Crossed Light Sheet Stereolithography for High-Speed Bioprinting
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Solution Overview
Problem
Current stereolithographic 3D printing techniques, such as DLP and SLA, face challenges with high molecular weight polymer polymerization, low production speed, and cell viability issues when printing with living cells, leading to compromised mechanical, biochemical, and structural properties.
Innovation Solution
A device for stereolithographic 3D printing that uses crossed light sheets from laser generators with wavelengths between 360 nm and 1000 nm, allowing high-resolution and high-speed printing, compatible with bioprinting, and maintaining cell viability above 99% by avoiding shear stress and replicating tissue-like properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If SLA technique is used to polymerize photopolymer, then polymerization of higher molecular weight polymers is achieved with higher accuracy and resolution, but production speed is low
Solution Approach 1:
The patent divides the single laser beam into multiple separate laser beams (first laser beam and second laser beam) that can independently scan and polymerize different regions of the photopolymer. This segmentation allows parallel processing of multiple layers simultaneously, achieving both high resolution through individual beam control and high production speed through concurrent operations.
Solution Approach 2:
The patent introduces a vertical stacking dimension by using multiple laser beams operating at different heights or angles to polymerize multiple layers of photopolymer simultaneously. This dimensional approach enables concurrent polymerization across multiple layers, transforming a single-layer sequential process into a multi-layer parallel process, thereby increasing production speed while maintaining resolution.
2Productivity
If conventional 3D printing processes are used with living cells, then printing is achieved, but cells are subjected to shear stress and compromised viability
Solution Approach 1:
The patent replaces conventional mechanical extrusion or nozzle-based printing methods with a direct laser polymerization system. Instead of forcing material through narrow nozzles that generate shear stress, the laser beams directly polymerize photopolymer droplets or layers in their intended positions. This substitution eliminates mechanical shear stress on cells while maintaining printing capability, achieving both productivity and cell viability.
3Productivity
If DLP technique is used for polymerization, then good accuracy and speed are achieved for low molecular weight polymers, but it has problems for polymerizing polymers of higher molecular weight
Solution Approach 1:
The patent employs multiple laser beams with adjustable parameters (wavelength, power, scanning speed) that can be optimized for different polymer types. By changing these parameters, the system can adapt to polymerize both low molecular weight and high molecular weight polymers effectively, overcoming the limitations of fixed-parameter DLP techniques while maintaining speed and accuracy.
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
The device achieves high-resolution, high-speed 3D printing of photopolymers with living cells, maintaining cell viability and structural integrity, enabling the creation of fully functional tissue surrogates with mechanical and biochemical properties similar to in vivo tissues.
Implementation Method 1
a laser generator (1a, 1b) generating respective light beams (6a, 6b)... modulating said light beams (6a, 6b) into a light sheet... irradiating said light sheets to the container (100) containing said photopolymerizable polymer so that said light sheets are crossed inside said container (100), so that polymerization of said photopolymerizable polymer occurs at the cross-point of said light sheets
Data Source
AI summary
The present invention refers to a device and method for stereolithograpic three dimensional (3D) printing comprising: a) a container adequate for containing a photopolymerizable polymer, b) at least one laser generator emitting a light beam with a wavelength between 360 nm and 1000 nm, c) modulation means for modulating said light beam into at least two light sheets which are matrices of light, and d) means for irradiating said light sheets in the container containing said photopolymerizable polymer; wherein said at least one laser generator is arranged so that said at least two light sheets are crossed inside said container, leading to polymerization of the photopolymerizable polymer at the crossing of said light sheets.