can benefit from the topological and network analysis presented here. 42,43 Connectivity can also improve understanding and design of separators in other electrochemical systems such as fuel cells 44,45 or ion-selective membranes for desalination, 46,47 providing insights such as how thick a membrane should be or how transport paths can be designed to prevent mixing of product/reactant streams. Furthermore, beyond separator technology, we propose that all electrochemical systems (catalysis stacks for fuel generation, sensitised solar cells, lithium ion battery anodes and cathodes, etc.)…”

Solution blow spinning fibres: New immunologically inert substrates for the analysis of cell adhesion and motility

“…It is important to note that, due to random fibre deposition on the collector, spaces within fibre mats will not be in the same range for each fibre preparation of a given SBS type. Hence, care should be taken when interpreting these data as suggested also by the controversy regarding methodologies, variance and meaning of fibre mat porosity [10,29,30].…”

GPU-accelerated ray-casting for 3D fiber orientation analysis

“…A similar approach was suggested for investigation of scaffold organization of the engineered heart valve tissue for post- and pre-implants [ 33 ]. For the quantification of electrospun fiber mats organization, a tensor calculation at every voxel of segmented fibers with maintaining a neighborhood radius larger than maximal fiber diameter was proposed in [ 34 ]. Another approach measures orientation of fibers in planar sections of reinforced composite materials by detecting elliptical and non-elliptical footprints to derive a 3D structure tensor [ 35 – 38 ].…”