Adhesion Testing Under Moisture and Oscillating Substrate Deformation
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Solution Overview
Problem
Existing methods and devices for testing the adhesion of transdermal therapeutic systems on human skin lack the ability to simulate actual load situations and ambient conditions, particularly during movement and moisture changes, leading to inadequate assessment of long-term adhesion.
Innovation Solution
A method and device using a dumbbell-shaped magnetic stirring rod to apply mechanical force from the underside of a planar substrate, simulating skin movements by oscillating deformation, combined with substrate moistening to mimic skin conditions, and visual or quantitative assessment of adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional adhesion testing methods are used, then the testing procedure is simple, but the test results do not accurately reflect actual skin conditions and movement loads
Solution Approach 1:
The patent creates a simplified model system that copies the essential characteristics of skin-adhesion interactions. The planar substrate with adhesive body replicates the skin-adhesive interface, allowing accurate adhesion assessment without requiring actual human skin testing. This copying approach maintains measurement precision while reducing device and ethical complexity.
Solution Approach 2:
The patent applies preliminary moistening to the substrate before adhesion testing to simulate the hydrated state of skin. This preliminary action ensures that the adhesion properties are measured under conditions that accurately reflect actual skin conditions, improving measurement precision without requiring complex environmental control systems during the actual test.
2Measurement precision
If gravitational forces are included in the test, then the test setup is simpler, but gravitational influences contaminate the adhesion measurement
Solution Approach 1:
The patent employs a magnetic stirring rod that applies oscillating forces counteracting gravitational influences on the adhesive body. By using magnetic actuation to create controlled oscillations, the system eliminates the confounding effect of gravity on adhesion measurements, achieving precise measurement of adhesive properties independent of gravitational force.
Solution Approach 2:
The patent replaces traditional mechanical loading methods with magnetic actuation. The magnetic stirring rod uses magnetic fields to apply controlled oscillating forces to the adhesive body, substituting complex mechanical force application systems with a simpler magnetic field-based actuation mechanism that more easily eliminates gravitational contamination.
3Reliability
If the substrate is kept dry, then the test procedure is simpler, but the test does not simulate actual skin conditions with moisture
Solution Approach 1:
The patent applies preliminary moistening to the substrate surface before applying the adhesive body and conducting the adhesion test. This single preliminary action adequately simulates the hydrated state of skin without requiring continuous moisture control systems, maintaining device simplicity while ensuring reliable test results that reflect actual skin conditions.
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
Provides a reproducible and informative test method that accurately assesses the adhesion of planar bodies on substrates, accounting for skin movements and moisture, reducing unwanted gravitational influences and improving the evaluation of adhesion properties.
Implementation Method 1
a mechanical force is exerted on the planar substrate by means of an element in the form of a dumbbell-shaped stirring rod
Implementation Method 2
the action of which reversibly deforms the planar substrate repeatedly or in an oscillating manner
Implementation Method 3
the dumbbell-shaped magnetic stirring rod rotates underneath the substrate while deforming the latter
Implementation Method 4
the planar substrate is moistened, advantageously fully to saturation or is impregnated
Data Source
AI summary
Disclosed are a method and device for testing the adhesion of an adhesive, planar body on a planar substrate, wherein the planar body is applied adhesively on the substrate, the substrate is moistened, and a mechanical force is exerted on the substrate by means of an element in the form of a dumbbell-shaped magnetic stirring rod acting on the side of the substrate facing away from the adhesively applied body, wherein the substrate is repeatedly reversibly deformed at least in parts of the adhesive region of the planar body by means of the exertion of force, and, after a period of time, exertion of the mechanical force is ended, and the remaining adhesion of the planar body is assessed in qualitative and/or quantitative terms.