Strobe Light Drop Characterization for 3D Printing Jitter

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Solution Overview

Problem

Current 3D printing technologies, particularly magnetohydrodynamic (MHD) printers, face challenges with non-uniform jetting of liquid metal drops, leading to inferior quality objects due to manual and error-prone detection of drop jitter.

Innovation Solution

A method and system that uses a synchronized light source to illuminate and capture images of drops, employing image processing techniques such as Canny edge detection and binary masking to detect and characterize drop size and location differences, allowing for real-time adjustment of printer parameters to mitigate drop jitter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual detection of drop jitter is used, then the system complexity is low, but the measurement precision and reliability are poor

Engineering Contradiction:
Improvedrop jitter detection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

A strobe light is introduced as an intermediary to illuminate the liquid metal drops during flight. The light pulses are synchronized with the drop ejection frequency, creating visible images of each drop at specific positions. This intermediary enables optical detection without requiring direct contact or complex sensors near the nozzle, thereby improving measurement precision while keeping the detection system relatively simple.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The manual visual inspection method is replaced with an automated optical detection system. A camera captures images of the illuminated drops, and image processing algorithms automatically analyze drop position and size. This substitution eliminates human error and subjectivity, significantly improving measurement precision and reliability.

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

2Measurement precision

If high-speed camera is used to capture drops, then the measurement precision is improved, but the use of energy increases

Engineering Contradiction:
Improvedrop characterization accuracyVSAvoidcamera energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

Instead of continuous illumination and recording, the system uses periodic pulsed illumination from the strobe light, synchronized with the drop ejection frequency. The camera captures images only during these brief illumination pulses. This periodic action reduces energy consumption compared to continuous high-speed recording while maintaining sufficient measurement precision for characterizing each individual drop.

Inventive Principle:
Principle #19Periodic action

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

This approach enables accurate and efficient detection of drop jitter, improving the quality of 3D printed objects by automatically adjusting printer parameters based on drop characteristics, reducing manual intervention and enhancing printing precision.

Implementation Method 1

A light source is disclosed. The light source is configured to illuminate the drop with a pulse of light

Methodology Applied
Scientific EffectStrobe light illumination: Light

Implementation Method 2

A camera is disclosed. The camera is configured to capture an image, video, or both of the drop

Methodology Applied
Scientific EffectPhotography: Photography

Implementation Method 3

an electrical current flows through a metal coil, which produces time-varying magnetic fields that induce eddy currents within a reservoir of liquid metal compositions. Coupling between magnetic and electric fields within the liquid metal results in Lorentz forces that cause drops of the liquid metal to be ejected

Methodology Applied
Scientific EffectMagnetohydrodynamic effect: Magnetohydrodynamic Effect

Implementation Method 4

produces time-varying magnetic fields that induce eddy currents within a reservoir of liquid metal compositions

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Implementation Method 5

Coupling between magnetic and electric fields within the liquid metal results in Lorentz forces that cause drops of the liquid metal to be ejected

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Data Source

PatentUS11945169B2System and method for characterizing liquid metal drops jetted from a 3D printer using a strobe light
Publication Date: 2024.04.02 XEROX CORP
  • US11945169B2 patent drawing
  • US11945169B2 patent drawing
  • US11945169B2 patent drawing

AI summary

A 3D printer includes a nozzle configured to jet a drop of liquid metal therethrough. The 3D printer also includes a light source configured to illuminate the drop with a pulse of light. A duration of the pulse of light is from about 0.0001 seconds to about 0.1 seconds. The 3D printer also includes a camera configured to capture an image, video, or both of the drop. The 3D printer also includes a computing system configured to detect the drop in the image, the video, or both. The computing system is also configured to characterize the drop after the drop is detected. Characterizing the drop includes determining a size of the drop, a location of the drop, or both in the image, the video, or both.