3D Screen Printed Stent Production via Metal Powder Suspension
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Solution Overview
Problem
Current methods for producing coronary stents are time-consuming and energy-intensive due to the numerous process steps involved in forming thin tubes using laser processing or wire EDM.
Innovation Solution
A three-dimensional screen printing method using a metal powder suspension with a binder and suspension aids to form cylindrical hollow bodies, which are then sintered and smoothed through plastic deformation to create stents with improved fixation and reduced surface roughness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods (laser processing or wire EDM) are used to structure thin tubes for stents, then manufacturing precision can be achieved, but production time and energy consumption increase significantly
Solution Approach 1:
The patent changes the fundamental parameters of the manufacturing approach by switching from subtractive methods (laser/wire EDM) to additive 3D screen printing. The metal powder particle size is optimized to 0.7-50 μm, and multiple suspension layers are printed with varying concentrations to achieve precise wall thickness control (50-200 μm) while dramatically reducing production time and energy consumption.
Solution Approach 2:
The patent transitions from 2D laser surface processing to 3D screen printing that builds hollow cylindrical structures layer by layer. This dimensional change enables direct formation of complex stent geometries including variable wall thickness and integrated drug-eluting features during the printing process itself, eliminating subsequent machining steps.
2Strength
If multiple forming and recrystallization processes are used to draw thin tubes, then material strength is improved, but the number of process steps and production complexity increase
Solution Approach 1:
The patent combines multiple functions into the single 3D screen printing process: material deposition, layer-by-layer building, and in-situ sintering. The metal powder suspension is printed directly into the final hollow cylindrical stent shape, and the binder is removed with a single calcination step, eliminating the need for separate drawing, forming, and recrystallization processes while maintaining structural integrity.
Solution Approach 2:
The patent utilizes phase transition during calcination where the organic binder undergoes decomposition and removal, transforming the green printed body into a sintered metal structure. This phase change process consolidates the metal powder particles and binds them together, achieving material strength without requiring multiple mechanical forming and heat treatment steps.
3Reliability
If openings and variable wall thickness are created using conventional methods, then tissue fixation is improved, but production time and material waste increase
Solution Approach 1:
The patent applies local quality by varying the metal powder concentration and layer thickness at different locations during 3D screen printing. This enables direct creation of variable wall thickness (50-200 μm) and strategic openings in the hollow cylinder, providing enhanced tissue fixation where needed while maintaining structural integrity elsewhere, all within a single printing process without additional machining time.
4Reliability
If surface roughness is increased to enhance tissue fixation, then implantation stability improves, but thrombus formation risk increases
Solution Approach 1:
The patent optimizes the metal powder particle size parameter to 0.7-50 μm and controls the layer deposition parameters during 3D screen printing to achieve an optimal surface roughness range. This controlled roughness provides sufficient tissue fixation through mechanical interlocking while maintaining surface characteristics that minimize thrombus formation, balancing implantation stability with biocompatibility.
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 method enables the rapid, cost-effective production of stents with enhanced tissue fixation and reduced thrombus formation risk by forming stents with precise control over layer formation and surface smoothing.
Implementation Method 1
the at least one hollow body is sintered during a heat treatment
Implementation Method 2
the inner and/or outer surface of the at least one sintered hollow body is smoothed by plastic deformation
Data Source
AI summary
In the method according to the invention for producing stents, in particular for cardiovascular intervention, at least one respective cylindrical hollow body is formed from individual layers applied on top of on one another, via a three-dimensional screen printing process with at least one suspension formed using a metal powder and at least one binder. Subsequently, organic components of the at least one suspension are removed from the at least one hollow body and the at least one hollow body is sintered in a heat treatment. The inner and/or outer surface of the at least one sintered hollow body is smoothed by plastic deformation.