Contact Angle Measurement Apparatus Drop Dosing

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Solution Overview

Problem

Existing contact angle measurement apparatuses are slow and cumbersome, requiring manual needle movement and multiple syringe-type drop dosing devices for measuring wettability, which complicates the process and reduces speed and accuracy, especially when determining surface free energy with multiple liquids.

Innovation Solution

A contact angle measurement apparatus with a liquid reservoir arrangement, drop dosing devices connected to a compressed gas system, and a controller for precise drop application and image recording, allowing for simultaneous application and measurement of multiple drops without needle movement, enabling faster and more accurate wettability assessment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a syringe type drop dosing device is used to transfer drops from needle tip to surface, then the apparatus can apply drops to surfaces, but the process becomes slow and requires manual needle movement and positioning

Engineering Contradiction:
Improvedrop application speedVSAvoidmanual needle movement complexity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The invention extracts the drop from the needle tip and places it directly onto the surface without requiring the needle to contact or closely approach the surface. This is achieved by allowing the drop to fall freely from the needle tip under gravity, eliminating the need for precise manual positioning and transfer operations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The manual mechanical operation of moving and positioning the needle is replaced by a automated system where the drop is dispensed and falls to the surface automatically. The controller manages the drop application process, substituting manual mechanical manipulation with an automated dispensing mechanism.

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

2Adaptability or versatility

If multiple syringe type drop dosing devices are provided to measure wettability with different liquids, then multiple liquids can be tested, but the device becomes bulky and drops cannot be placed close enough for single image recording

Engineering Contradiction:
Improvecapability to measure with multiple liquidsVSAvoidnumber of drop dosing devices
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention makes a single drop dosing device universal by enabling it to handle multiple different liquids through a replaceable liquid reservoir system. The same dosing device can be used with different liquids by simply changing the reservoir contents, eliminating the need for multiple dedicated devices.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention transitions from having multiple devices arranged in space (horizontal dimension) to having a single device with multiple liquid options (vertical dimension of liquid selection). This allows multiple liquids to be managed through a hierarchical structure rather than parallel devices.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If manual transfer of drops from needle to surface is used, then drop application is possible, but contamination between liquids occurs and measurement accuracy decreases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidliquid contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts the drop from the needle tip at a distance and allows it to fall freely onto the surface, preventing contact between the needle and surface. This eliminates the contamination risk that arises from needle-surface contact or close proximity during manual transfer operations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces air as an intermediary medium through which the drop travels from the needle tip to the surface. By allowing the drop to fall through air rather than requiring direct contact or close proximity to the surface, contamination is prevented while maintaining measurement accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If syringe type drop dosing devices are used, then drops can be applied, but the process is slow and requires careful positioning to avoid needle contact with surface

Engineering Contradiction:
Improvemeasurement speedVSAvoidavoidance of needle contact
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The invention extracts the drop application process from the constraint of needle proximity to the surface. By allowing the drop to fall freely from the needle tip without requiring the needle to be positioned close to or contact the surface, the process becomes faster and more reliable.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of moving the needle close to the surface and carefully transferring the drop (conventional approach), the invention inverts the approach by keeping the needle at a distance and allowing the drop to fall to the surface. This reverses the traditional sequence and spatial relationship, improving both speed and reliability.

Inventive Principle:
Principle #13The other way round (Inversion)

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 apparatus facilitates faster and more precise contact angle measurements, reduces contamination risks, and allows for the use of liquids with varying viscosities, providing reproducible results and improved ease of use with a compact, mobile design.

Implementation Method 1

a liquid pressurizing system, on which the drop dosing devices rely for driving liquid out of their respective outlet onto the surface, and which is adapted to pressurize liquid from the liquid reservoir arrangement

Methodology Applied
Scientific EffectGas pressure: Pressure Increase

Data Source

PatentEP2899528B2Contact angle measurement apparatus
Publication Date: 2023.05.17 KRUSS
  • EP2899528B2 patent drawingFigure 1
  • EP2899528B2 patent drawingFigure 2
  • EP2899528B2 patent drawingFigure 3

AI summary

The present application relates to a contact angle measurement apparatus comprising a liquid reservoir arrangement (35), at least one drop dosing device (30) in fluid communication with the liquid reservoir arrangement (35) and adapted for applying a drop (8) of a liquid stored in the liquid reservoir arrangement (35) onto a surface (6) of a sample body (7), an illuminating device (20) adapted for illuminating each drop (8) applied by the at least one drop dosing device (30) and disposed on the surface (6) from a first side, and an image recording device (10) adapted for recording an image of each applied drop (8) disposed on the surface (6) in side view from a second side opposite the first side. Each drop dosing device (30) comprises a liquid line (31), which comprises an outlet (32) and a valve (38), and which is adapted to guide a liquid stored in the liquid reservoir arrangement (35) towards the outlet (32) and out of the outlet (32) onto the surface (6). The apparatus further comprises a liquid pressurizing system (37) adapted to pressurize liquid from the liquid reservoir arrangement (35), and a controller (39) connected to the valve (38) of each drop dosing device (30) and to the liquid pressurizing system (37) and adapted to control the operation of the liquid pressurizing system (37) and, for each drop dosing device (30), opening and closing of the respective valve (38) to apply a drop (8) of the respective liquid from the respective liquid line (31) to the surface (6) in a jet of pressurized liquid, wherein for each drop dosing device (30) the controller (39) and the valve (38) are adapted such that the jet applies the liquid to the surface (6) with a flow rate of 45 µl/s or less.