Collector and Dosing-Device Architectures in Electrospinning: A Classification by Product Dimensionality and Its Implications for Scale-Up

Abstract

The electrospinning process is physically identical in all installations, yet the products obtained from them differ radically in architecture, and the difference is determined almost entirely by the configuration of the electrodes and the dosing device rather than by the process parameters. This review classifies the reported collector and emitter architectures by the dimensionality of the product they yield — one-dimensional bundles and yarns, two-dimensional sheets and webs, and three-dimensional tubular and shaped constructs — and relates each architecture to the four intrinsic limitations of electrospinning: the polymodal distribution of fibre diameters, the occurrence of morphological defects, the disordered orientation of the deposited fibres, and the small number of capillaries that can be operated simultaneously. It is shown that the first two limitations are addressable only through the solution and the process regime, whereas the third and fourth are addressable only through hardware, so that collector and emitter design and formulation development are complementary rather than alternative routes to improvement. A modern laboratory installation is analysed as a case study, and its configuration options are mapped onto the classification. The throughput limitation is then examined quantitatively: for a single-emitter laboratory system, the areal deposition rate implies an output that is two to three orders of magnitude below industrial requirements, and the multiplication factors available from multi-capillary, coaxial and free-surface emitters are compared.