Formation of oriented or aligned micro-and nanofibers using biocompatible materials opens the possibility to obtain engineered tissues that can be used in medicine, environmental engineering, security and defense, among other applications. Pectin, a heteropolysaccharide, is a promising material to be incorporated into the fibers because, besides being biocompatible, this material is also biodegradable and bioactive. In this work, the formation of oriented fibers using solutions containing pectin and polyethylene oxide (biocompatible polymers), and chloroform (as the solvent) is investigated. The injection of solution into an intense electric field defined between two parallel electrodes was used to obtain oriented fibers. This novel approach is a modification of the conventional electrospinning process. The presence of pectin in the fibers was confirmed by FTIR analysis. Fibers with diameters of hundreds of nanometers and several centimeters long can be collected. The incorporation of pectin leads to a higher variation of the diameter of the fibers, and a trend to larger fiber diameters. This behavior can be related to the presence of pectin clusters in the fibers.

The formation of oriented fibers using injection of polymeric solutions inside electric fields defined by two parallel suspended electrodes is investigated. Image analyses of polymeric streams (using the injection of a large amount of polymer) are compared with electric field distributions obtained with numerical simulation (COMSOL Multiphysics). A sequence of formation of polymer streams that follow electric field stream lines is observed. Initially a stream moves towards the positive electrode. Then, streams are ejected from the positive electrode towards the grounded electrode. Oriented fibers with diameters in the range of nano- to micrometers result connected between electrodes (separated by several centimeters) and can be easily collected/transferred keeping their orientation. This type of fibers finds applications in topics such as tissue and sensors engineering. Also, the fibers are flexible and can be shaped with the stylus of a profilometer without rupture.

Electrospinning has been considered a straightforward way of producing nano and micro fibers. In this work we are analyzing variations of the conventional electrospinning process to better understand and explore the effect of electrostatic interactions. The variations we are investigating include the insertion of polymer inside the electric field keeping the capillary for polymer injection at a floating potential. In this way we are exploring different mechanisms of charge induction. Also, we are using different setup configurations including: same as electrospinning, parallel macro and micro electrodes. Image analysis reveals the occurrence of instabilities/oscillations of the polymer flow (caused by redistribution of charges) leading to the deposition of fibers and improving polymer flow directionality. Fiber orientation on the substrate can be obtained using parallel macro and micro electrodes.

Formation of oriented fibers using injection of polyethylene oxide (PEO) solutions inside electric fields defined by two parallel suspended electrodes is investigated. Images of streams formed with the injection of a large amount of polymeric solution reveal good agreement with electric field distributions obtained with numerical simulation (COMSOL Multiphysics) when appropriate boundary conditions are defined. Oriented fibers with diameters in the range of hundreds of nanometers to micrometers result connected between electrodes (separated by several centimeters) and can be easily collected/transferred keeping their orientation. Fibers with this characteristic find applications in topics such as tissue and sensors engineering. Also, the fibers are flexible and can be shaped with the stylus of a profilometer.

Electrospinning has been considered a straightforward way of producing nanofibers. In this work we are analyzing non-conventional approaches of the electrospinning process to better understand and explore the effect of electrostatic interactions. The processes we are investigating include the insertion of polymer inside the electric field keeping the capillary for polymer injection at a floating potential. Also, we are investigating different electrode configurations including: same as electrospinning (with and without polarization of the capillary for polymer injection), parallel macro electrodes and, microelectrodes (with tip to tip alignment). Image analysis reveals the occurrence of instabilities/oscillations of the polymer flow (caused by redistribution of charges). Improvement of polymer flow directionality and fiber diameter reduction are observed in comparison with conventional electrospinning. Fiber orientation can be obtained using parallel macro electrodes and micro electrodes.