Acousto-Optic Laser Scanning for High-Resolution Additive Manufacturing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing additive manufacturing technologies face a tradeoff between fabrication speed and manufacturing resolution, with higher resolution leading to slower processes and attempts to improve speed through increased laser beam fluence often resulting in cross-curing issues and increased complexity.
Innovation Solution
The use of fast acousto-optic deflectors (AODs) with controllable output intensity and orthogonal operation, in conjunction with controllable deflectors, allows for scanning at higher resolution without increasing build time by dividing the laser beam into subpixels and adjusting intensity profiles in real-time, enabling arbitrary beam profiles and reduced cross-curing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high resolution scanning is achieved using traditional galvanometer mirrors, then manufacturing precision is improved, but fabrication speed deteriorates
Solution Approach 1:
The patent replaces traditional mechanical galvanometer mirror systems with acousto-optic deflectors (AODs) that use acoustic waves to control laser beam deflection. This substitution eliminates mechanical inertia limitations, enabling scan rates exceeding 1 MHz while maintaining high spatial resolution, thus simultaneously improving both manufacturing precision and fabrication speed
Solution Approach 2:
The patent changes the fundamental operating parameters of the deflection system by using acoustic frequency modulation instead of mechanical angle modulation. The AODs can rapidly adjust beam position and intensity by changing acoustic wave parameters, enabling high-speed scanning with precise control over laser fluence distribution, thereby resolving the speed-resolution tradeoff
2Productivity
If laser beam fluence is increased to improve fabrication speed, then productivity is improved, but cross-curing issues and harmful effects increase
Solution Approach 1:
The patent implements spatially varying laser beam intensity profiles by controlling the amplitude of acoustic waves in different regions of the AOD. This enables precise local adjustment of fluence distribution, ensuring that each voxel receives exactly the required energy dose without excess that would cause cross-curing, thus maintaining high productivity while eliminating harmful effects
Solution Approach 2:
The system incorporates real-time control of laser parameters based on the digitally controlled acoustic wave modulation. The controller adjusts beam intensity and position with precise feedback control, ensuring optimal fluence delivery that maximizes fabrication speed while preventing cross-curing by avoiding both under-exposure and over-exposure conditions
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 enhances manufacturing resolution and speed, allowing for precise control over beam intensity and shape during scanning, improving microstructure and reducing cross-curing issues while maintaining high efficiency and flexibility.
Implementation Method 1
at least one acousto-optic deflector (AOD) having a second scan rate faster than the first scan rate
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An additive manufacturing device may include a laser source configured to generate a laser beam, a build material holder configured to hold an additive build material, a controllable deflector having a first scan rate, an AOD having a second scan rate faster than the first scan rate, and a controller. The controller may be configured to control the controllable deflector and the AOD to scan the laser beam relative to the build material holder to additively manufacture a workpiece in successive layers from the additive build material.