DIW Extrusion Head for Viscous Elastomers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 3D printing techniques struggle to produce soft and flexible machine components made from elastomers with complex geometries and internal voids, as existing extrusion systems are limited by material viscosity and inability to handle two-part platinum-cured PDMS materials, resulting in products with unsuitable hardness and strain limits.
Innovation Solution
A 3D print extrusion head with an in-line mixer, heater wings, and a water jacket is developed to mix and cure two-component silicone systems, allowing for the precise extrusion of viscoelastic liquids into complex geometries, featuring a retractable impeller for controlled flow and convective or radiative heating to initiate curing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional molding or injection molding techniques are used, then manufacturing of elastomeric components is achieved, but manual handling introduces uncontrolled variability into manufacturing tolerances and geometric complexity is limited
Solution Approach 1:
The patent changes the physical state parameter of elastomeric materials from cured solid to uncured liquid precursor form, enabling them to be extruded through digital printing systems while maintaining geometric flexibility and precision control through digital modeling
Solution Approach 2:
The patent replaces manual handling operations with an automated digital printing system that uses computer-controlled extrusion to deposit uncured elastomeric material layer by layer, eliminating human intervention variability while achieving complex geometries through digital modeling
2Extent of automation
If FFF or poly-jetting AM techniques are used, then 3D printing of elastomers is achieved, but high viscosity of precursor materials makes them difficult to print and resulting products have weaknesses
Solution Approach 1:
The patent changes the viscosity parameter by using uncured elastomeric precursor materials in liquid form rather than cured elastomers, enabling them to flow through extrusion nozzles while maintaining printability and allowing post-print curing to achieve final mechanical properties
Solution Approach 2:
The patent performs preliminary mixing of two-component platinum-cured PDMS materials before extrusion, ensuring proper chemical composition and homogeneity is achieved before the material is deposited, which prevents printing defects and ensures reliable final product properties
3Ease of operation
If DIW systems are used, then extrusion of viscoelastic liquids is achieved, but commercial systems lack ability to print internal structures or use two-part platinum cured PDMS materials requiring thermal activation
Solution Approach 1:
The patent merges multiple functions into a single integrated extrusion head: mixing chambers for two-component PDMS materials, heating elements for thermal activation of platinum curing, and extrusion nozzle for deposition, all controlled by a single system that can print complex internal structures
Solution Approach 2:
The patent changes the temperature parameter by incorporating heating elements that raise the temperature of two-part platinum-cured PDMS materials to activate the curing reaction during extrusion, enabling use of these specific materials that were previously incompatible with standard DIW systems
4Manufacturing precision
If molded PDMS is used as standard, then Shore hardness under 10 A is achieved, but 3D-printed elastomeric materials are too hard with Shore hardnesses that are too high
Solution Approach 1:
The patent changes the cross-linking density and curing degree parameters by controlling the platinum catalyst concentration, temperature, and curing time during and after printing, allowing adjustment of Shore hardness to match soft molded PDMS standards while maintaining 3D-printed geometric complexity
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 rapid and controlled 3D printing of elastomeric materials with desired hardness gradients, overcoming limitations in material viscosity and geometric complexity, producing parts with Shore hardnesses suitable for soft robotic applications.
Implementation Method 1
heater wings adjacent to the in-line mixer to heat extruded elastomer and initiate curing
Implementation Method 2
convective or radiative heating to initiate curing
Implementation Method 3
water jacket surrounding the in-line mixer to shield it from elevated temperatures
Data Source
AI summary
Disclosed is direct ink write (DIW) print extrusion head for 3D printing of viscous elastomers. The disclosed print extrusion head comprises a mixer assembly, comprising a fluid distribution cap coupled to a carrier, an in-line mixer coupled to the fluid distribution cap. A cooling jacket surrounds the in-line mixer. A nozzle is coupled to the in-line mixer and protrudes below the cooling jacket over a work surface. The position of the nozzle relative to the work surface is changeable. At least one heat source is on the chassis and disposed adjacent to the fluid distribution cap. The at least one heat source comprises a heat guiding element to direct heat to a region onto the work surface below the nozzle.