Self-Cleaning Appliance Surfaces With Dual Micro-Structures
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Solution Overview
Problem
Household appliances often struggle with cleanliness and hygiene due to the accumulation of dust, dirt, and microorganisms on their surfaces, especially on difficult-to-clean areas, leading to bad odors and the need for frequent and labor-intensive cleaning.
Innovation Solution
A household appliance with self-cleaning surfaces featuring dual micro-scale structures, comprising micro-pillars and micro-cells, where the micro-cell is located on top of the micro-pillar, and separated by micro-channels, creating a super-hydrophobic surface that reduces contact area and adhesion, allowing water droplets to easily remove dirt and contaminants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional smooth surfaces are used in household appliances, then manufacturing is simple and cost-effective, but dirt and microorganisms accumulate easily and cleaning requires significant effort
Solution Approach 1:
The surface is segmented into dual micro-scale structures consisting of micro-pillars and micro-cells, creating a hierarchical architecture that reduces contact area between water droplets and the surface. This segmentation enables the self-cleaning effect by minimizing adhesion forces between dirt particles and the surface.
Solution Approach 2:
The invention transitions from a conventional two-dimensional smooth surface to a three-dimensional hierarchical micro-structure with micro-pillars (height 3-5 times the micro-cell) and micro-cells. This dimensional transformation creates super-hydrophobicity with contact angles of 160° to 180°, enabling water droplets to roll off and carry away contaminants.
2Reliability
If smooth surfaces are used, then manufacturing is easy and economical, but hygiene deteriorates due to microorganism proliferation
Solution Approach 1:
The surface structure enables self-cleaning functionality where water droplets automatically remove dirt and microorganisms without human intervention. The hierarchical micro-structure causes water to form high-contact-angle droplets that roll off the surface, picking up contaminants and eliminating the need for manual cleaning operations.
Solution Approach 2:
The invention fundamentally changes the surface parameters by creating micro-scale structures with specific geometric relationships (micro-pillar height 3-5 times the micro-cell dimension). This parameter transformation alters the surface's interaction with water, achieving super-hydrophobicity that prevents microorganism adhesion and proliferation.
3Productivity
If dual micro-scale structures are created to achieve self-cleaning, then cleaning efficiency improves, but manufacturing complexity and cost increase
Solution Approach 1:
The invention replaces mechanical cleaning systems (brushes, sponges, manual scrubbing) with a passive physical-chemical surface structure. The dual micro-scale architecture inherently generates super-hydrophobicity, causing water droplets to automatically remove contaminants through adhesion forces, eliminating the need for mechanical cleaning intervention.
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 super-hydrophobic surface effectively prevents dirt and microorganisms from adhering, enabling easy cleaning and maintaining hygiene with reduced frequency and effort, while the manufacturing process using laser ablation is environmentally friendly and economically viable.
Implementation Method 1
Laser ablation is a form of micromachining applying high energy laser beams to remove the material from the surface of the solid substrate
Implementation Method 2
The surface of lotus leaves shows a double structure that reduces the contact area and adhesion force between droplet and surface significantly, causing the leaves to be hydrophobic and highly water-repellent
Implementation Method 3
If a water droplet rolls across a contaminated surface area the adhesion between the dirt particle, irrespective of its composition, and the droplet is higher than the adhesion between the particle and the surface
Data Source
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AI summary
A household appliance (18, 21) and a process for its manufacturing, with at least one self-cleaning surface (20, 33, 37) provided on a base material (16), wherein the self-cleaning surface (20, 33, 37) comprises a plurality of dual micro-scale structures (3), wherein a dual micro- scale structure (3) is formed by two single micro-scale structures, wherein one single micro-scale structure has a first geometry and one single micro-scale structure has a second geometry (2) and wherein the single micro-scale structure having the second geometry (2) is located on top of the single micro-scale structure having the first geometry, wherein the first geometry is a micro-pillar geometry and the second geometry is a microcell geometry (2).