Additive Fabrication Device Swept Fill Scan Path Optimization
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Solution Overview
Problem
Conventional additive fabrication techniques, such as stereolithography, often result in differential cure artifacts and lower surface finish quality due to time-dependent material solidification and motion-control hysteresis, particularly when forming cross-sectional areas with voids, leading to visible discontinuities and material shrinkage issues.
Innovation Solution
Configuring the additive fabrication device to move the actinic radiation source over voids while deactivating it, employing a 'swept fill' technique that optimizes path selection to ensure adjacent solid regions are formed close together in time, reducing the difference in formation time between adjacent scan lines and mitigating visible artifacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional additive fabrication techniques are used to form cross-sectional areas with voids, then the fabrication process can be completed, but differential cure artifacts and surface finish quality deteriorate due to time-dependent material solidification and motion-control hysteresis
Solution Approach 1:
The patent applies preliminary action by pre-calculating and optimizing the scan path configuration before fabrication begins. The system determines optimal scan paths that minimize time differences between adjacent scan lines in advance, allowing the fabrication device to follow predetermined optimized paths that reduce differential cure artifacts and improve surface finish quality
Solution Approach 2:
The patent changes the temporal parameter of the fabrication process by adjusting scan speeds and path configurations to minimize time differences between adjacent scan lines. This parameter optimization ensures that adjacent solid regions are formed simultaneously, reducing time-dependent artifacts and improving both surface finish quality and artifact reduction
2Productivity
If the actinic radiation source moves continuously across the liquid photopolymer, then fabrication speed is maintained, but time-dependent artifacts and material shrinkage issues occur due to uneven solidification times
Solution Approach 1:
The patent applies dynamics by making the scan path configuration adaptive and variable rather than fixed. The system dynamically adjusts scan paths based on the specific geometry of the object being fabricated, optimizing the motion control to minimize time differences between adjacent scan lines while maintaining high fabrication speed and object fidelity
Solution Approach 2:
The patent implements feedback through motion control hysteresis compensation. The system monitors and adjusts the motion control parameters to account for hysteresis effects, ensuring that scan paths are optimized in real-time to minimize time-dependent artifacts while maintaining high fabrication speed
3Adaptability or versatility
If adjacent scan lines are formed at significantly different times, then the fabrication process can handle complex geometries, but visible discontinuities and differential cure artifacts appear on the surface
Solution Approach 1:
The patent applies segmentation by dividing the fabrication process into optimized scan line segments. The system segments the scan paths into discrete units and optimizes each segment's timing and configuration to minimize time differences between adjacent lines, thereby maintaining surface continuity and reducing visible discontinuities while handling complex geometries
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 improves the surface finish and reduces differential cure artifacts, resulting in higher object fidelity and quality by ensuring that adjacent solid regions are formed simultaneously, thereby minimizing time-dependent artifacts and enhancing the aesthetic and structural integrity of the fabricated parts.
Implementation Method 1
Exposure to actinic radiation cures a thin layer of liquid resin, which causes it to harden, change physical properties, and adhere to previously cured layers or the bottom surface of the build platform
Data Source
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AI summary
According to some aspects, techniques for reducing time-dependent fabrication artifacts in additive fabrication are provided. By selectively activating and deactivating an element of an additive fabrication device that forms solid material, adjacent regions of material may be formed sequentially, thereby reducing time-dependent fabrication artifacts at the cost of increasing the time taken to fabricate an object. In some embodiments, selective activation and deactivation of an element of an additive fabrication device that forms solid material may be performed to a subset of an object being fabricated based on an assessment of which portions of an object will be visible upon fabrication.