Engineering Commons^™

Fem Of Electrospinning Compared To Inkjet Printing Model, Maikel Ghaly

Theses

Electrospinning is a process that uses electrostatic forces to produce nanofibers, or fibers in the nano scale. Nanofibers are widely used in many fields like drug delivery and tissue engineering. Nowadays, it is gaining much attention in the research community as an advantageous process. However, there are many parameters that controlnanofiber formation. This research intends to develop a model of electrospinning on the basis of an inkjet printer technique by using a computer aided simulation (COMSOL). Inkjet printing is a technique that delivers small volumes at high repetitions which can betransported by electrostatic forces through the air onto their intended …

Developing A Labview Based Thermally Stimulated Current (Tsc) Controller To Measure Residual Charge In Electrospinning, Jai Abhishekh Veezhinathan

Theses

Electrospinning is an electrohydrodynamic process for the fabrication of nanofibers which are widely used in therapeutical tissue engineering approaches. It utilizes the potential difference of an electrostatic field to overcome the surface tension of the polymer solution to extrude a fine jet of fluid which deposits on the grounded collector as a nanofiber mat. Using this process, nanofibers with diameters less than a micron can be produced.

Previous studies have shown the presence of residual charge in electrospun nanofibers. The presence and decay of residual charge during cell culture media is still unknown. In an attempt to clarify the presence …

Current Measurements In Electrospinning, Clinton K. Lien

Theses

Electrospinning provides an economical method of producing nanofibers. The current carried by the main spinning jet is found to be one of the factors in determining the diameter of the fiber product. However, current sources such as the corona discharge and secondary jets will lead to a systematic overestimation of the actual current value.

In this research, experiments with different configurations are set up to investigate the influence of various parameters on the measured current. It is noticed that the measured current is nearly independent on the flow rate of the solution and the external cover. A large amount of …

The Incorporation Of Electrohydrodynamics And Other Modifications Into A Dry Spinning Model To Develop A Theoretical Framework For Electrospinning, Yuki Imura

Dissertations

The objective of this research was the development of a mathematical model of the electrospinning process using dry spinning modeling principles as a basis. This model is directed at the identification of parameters which influence final fiber characteristics, e.g., solvent concentration, temperature, spin line tension, and electric field. Preliminary computer simulations were performed; however, the generated data was inconclusive and was determined to be due in part to the complexity of the modeled system and the subsequent computational difficulties encountered. Although a comprehensive computational model of the electrospinning process has not yet been demonstrated, the theoretical development that was undertaken …

A 3-Dimensional Vascularized Cardiac Tri-Culture Model Using Chitosan Nanofiber Scaffolds, Ali Hussain

Dissertations

The development of an in vitro tissue model that can mimic the 3-dimenisonal (3-D) cellular architecture and mosaic of myocardial tissue holds great value for cardiac tissue engineering, modeling, and cardiovascular drug screening applications. The main objective of this project was to develop a 3-D vascularized cardiac tissue model in vitro for improved survival and function.

The cellular mosaic of the myocardial tissue demands the intricate integration of an extracellular matrix-like scaffold, cellular constituents, and biological factors. The first aim of the research was to fabricate and characterize a biodegradable chitosan nanofiber scaffold that would resemble the extracellular matrix (ECM) …

Fabrication Of Hydroxyapatite-Biodegradable Polymer Scaffolds By Electrospinning For Potential Bone Tissue Application, Satomi Suzuki

Theses

The purpose of this study is to determine the potential of combining hydroxyapatite (HA) and polymers to form synthetic composite materials used for bone tissue engineering applications. In this study, ceramic-biodegradable polymer composites are fabricated by electrospinning method. The biodegradable polymers used are poly(L-lactic acid) (PLLA), and poly(lactide-co-glycolide) (PLGA). Two types of HA-polymer solutions are first prepared to achieve HA weight percentage of 0, 10, and 25%of the total combined weight of HA and PLLA, and HA and PLGA. The solutions are electrospun to form nanofibrous mats incorporated with HA powder. A biomimetic process was also conducted as a …

Fabrication Of Aligned Nanofiber Yarns, Mats And Isolation Of Single Nanofiber In Electrospinning, Venkatesh T. Nathilvar

Theses

Electrospinning has been extensively used as an effective technique for the fabrication of submicron and nanometer scale polymeric fibers. In spite of technological advances in electrospinning, creating a highly aligned fiber structure is a tough target to be achieved because of the chaotic motion of the electrospinning jet. In this study, two different techniques have been adopted to form a highly aligned nanofibrous scaffolds. Using these methods highly aligned fiber yams and mats are produced from Cellulose Acetate (CA) in a mixed solvent of acetone and water. In both the techniques the nanofibers suspend over the gap in a highly …

Electrospinning Of Biphasic Biopolymer And Polymer : A Feasibility And Characterization Study, Sherry Hsiu-Ying Wang

Theses

Electrospinning of polymeric materials have been experimented to achieve nanoscaled diameters. The approaches to the current study are to combine a natural material such as collagen with synthetic materials and determine if the interactions between the materials can be used in the electrospinning process. Collagen is a material of choice due to its biocompatibility. When collagen is combined with polymer, Polyethylene Oxide (PEG), the fiber diameters ranged from 150nm to one micron. The fibers produced have shown drastic phase separation. The next study involved using a duel solvent system to electrospin fibers. The polymer of choice is Poly (1-lactic acid) …

Characterization Of Mechanical Behavior Of Electrospun Non-Woven Mats, Ajitha Patlolla

Theses

Electrospinning is a simple and efficient method for the production of nanometer to micrometer fibers. While the process of electrospinning has been known for over half a century, current understanding of the process and those parameters that affect the properties of the fibers is very limited. Not much work has been done in the field electrospinning process to study the mechanical properties of nonwoven mats produced and to study parameters affecting their properties.

In the first part of this thesis electrospun nonwoven mats made of poly(lactides) solutions were characterized based on their mechanical behavior in biorelevant conditions. In the second …

Fabrication Of Nanofiber Scaffolds By Electrospinning And It's Potential For Tissue Engineering, Shobana Shanmugasundaram

Theses

Electrospinning is a fabrication process that uses an electric field to control the deposition of polymer fibers on to a target substrate. This electrospinning strategy can be used to fabricate fibrous polymer mats composed of fiber diameters ranging from several microns down to tens of nanometers. This study assesses the potential of electrospinning, as an alternative scaffold fabrication technique for tissue engineering applications. In this study, electrospinning is adapted to produce tissue-engineering scaffolds of two different size ranges composed of non-woven poly-L-lactide (PLLA) nanofibers and as a first study, the potential use of these scaffolds as tissue engineering scaffolds was …

Characterization Of Electrospun Dlplga Nanofibers For A Drug Delivery System For Intracranial Tumors And Avms, Kimberly A. Griswold

Theses

Electrospinning processes apply electric fields to a polymer solution in order to produce strands of polymer in the nanoscale range. These polymer fibers are manipulated for their porosity, high surface area, fineness and uniformity. In order to create the ideal drug delivery system for intracranial arteriovenous malformations (AVMs) and tumors, D, L poly-(lactice-poly-glycolide) (DLPLGA) nanofibers were electrospun in a tetrahydrofuran (THF) solvent. Three different concentration ratios of DLPLGA, 85/15, 80/20, and 75/25 were analyzed to obtain the prime base for drug annexation. 1 ,3-bis (2-chloroethyl)- 1 -nitrosourea (BCNU) was then codissolved with the DLPLGA nanofibers to form a homogenous solution, …