Multi-Pass Extrusion Artificial Bone Lamellar Structure
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Solution Overview
Problem
Current artificial bones lack both biocompatibility and mechanical strength, failing to replicate the properties of natural bone, which is essential for effective bone grafting in orthopedic surgeries.
Innovation Solution
A multi-pass extrusion process is used to fabricate artificial bones, involving the formation of calcium phosphate-based filaments with a three-layered lamellar structure of hydroxyapatite and t-ZrO2, followed by a hydroxyapatite external shell, and subsequent burning and sintering processes to achieve superior biocompatibility and mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If synthetic materials are used for artificial bone, then manufacturing ease is improved, but mechanical strength deteriorates compared to natural bone
Solution Approach 1:
The patent uses composite materials consisting of calcium phosphate (hydroxyapatite or tricalcium phosphate) and t-ZrO2 in a lamellar structure. This composite approach combines the biocompatibility of calcium phosphate with the mechanical strength of t-ZrO2, achieving both ease of manufacture and superior mechanical properties that replicate natural bone characteristics.
Solution Approach 2:
The invention implements local quality by creating a three-layered lamellar structure with alternating layers of calcium phosphate and t-ZrO2. Each layer has different properties: calcium phosphate provides biocompatibility while t-ZrO2 provides mechanical strength. This local differentiation of material properties within the structure allows the artificial bone to simultaneously achieve ease of manufacture and high mechanical strength.
2Reliability
If bioceramics are used to mimic natural bone, then biocompatibility is improved, but mechanical strength deteriorates
Solution Approach 1:
The patent creates a composite material system combining bioceramics (calcium phosphate) with a strengthening phase (t-ZrO2). The calcium phosphate ensures biocompatibility by being similar to natural bone composition, while the t-ZrO2 reinforcement provides the necessary mechanical strength, resolving the contradiction between biocompatibility and strength.
Solution Approach 2:
The three-layered lamellar structure distributes biocompatible and strength-providing materials in specific locations. Calcium phosphate layers are positioned to ensure biocompatibility with surrounding tissue, while t-ZrO2 layers are strategically placed to provide mechanical reinforcement, achieving both biocompatibility and strength simultaneously.
3Strength
If t-ZrO2 is used to improve mechanical strength, then strength is improved, but biocompatibility deteriorates
Solution Approach 1:
The patent uses composite materials where t-ZrO2 is combined with biocompatible calcium phosphate. The t-ZrO2 provides mechanical strength while the calcium phosphate matrix ensures biocompatibility. This composite approach allows t-ZrO2 to be used for strength enhancement without compromising biocompatibility, as the biocompatible calcium phosphate is in direct contact with the biological environment.
Solution Approach 2:
The lamellar structure creates local quality differentiation where calcium phosphate layers provide biocompatibility at the interface with biological tissue, while t-ZrO2 layers provide mechanical strength in the structural core. This spatial separation of functions allows t-ZrO2 to enhance strength without directly compromising biocompatibility.
4Device complexity
If single-pass extrusion is used, then manufacturing simplicity is improved, but manufacturing precision deteriorates
Solution Approach 1:
The patent segments the extrusion process into multiple passes, with each pass forming a specific layer of the lamellar structure. The first extrusion forms the core structure, the second forms intermediate layers, and the third forms the outer shell. This segmentation allows precise control over the thickness and composition of each layer, achieving high manufacturing precision in the final product.
Solution Approach 2:
The multi-pass extrusion process uses preliminary actions where each extrusion pass prepares the structure for the next pass. The first extrusion creates a preliminary form that is then refined by subsequent passes. This preliminary action approach allows incremental building of complexity while maintaining precision at each stage, ultimately achieving high manufacturing precision.
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
The method results in an artificial bone with properties comparable to natural bone, demonstrating enhanced biocompatibility and mechanical strength, suitable for biomedical applications.
Implementation Method 1
a first burning out process at 600-800° C.; a second burning out process at 900-1100° C.
Implementation Method 2
a sintering process at 1400-1600° C.
Data Source
AI summary
A method for fabricating an artificial bone by multi-pass extrusion, includes: a first extrusion process of forming roll-shaped filaments having sheets of calcium phosphate/calcium phosphate-(t-ZrO2)/t-ZrO2; a second extrusion process of arranging the prepared roll-shaped filaments circularly and extruding the same; and a third extrusion process of forming an external shell of hydroxyapatite (HAp). The method for fabricating an artificial bone allows fabrication of an artificial bone having the biocompatibility and mechanical strength of the natural bone and may be utilized variously in biomedical engineering, medicine and other applications.