Polymer Precipitation in Microparticulate Gels for Support-Free 3D Printing
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Solution Overview
Problem
Existing 3D printing methods, such as FDM, light-assisted extrusion, and solvent-cast 3D printing, face limitations in fabricating freeform structures of thermoplastics due to requirements for support materials, incompatibility with heat-sensitive materials, and slow printing speeds.
Innovation Solution
A method and system for 3D printing thermoplastics using in situ immersion precipitation in microparticulate gels, where an ink composition including thermoplastics, non-thermoplastics, and thermally degradable/thermosensitive polymers is dispensed into an embedding medium, allowing the printed structure to solidify and form a freeform structure without additional support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If FDM 3D printing is used to fabricate freeform structures, then support materials are required to maintain structural integrity, but this increases device complexity and limits design freedom
Solution Approach 1:
The patent introduces a liquid support bath as an intermediary medium that temporarily supports overhanging structures during printing. The bath provides buoyant support without requiring solid support materials, enabling freeform fabrication. After printing, the support bath can be removed or degraded, leaving only the desired structure.
Solution Approach 2:
The patent changes the physical state of the support medium from solid (traditional support materials) to liquid (support bath). This parameter change allows the support to be fluid and removable, eliminating the complexity of solid support structures while maintaining structural integrity during printing.
2Manufacturing precision
If FDM printing is used for freeform fabrication, then printing speed is significantly reduced, but this improves manufacturing precision by allowing careful layer deposition
Solution Approach 1:
The patent replaces the mechanical extrusion and heating system of FDM with a liquid deposition system. The ink is pumped through a nozzle and deposited directly into the support bath, eliminating the need for high-temperature melting and careful layer-by-layer mechanical deposition. This substitution dramatically increases printing speed while maintaining precision through controlled liquid flow.
3Temperature
If solvent-cast 3D printing is used to create thermoplastic models, then printing can be performed at room temperature, but the fabrication rate is limited by solvent evaporation speed
Solution Approach 1:
The patent introduces a support bath as an intermediary that enables rapid solidification of deposited ink without relying on slow solvent evaporation. The bath medium facilitates immediate phase separation and precipitation, allowing room temperature printing at high speeds while maintaining structure stability.
Solution Approach 2:
The patent utilizes phase transition from liquid ink to solid precipitate upon contact with the support bath medium. This phase change occurs rapidly through immersion precipitation rather than slow evaporation, dramatically increasing fabrication rate while maintaining room temperature operation.
4Shape
If light-assisted extrusion printing is used, then photocurable materials can be printed with good shape retention, but heat-sensitive materials become incompatible
Solution Approach 1:
The patent changes the curing mechanism from photochemical (light-assisted) to chemical precipitation through immersion in support bath. This parameter change in the solidification process eliminates the need for photocurable materials, enabling the use of thermoplastics and heat-sensitive materials that were previously incompatible.
Solution Approach 2:
The patent replaces the light-based curing system with a chemical precipitation system using support bath medium. This substitution removes the requirement for photocurable materials and UV light sources, expanding material compatibility to include thermoplastics and heat-sensitive polymers while maintaining excellent shape retention.
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 fabrication of freeform thermoplastic structures without external support, overcoming compatibility and speed limitations, and allowing for controlled porosity and internal structure formation.
Implementation Method 1
dispensing the ink composition through a nozzle into the embedding medium to precipitate a printed structure from the ink composition
Data Source
AI summary
Herein disclosed is a method of printing a 3D freeform structure in an embedding medium. The method includes providing an ink composition in a nozzle, wherein the ink composition includes a thermoplastic, a non-thermoplastic, a thermally degradable polymer, and/or a thermosensitive polymer, dissolved in a solvent; dispensing the ink composition through a nozzle into the embedding medium to precipitate a printed structure from the ink composition, wherein the ink composition exits from the nozzle directly in the embedding medium; and maintaining the printed structure in the embedding medium until the immersion precipitation is completed for forming the 3D freeform structure. A system operable to carry out the method is also disclosed. The system includes a syringe coupled to a nozzle.