Engineered Skin-Contact Surface for Friction Reduction

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Solution Overview

Problem

Conventional devices that contact skin or external tissue, such as earphones, baby bottles, and breast pumps, often cause skin irritation and discomfort due to high friction, which existing surface structures fail to adequately address.

Innovation Solution

A surface with engineered features, including dome-shaped protrusions with specific geometric parameters such as a pitch of 100 microns or less and a height of 100 microns or less, designed to directly engage external tissue, providing reduced friction and improved comfort by optimizing the material's durometer and shape for low friction and skin compatibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a conventional smooth surface is used for skin contact, then the device structure is simple and easy to manufacture, but friction is high causing skin irritation and discomfort

Engineering Contradiction:
Improveskin irritationVSAvoidsurface structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The contacting portion is segmented into multiple discrete dome-shaped surface features arranged in a pattern, rather than a continuous smooth surface. This segmentation reduces the effective contact area with skin, minimizing irritation while maintaining structural manageability through repetitive geometric units

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The surface features are designed with specific local geometric properties (dome shape, 20-50 micron diameter, spaced 40-60 microns apart) that optimize the local interaction with skin. This localized engineering of surface properties reduces friction and irritation at the contact points while the overall structure remains relatively simple

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If a structured surface with surface features is used to reduce friction, then user comfort is improved, but manufacturing precision requirements increase

Engineering Contradiction:
ImprovefrictionVSAvoidsurface feature precision
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The surface features are designed with specific parameter ranges (dome diameter 20-50 microns, spacing 40-60 microns, height 10-30 microns) that balance friction reduction effectiveness with manufacturability. These parameter specifications provide clear manufacturing targets while allowing reasonable tolerances for production processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The dome-shaped (spheroidal) geometry of surface features is chosen because it is relatively simple to manufacture using standard molding or machining techniques compared to more complex geometries. The curved surface naturally reduces contact pressure points and friction while being compatible with conventional manufacturing methods

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Object-affected harmful factors

If the pitch between surface features is reduced to increase coverage, then friction reduction is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
ImprovefrictionVSAvoidsurface feature density
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The surface features are spaced at intervals (pitch of 40-60 microns) that provide sufficient friction reduction without requiring complete continuous coverage. This partial action approach achieves the necessary friction reduction while maintaining manufacturability and avoiding the complexity of densely packed or continuous surface structures

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP2804733B1Engineered surface for providing low friction and improved comfort on devices that contact the skin or other external tissue of the user
Publication Date: 2020.07.08 KONINKLIJKE PHILIPS NV
  • EP2804733B1 patent drawingFigure 1A~1B
  • EP2804733B1 patent drawingFigure 1C
  • EP2804733B1 patent drawingFigure 1D~1F

AI summary

An apparatus structured to contact external tissue, such as skin, of a user includes an elastomeric contacting portion that is structured to directly engage the external tissue. The contacting portion has an engineered surface (64A, 64B) that includes a plurality of non- random, predesigned surface features (70, 74B, 76B, 78B) designed to reduce friction and improve user comfort. In one implementation, the pitch (P) between each immediately adjacent pair of the surface features (70, 76B) is less than or equal to a predetermined maximum pitch value, and the height (H) of each of the surface features (70, 76B) is less than or equal to a predetermined maximum height value.