Polycrystalline Mesoscale Components via Gel-Casting
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Solution Overview
Problem
Current manufacturing techniques are inadequate for producing polycrystalline complex-shaped mesoscale components with high tolerances and material diversity, particularly failing to maintain precision in high aspect ratio components and limited to crystalline and amorphous silicon materials.
Innovation Solution
A process involving gel-casting of ceramic or metal slurries in a polymerizable monomer within a photoresist mold, followed by heating to form sintered polycrystalline mesoscale components with a composite interface, allowing for the creation of components with specific geometric ratios and edge resolutions, and enabling the use of various materials including metals and ceramics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If MEMS etch and lithography techniques are used to form complex shapes, then material choices are limited to crystalline and amorphous silicon and inorganic silicon compounds, but the ability to produce complex shapes is improved
Solution Approach 1:
The patent changes the fundamental parameter of material state from crystalline/amorphous to polycrystalline, and employs gel-casting instead of etching to form components. This allows the use of diverse materials including metals, ceramics, and composites while maintaining the ability to produce complex mesoscale shapes with high precision
Solution Approach 2:
The patent replaces the mechanical etching process with a casting process using gel-casting technology. This substitution enables the formation of complex shapes through mold-based casting rather than material removal, thereby expanding material compatibility to include polycrystalline metals and ceramics that cannot be etched
2Shape
If MEMS etch and lithography techniques are used, then complex shapes can be formed, but tolerances are not maintained in high aspect ratio components
Solution Approach 1:
The patent uses photoresist molds to pre-defin e the precise geometry and tolerances of high aspect ratio components before casting. The mold structure itself establishes the dimensional constraints, ensuring that tolerances are maintained throughout the casting process without requiring post-processing adjustments
3Ease of manufacture
If conventional fabrication techniques such as CNC machining and precision wire EDM are used, then manufacturing capability is improved, but sufficient control to provide complex shapes and small feature sizes with high tolerances is lacking
Solution Approach 1:
The patent transitions from subtractive machining to additive casting by introducing a mold dimension. The photoresist mold provides a third dimensional constraint that enables precise control of complex shapes and small features, achieving tolerances unattainable through conventional machining of mesoscale components
4Shape
If chemical etching, focused ion beam etching or fast atom beam machining are used, then complex shapes can be produced, but only single components are produced at a time and material choices are limited
Solution Approach 1:
The patent segments the production process into mold preparation and casting stages, allowing multiple molds to be prepared simultaneously. Multiple components can then be cast in parallel using the same or different molds, significantly increasing production rate compared to sequential etching processes while maintaining complex shape capability
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
Enables the production of polycrystalline mesoscale components with complex geometries and high precision, achieving aspect ratios of 20-80:1:0.5-10 and edge resolutions of 0.1-2 microns, suitable for applications requiring strength and resistance to catastrophic failure, such as in minimally invasive surgery and subterranean sampling.
Implementation Method 1
a slurry of particles of ceramic, metal, or a combination thereof in a polymerizable monomer in an amount to form a polymer that imparts strength to the mold fill
Implementation Method 2
the gel cast mold fill is heated to remove the polymer and form the polycrystalline sintered mesoscale component
Data Source
AI summary
A polycrystalline mesoscale component, formed through a process including filing a mold cavity formed in a photoresist with a mold fill, is provided with an overall length L divided into multiple segments with a second segment extending from a first segment at a nonlinear angle. The first segment has a first segment height H1 and a first segment thickness T1, while the second segment has a second segment height H2 and a second segment thickness T2, with the lesser of H1 and H2 defining a minimum segment height Hmin and the lesser of T1 and T2 defining a minimum segment thickness Tmin. The resultant component has a ratio of L:Hmin:Tmin of 20-80:1:0.5-10 where Hmin is between 5 and 500 microns. In specific instances, the nonlinear angle is acute, the multiple segments are rectilinear in cross section, and a segment thickness has an edge resolution of between 0.1 and 2 microns.