Electrospun Stent Coating for Inner and Outer Surface Coverage
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Solution Overview
Problem
The existing methods for applying fabric or fabric-like material to the inner and outer surfaces of stents, such as those used in prosthetic heart valves, are time-consuming and laborious, requiring sewing and suturing, which increases production costs.
Innovation Solution
A method using electrospinning techniques to apply polymeric material to both the inner and outer surfaces of a stent by rotating the stent and a supporting mandrel, allowing the polymeric threads to form a coating that covers both surfaces without the need for pre-made cloth and sewing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sewing methods are used to apply fabric to stents, then the material application is secure and durable, but the process becomes time-consuming and labor-intensive
Solution Approach 1:
The patent replaces the mechanical sewing process with an electrospinning process that uses electrical fields to deposit polymeric material directly onto the stent. The electrospinning system uses a high-voltage power supply to create an electric field between the spinneret and collector, causing polymer solution to form charged jets that solidify into fibrous material on the stent surface, eliminating the need for mechanical needle and thread operations.
Solution Approach 2:
The patent changes the physical state and deposition mechanism by using electrospinning parameters (voltage, flow rate, distance, rotation speed) to control material application. By adjusting these parameters, the system achieves controlled fiber diameter, deposition rate, and material distribution, replacing the binary secured/not-secured outcome of sewing with continuous controllable deposition.
2Strength
If sewing methods are used to apply fabric to stents, then the material attachment is strong, but the labor time and production costs increase
Solution Approach 1:
The patent replaces the mechanical sewing process with an electrospinning process that uses electrical fields to deposit polymeric material directly onto the stent. The electrospinning system uses a high-voltage power supply to create an electric field between the spinneret and collector, causing polymer solution to form charged jets that solidify into fibrous material on the stent surface, eliminating the need for mechanical needle and thread operations.
Solution Approach 2:
The electrospinning process allows for continuous deposition of material onto the stent as it rotates, eliminating the discrete, step-by-step nature of sewing operations. The polymer solution flows continuously from the spinneret and deposits continuously on the stent surface, enabling uninterrupted material application that reduces total processing time while maintaining attachment quality.
3Ease of operation
If pre-made cloth is sewn to stents, then the application process is straightforward, but it requires complex sewing operations and increases production complexity
Solution Approach 1:
The patent replaces the mechanical sewing process with an electrospinning process that uses electrical fields to deposit polymeric material directly onto the stent. The electrospinning system uses a high-voltage power supply to create an electric field between the spinneret and collector, causing polymer solution to form charged jets that solidify into fibrous material on the stent surface, eliminating the need for mechanical needle and thread operations.
Solution Approach 2:
The patent introduces polymer solution as an intermediary medium that is transformed into fibrous material through the electrospinning process. Instead of directly sewing pre-made cloth to the stent, the system uses polymer solution that is deposited and then solidifies into the desired fabric-like structure, providing a intermediate state that simplifies the overall process.
4Productivity
If electrospinning is used to apply material to stents, then labor time and production costs are reduced, but the process requires precise control of material properties
Solution Approach 1:
The patent implements feedback control through the rotation system where the stent's rotational speed is controlled to ensure uniform material distribution. The rotation provides continuous movement that distributes the electrospun material evenly across the stent surface, and the system can adjust rotation speed based on deposition rate to maintain consistent material properties and thickness throughout the process.
Solution Approach 2:
The patent changes the physical state and deposition mechanism by using electrospinning parameters (voltage, flow rate, distance, rotation speed) to control material application. By adjusting these parameters, the system achieves controlled fiber diameter, deposition rate, and material distribution, replacing the binary secured/not-secured outcome of sewing with continuous controllable deposition.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces labor time and production costs by efficiently covering the stent surfaces with polymeric material, providing a seamless and secure attachment without the need for manual sewing.
Implementation Method 1
A voltage is placed between the spinneret and the mandrel. An electrospun material is applied to at least a portion of the stent external surface and to at least a portion of the mandrel
Data Source
AI summary
Methods for applying polymeric material to a stent are disclosed. A mandrel is coupled to a stent body. The stent body comprises an inner surface defining a cavity and an outer surface opposing the internal surface. The stent body also has a length along an axis defined by the mandrel between a first end of the stent body and a second end of the stent body. An electrospun material is applied to at least a portion of the stent external surface and to at least a portion of the mandrel to form a coating sheet. A portion of the coating sheet extends from at least one of the first end or second end of the stent to the mandrel. One or both of the stent and the mandrel are moved to apply at least some of the portion of the coating sheet onto the internal surface of the stent body.