Negative 3D Printing via Laser Material Removal
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Solution Overview
Problem
Current three-dimensional (3D) fabrication techniques face limitations such as the need for deep resin pools, complex mechanical steps for layer separation, and restricted material versatility and production rates.
Innovation Solution
A method and system for 3D printing that involves coating a film with material, removing excess material digitally using a laser, and exposing the coated film to a light source during contact with a sample to form the next layer of the 3D object, allowing for continuous production and multiple material use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If new layers are formed at the top surface of the growing object, then the object can be constructed layer by layer, but a deep pool of liquid resin is required and the object must be submerged and reconstituted before each layer formation
Solution Approach 1:
The patent inverts the conventional 3D printing approach by forming layers at the bottom surface of the growing object rather than at the top. This inversion eliminates the need for a deep resin pool and submersion steps, as the build plate with solidified layers is simply lifted out of a shallow resin pool after each layer is formed.
Solution Approach 2:
The patent uses a shallow resin pool that is excessive only for bottom-layer formation but insufficient for complete object submersion. This partial action approach allows layer formation without requiring the entire object to be submerged, reducing the resin pool depth while maintaining manufacturing capability.
2Volume of stationary object
If new layers are formed at the bottom of the growing object, then the need for a deep well is eliminated, but extreme care and additional mechanical elements are required to separate the solidified layer from the bottom plate
Solution Approach 1:
The patent extracts the separation function from complex mechanical elements and transfers it to the resin pool itself. By designing the resin pool with specific surface properties and using controlled lifting motion, the resin pool actively facilitates layer separation without requiring additional mechanical separation devices.
Solution Approach 2:
The resin pool serves multiple functions including layer formation, layer separation, and support during lifting. The system uses the resin's own properties and the lifting motion to achieve separation, making the resin pool self-sufficient for the separation task without external mechanical assistance.
3Reliability
If elastic separation layers or sliding build plates are used to separate solidified material, then non-destructive separation is achieved, but the apparatus is complicated and the process is slowed down
Solution Approach 1:
The patent eliminates interruptions in the fabrication process by removing complex separation mechanisms. The continuous lifting motion of the build plate maintains continuous useful action, allowing layer formation and separation to occur in a seamless workflow without stopping for mechanical separation operations.
Solution Approach 2:
The patent replaces complex mechanical separation systems (elastic layers, sliding plates) with a simpler lifting mechanism. The separation function is achieved through the interaction between the lifted build plate and the resin pool, substituting mechanical separation complexity with a more straightforward lifting action.
4Productivity
If inhibitor-based techniques are used to create interface zones, then continuous production is suggested, but the rate of production is limited by inhibitor concentration, resin viscosity, and UV light power
Solution Approach 1:
The patent extracts the production rate limitation by removing the inhibitor-based interface zone mechanism. Instead of relying on inhibitor diffusion and consumption rates, the patent uses direct photopolymerization at the build plate surface, eliminating the kinetic constraints imposed by inhibitor concentration and diffusion.
Solution Approach 2:
The patent creates a new layer by forming a copy of the desired layer geometry directly on the build plate surface through photopolymerization. This direct copying approach eliminates the need for inhibitor-based interface zones and their associated production rate limitations.
5Ease of manufacture
If conventional 3D printing techniques are used, then three-dimensional objects can be fabricated, but support materials and complex mechanical steps are required
Solution Approach 1:
The patent converts the potential harm of resin adhesion to the build plate into a benefit. The same adhesion that could prevent separation is used to ensure complete layer formation and detachment as a unified layer, eliminating the need for support materials and converting adhesion from a problem into a solution.
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 significantly reduces waste, eliminates the need for support materials, and enhances printing speed and versatility, enabling the production of complex 3D objects with improved efficiency and material flexibility.
Implementation Method 1
removing excess material digitally using a laser
Implementation Method 2
exposing the coated film to a light source during contact with a sample to produce the sample's next layer
Data Source
Figure 1
Figure 2
Figure 3a
AI summary
Methods and apparatus for the fabrication of solid three-dimensional objects from liquid polymerizable materials at high resolution. A material (202) is coated on a film (204) non digitally, excess material is removed digitally, by laser, leaving a negative image of a layer to be printed, and the image is then engaged with existing portions of an object (220) being fabricated and exposed to a non-digital UV curing light source. Since the only part of digitizing is the material removal, and this part is done by laser, the speed of printing and the robustness of the manufacturing process is improved significantly over conventional additive or 3D fabrication techniques.