A comprehensive electric field analysis of a multifunctional electrospinning platform Erol Jentzsch a, * , Ömer Gül b , Ertan Öznergiz c a Electrical & Electronics Faculty, Istanbul Technical University, Turkey b Istanbul Technical University, Turkey c Yildiz Technical University, Turkey article info Article history: Received 30 August 2012 Accepted 4 December 2012 Available online 4 February 2013 Keywords: Electrospinning Electric field analysis Multifunctional electrospinning platform abstract The electric field is one of the most critical parameters in electrospinning process. This study provides a comprehensive electric field analysis of a multifunctional electrospinning platform performed by FEMM 4.2. In this paper firstly information about the electrospinning method is mentioned. Electric field distribution of the multifunctional electrospinning platform is analyzed in different voltage levels. The effect of the applied voltage between the needles and the collector on nanofibers is investigated which are collected on the chassis. Furthermore the analysis results clearly demonstrated the effect of elec- trostatic force on the multiple jets which are at the needle tips. Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction Electrospinning is the most effective, cheap and simple method of producing polymer-based nanofibers [1e4]. Additionally elec- trospinning is a multi-disciplinary method which contains fluid dynamics, polymer chemistry, basic physics, electric physics, me- chanical and textile engineering [5]. Electric field is one of the most crucial parameters in electro- spinning process. Moreover it can be controlled by changing volt- age, distance between the needle and the collector, type of the collector and the characteristics of the needle [6]. These parameters change the fiber morphology considerably. Taylor obtained that a minimum voltage of 6 kV, either positive or negative, is enough for the solution at the needle tip to turn into a Taylor Cone throughout jet initiation [7]. Higher voltages result in a more charge. Thus, this will accelerate the jet and a greater amount of solution will come out from the needle tip [8]. Changing the dis- tance between the needle and the target will directly affect the flight time and electric field strength [8]. Mo et al. found that a less internal diameter of a needle lowers occlusion of needles as well as beads on the nanofibers [9]. Depending on the application the type of the collector varies. There are several ways of calculating the electric field distri- bution. Ying Yang et al. [10] and Cuiru Yang et al. [11] for example used ANSOFT software to calculate electric field distribution in the xz plane. Carnell et al. [12] created an experimental set-up, cal- culated equipotential lines for different electrode spacings with a formula and noted that at every location electric field is per- pendicular to the plotted equipotential lines. Angammana and Jayaram [13] used COMSOL Multiphysics in two dimensions while modeling the electric field distribution of single and multijet arrangements. Angammana and Jayaram [13] found experimentally that with an increase in voltage, the vertical angle of the straight jet portion increases and the vertical angle increases with an increase in the number of needles. Theron et al. [2] also obtained a similar result while modeling the multiple jets. In this study, electric field distribution of an existing multi- functional electrospinning platform is simulated with Finite Ele- ment Method Magnetics (FEMM) v4.2. The behavior of the electric field is investigated by applying different voltages between the needles and the collector. Electric field strength and potential var- iation between a needle and the collector are investigated. 2. Principle of the machine An electrospinning setup basically consists of three main parts as seen in Fig. 1 [5]. * Corresponding author. Tel.: þ90 5556109527. E-mail addresses: jentzsch@itu.edu.tr, eroljentzsch@gmail.com (E. Jentzsch), gulomer@itu.edu.tr, enerjikalitesi@gmail.com (Ö. Gül), oznergiz@yildiz.edu.tr (E. Öznergiz). Contents lists available at SciVerse ScienceDirect Journal of Electrostatics journal homepage: www.elsevier.com/locate/elstat 0304-3886/$ e see front matter Ó 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.elstat.2012.12.007 Journal of Electrostatics 71 (2013) 294e298