Patent ID: 7563396
Filing Date: 2009-07-21
Classification: B29C,B29D,D01D

Abstract:
1. A method of creating a transparent permeable contact lens from a mat of polymer material formed of strands that exhibits the transparency and diffusion characteristics of corneal stromal tissue using the process of electrospinning, comprising the steps of: a. providing a power supply having an alternating output voltage adjustable over a range extending from 4,000 to 12,000 volts, the power supply providing its output to a first and second terminal, b. providing a conductive target having a surface on which to form a base surface (a cornea contact surface) of the contact lens, and a needle having a needle tip, c. electrically coupling the target to the power supply first terminal and the needle to the power supply second terminal to permit the power supply to provide an electric field between the target and the needle tip, d. dissolving a polymer solute in a suitable solvent, e. delivering said solute and solvent solution to the needle tip at a controlled pressure, f. adjusting the output voltage of the power supply to increase the electric field between the needle tip and target until a Taylor cone is formed, but not of a magnitude to result in a corona discharge or coronal effect, g. providing a means to vary the source to target distance, h. moving the needle in a linear direction for a fixed distance and then reversing such motion with respect to the target while at the same time indexing the target utilizing a precision positioner to obtain a desired pattern during electrospinning, and when the desired pattern has been achieved in one axis, the target is rotated ninety degrees and the process repeated, to provide the desired patterns over a region of the target exceeding the perimeter of the contact lens to be formed, depositing the electrospun material as a mat, i. alternating the polarity of the output voltage of the power supply between the target and the needle tip to prevent charge buildup on electrospun fibers and to permit the deposition of electrospun fibers to enable the construction of an electrospun mat of polymer fibers forming the transparent permeable contact lens, and j. trimming the desired patterns over the region of the target exceeding the perimeter of the contact lens to be formed to obtain the lens desired.