Ultrashort-Pulse Laser Cutting of Fuel Cell Layer Stacks

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Solution Overview

Problem

Conventional methods for cutting fuel cell stacks using rotating blades are prone to wear, leading to imprecision, incomplete cuts, and require costly and cumbersome changes in blade geometry, while also risking contamination.

Innovation Solution

A method using a laser with pulsed beams of specific parameters (pulse duration < 10 ps, fluence > 127 J/cm², and pulse overlap > 50%) for precise cutting of fuel cell stacks without mechanical contact, allowing for easy pattern changes and reduced damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a rotating blade is used to cut the stack, then the cutting operation can be performed continuously, but the blade wears rapidly leading to imprecision and incomplete cuts

Engineering Contradiction:
Improvecontinuous cutting operationVSAvoidcutting precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical rotating blade cutting system with a laser-based cutting system. The laser beam eliminates the mechanical contact and wear issues while maintaining continuous cutting capability. The laser parameters (pulse duration < 10 ps, fluence > 127 J/cm²) are optimized to achieve precise cutting without the degradation problems of mechanical blades.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the blade geometry is changed to cut different patterns, then new cutting patterns can be achieved, but producing distinct and specific rolls is cumbersome and costly

Engineering Contradiction:
Improvecutting pattern varietyVSAvoidblade change complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent implements a dynamic, software-controlled laser system that can change cutting patterns without physical hardware changes. The laser beam can be programmed to follow different paths and patterns, providing versatility while eliminating the need to manufacture and store multiple specialized mechanical blades or rolls.

Inventive Principle:
Principle #15Dynamics

3Productivity

If a mechanical blade is used to cut the stack, then the cutting operation can be performed, but the blade physically touches the fuel cell parts causing contamination

Engineering Contradiction:
Improvecutting operationVSAvoidcontamination
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical blade that physically contacts the workpiece with a non-contact laser cutting system. The laser beam performs the cutting operation without touching the fuel cell parts, thereby eliminating contamination while maintaining productive cutting operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 laser cutting method maintains high precision and efficiency over time, reduces contamination risk, and optimizes production line flexibility by eliminating the need for mechanical blade changes, achieving clean cuts at the atomic scale.

Implementation Method 1

using a laser generating a pulsed beam directed toward the stack, piloting the beam so as to follow a pattern to be cut in the stack, wherein the pulse duration of the beam is lower than 10 ps, wherein the fluence of the beam is greater than 127 J/cm²

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP4585354A1Method for cutting a stack of several layers
Publication Date: 2025.07.16 TOYOTA JIDOSHA KK
  • EP4585354A1 patent drawingFigure 1~3
  • EP4585354A1 patent drawingFigure 4~5
  • EP4585354A1 patent drawingFigure 6~7

AI summary

A method for cutting a stack of at least two layers, the method comprising: using a laser (40) generating a pulsed beam directed toward the stack (10), piloting the beam so as to follow a pattern to be cut in the stack (10), wherein the pulse duration of the beam is lower than 10 ps; wherein the fluence (Φ) of the beam is greater than 127 J/cm2, and wherein the pulse overlap (θ) of the beam between two successive pulses is greater than 50%.