Optical Contact Control for Micro-Structural Fluid Ejectors

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Solution Overview

Problem

Existing conductive ink printing methods face challenges in maintaining alignment precision over large distances and accurately detecting contact and fluid flow faults, particularly due to stringent requirements for vertical displacement control and precise contact with the substrate.

Innovation Solution

A method involving a micro-structural fluid ejector with a tapering portion and an imaging system, where a camera captures digital images to detect edges and measure lengths to adjust the print head's position, and a pneumatic system is used to apply pressure and displace the print head laterally, allowing for real-time adjustment and fault detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If micro-structural fluid ejectors are used to achieve precise material deposition, then manufacturing precision is improved, but the complexity of detecting and adjusting contact to the substrate increases device complexity

Engineering Contradiction:
Improvematerial deposition precisionVSAvoidcontact detection and adjustment system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical contact detection and adjustment systems with optical detection methods. A light source illuminates the substrate surface, and sensors detect optical signals (such as reflected light intensity changes) to determine contact status, eliminating the need for mechanical switches or physical contact sensors.

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

Solution Approach 2:

The patent introduces an optical field as an intermediary between the fluid ejector and substrate. Light serves as a mediator to transmit information about contact status without requiring direct mechanical interaction, enabling non-contact detection and reducing system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If continuous monitoring of fluid ejector contact is implemented, then reliability is improved, but the use of energy increases due to continuous operation of detection systems

Engineering Contradiction:
Improvecontact detection reliabilityVSAvoiddetection system energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic or event-triggered detection instead of continuous monitoring. The detection system operates intermittently based on process stages or detected events (such as changes in fluid flow patterns), maintaining reliable contact detection while significantly reducing energy consumption compared to continuous operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The detection system utilizes the existing fluid flow and optical components already present in the deposition process. The same light source and optical paths used for process monitoring serve dual purposes for contact detection, eliminating the need for separate dedicated detection components and reducing overall energy requirements.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If real-time adjustment of ejector contact is implemented, then manufacturing precision is improved, but the speed of the deposition process decreases due to adjustment cycles

Engineering Contradiction:
Improvecontact precisionVSAvoiddeposition process speed
Core Design Contradiction:
Manufacturing precisionVSSpeed

Solution Approach 1:

The patent performs preliminary contact calibration and positioning before the main deposition process begins. Once contact is established and verified through optical detection, the system maintains stable operation without frequent adjustments, preserving high deposition speed while ensuring precision through advance setup.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback control system where optical sensors continuously monitor contact status and provide real-time information to the control system. The system automatically adjusts ejector position or deposition parameters based on detected variations, maintaining manufacturing precision without requiring manual intervention or process interruption.

Inventive Principle:
Principle #23Feedback

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 precise control of the print head's vertical displacement and detection of fluid flow faults, improving the accuracy and reliability of conductive ink printing over large areas by ensuring proper contact and fluid dispensing.

Implementation Method 1

An optical detection system may be used to detect contact of the micro-structural fluid ejector to the substrate

Methodology Applied
Scientific EffectOptical detection: Reflection

Implementation Method 2

A piezoelectric actuator may be used to adjust a position of the micro-structural fluid ejector

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3749526B1Methods of detecting and adjusting contact of a micro-structural fluid ejector to a substrate
Publication Date: 2023.02.15 XTPL SA
  • EP3749526B1 patent drawingFigure 1
  • EP3749526B1 patent drawingFigure 2
  • EP3749526B1 patent drawingFigure 3

AI summary

Methods are disclosed relating to the operation of a micro-structural fluid ejector in a fluid printing apparatus. The methods include providing an imaging system, capturing a digital image of the micro-structural fluid ejector and its surroundings, and pre-processing the digital image to detect edges. A method of detecting contact of a micro-structural fluid ejector to a substrate includes repeatedly lowering the print head and measuring the length of a detected edge until the currently measured length is determined to be longer than a previously measured length. A method of adjusting contact of a micro-structural fluid ejector to a substrate includes calculating a bending coefficient A of the micro-structural fluid ejector and lowering the print head toward the substrate if the bending coefficient A is less than a minimum threshold value Amin, raising the print head away from the substrate if the bending coefficient A is greater than a maximum threshold value Amax, and making no change to the vertical displacement of the print head if the bending coefficient A is in the range of Amin to Amax. A method of detecting a fault condition in fluid flow from a micro-structural fluid ejector onto a substrate includes analyzing the digital image to determine whether edges are present in a region of interest where fluid dispensed from the micro-structural fluid ejector should be present.