A Scheduled Control Framework for Electrospinning Process in Nanofiber-Based Textile Fabrication

The piezoelectric property exhibited by certain polymers such as polyvinylidene fluoride (PVDF) has been effectively utilized in developing piezoelectric-based film sensors and actuators with application to acoustic transducers, smart fabric and nanomanipulator controllers. The PVDF-based fabric, made of nonwoven nanofibers, is produced by "electrospinning" process in which a jet is ejected in the form of Taylor cone with the application of high voltage to a polymer droplet suspended at the tip of a nozzle. A simple physical model of the fluid jet to investigate the variation of fiber diameter with variation in system parameters is presented in this paper. It is observed that the major parameters that influence the fiber properties are magnitude of the electrostatic field, distance between the nozzle tip and collector grid, infusion rate, concentration of the polymer solution and design of the collector. Presently, the parameterization results from open loop experiments correspond exactly to equations obtained from the model. An image-based feedback control of the electrospinning process based on this model is thus proposed to optimize the nonwoven fiber properties (e.g. fiber diameter). The feedback control is achieved by obtaining and processing images of the jet formation from a high speed camera and analyzing the fiber thickness and jet stability shape.Copyright © 2006 by ASME