Microphase-Separated Coatings for Insect and Ice Repellency

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Solution Overview

Problem

Current coatings for aircraft and aerospace surfaces fail to effectively remove insect debris and ice accumulation, leading to increased drag, fuel consumption, and maintenance challenges, with existing solutions either being impractical, durable but non-functional, or requiring frequent reapplication.

Innovation Solution

A microphase-separated composition comprising chemically distinct solid materials with different surface energies and a selectively absorbed liquid, such as a freezing point depressant or lubricant, which enhances the coating's ability to repel debris and ice by creating a self-cleaning and anti-icing surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If superhydrophobic surfaces with high contact angles are used to repel water and oil, then water and oil repellency is improved, but these surfaces do not repel solid foreign matter or vapors of contaminants and lose function when scratched

Engineering Contradiction:
Improvewater and oil repellencyVSAvoiddurability against scratching and solid contaminant repulsion
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent combines superhydrophobic materials (for water/oil repellency) with sacrificial lubricant materials (for solid contaminant repulsion and scratch resistance) into a composite coating system. The lubricant material is interlayered with or embedded in the superhydrophobic material, creating a multi-functional coating that maintains water repellency while adding protection against solid contaminants and mechanical damage.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The sacrificial lubricant material acts as an intermediary between the superhydrophobic surface and solid contaminants. When scratches occur or solid contaminants impact the surface, the lubricant material is consumed preferentially, protecting the underlying superhydrophobic structure and maintaining its functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If enzyme-filled coatings are used to dissolve debris on the surface, then debris removal is improved, but enzymes are quickly depleted and cannot be refilled

Engineering Contradiction:
Improvedebris dissolution rateVSAvoidcoating lifespan
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The patent employs sacrificial lubricant materials that are intentionally designed to be consumed or depleted over time. These materials are relatively inexpensive and can be replenished by reapplying the coating, similar to disposable components that are replaced rather than maintained indefinitely.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The sacrificial lubricant material is designed to be discarded (consumed) during normal operation as it sacrifices itself to repel contaminants and protect the underlying structure. The coating system allows for periodic recovery through reapplication of the coating to restore the sacrificial layer.

Inventive Principle:
Principle #34Discarding and recovering

3Object-affected harmful factors

If mechanical scrapers and continuously released liquid layers are used to remove insect debris, then insect residue reduction is improved, but size and weight penalty increases

Engineering Contradiction:
Improveinsect residue reductionVSAvoidcoating system weight
Core Design Contradiction:
Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The patent creates a self-service coating system that automatically repels insect debris through the combined action of superhydrophobic properties and sacrificial lubricant materials. The coating self-regenerates by capillary wicking of lubricant from the bulk material to the surface, eliminating the need for external mechanical scrapers or continuous liquid supply systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts and eliminates the heavy mechanical components (scrapers, pumps, liquid supply systems) from the insect debris removal system, retaining only the essential functional properties in a lightweight coating formulation. The active ingredients (superhydrophobic materials and lubricants) are applied as thin films that provide protection without significant weight addition.

Inventive Principle:
Principle #2Taking out (Extraction)

4Ease of operation

If low-energy polymers are used for non-stick coatings, then release of adhering materials is improved, but they do not necessarily provide a lubricated surface to promote clearance of foreign substances

Engineering Contradiction:
Improverelease of adhering materialsVSAvoidclearance of foreign substances
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent merges two distinct functional materials into a single coating system: low-energy polymers (for non-stick properties and release of adhering materials) and sacrificial lubricant materials (for promoting clearance of foreign substances). The lubricant component provides a lubricated surface that facilitates the mechanical removal of contaminants, complementing the non-stick properties of the low-energy polymer.

Inventive Principle:
Principle #5Merging (Combining)

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 composition effectively reduces insect and ice adhesion, maintaining functionality and durability without the need for frequent reapplication, thereby improving fuel efficiency and reducing maintenance costs.

Implementation Method 1

the liquid is: (a) a freezing point depressant for water

Methodology Applied
Scientific EffectFreezing point depression: Freezing

Implementation Method 2

the liquid is: (b) (i) is a lubricant selected from the group consisting of fluorinated oils, fluorocarbon ether polymers of polyhexafluoropropylene, siloxanes, petroleum-derived oils, mineral oil, plant-derived oils, canola oil, soybean oil, and combinations thereof

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP3526295B1Bugphobic and icephobic compositions with liquid additives
Publication Date: 2021.08.04 HRL LAB
  • EP3526295B1 patent drawingFigure 1
  • EP3526295B1 patent drawingFigure 2
  • EP3526295B1 patent drawingFigure 3A

AI summary

Some variations provide a composition comprising: a first solid material and a second solid material that are chemically distinct and microphase-separated; and at least one liquid selectively absorbed into either of the first solid material or the second solid material. The first and second solid materials are preferably present as phase-separated regions of a copolymer, such as in a segmented copolymer (e.g., a urethane-urea copolymer). The liquid may be a freezing-point depressant for water. For example, the liquid may be selected from methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, or glycerol. The liquid may be a lubricant. For example, the liquid may be selected from fluorinated oils, siloxanes, petroleum-derived oils, mineral oil, or plant-derived oils. The liquid may consist of or include water. The liquid may be an electrolyte. For example, the liquid may be selected from poly(ethylene glycol), ionic liquids, dimethyl carbonate, diethyl carbonate, or methyl ethyl dicarbonate.