SMA Earbud Shape Adaptation for Stable Fit and Acoustic Sealing

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Solution Overview

Problem

Existing headsets struggle to provide comfortable and stable fit for users with varying ear shapes due to the inability to adapt to individual ear canal dimensions, leading to issues such as pressure, poor stability, and acoustic leakage.

Innovation Solution

Incorporation of a Shape Memory Alloy (SMA) component in the earbud and earmuff components that deform in response to temperature changes, allowing the headset to automatically adjust to the user's ear shape and size, enhancing comfort and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a nozzle is disposed inside a duct to supply cooling air to a brake disc, then the brake disc can be cooled effectively, but the nozzle may be damaged by debris flowing through the duct

Engineering Contradiction:
Improvecooling effectivenessVSAvoiddebris damage to nozzle
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A protective cage is introduced as an intermediary structure between the debris flow and the nozzle. The cage allows cooling air to pass through to the brake disc while blocking debris from reaching and damaging the nozzle, thus protecting the nozzle without compromising cooling effectiveness

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The duct structure is segmented into a protected region (where the nozzle is located) and an unprotected region (where debris flows). The protective cage creates a physical separation that segments the flow paths, allowing cooling air to reach the brake disc while preventing debris from accessing the nozzle

Inventive Principle:
Principle #1Segmentation

2Productivity

If the nozzle is positioned inside the duct, then cooling air can be delivered directly to the brake disc, but the nozzle structure becomes vulnerable to debris impact

Engineering Contradiction:
Improvecooling efficiencyVSAvoidnozzle durability
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The protective cage acts as a mediator that preserves the direct cooling path from nozzle to brake disc while simultaneously providing structural protection. The cage maintains cooling efficiency by allowing unrestricted air flow to the brake disc surface while protecting nozzle strength by blocking debris impact

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If a protective structure is added around the nozzle, then the nozzle is protected from debris, but the device complexity increases

Engineering Contradiction:
Improvedebris protectionVSAvoidstructural complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The protective cage is constructed as a thin-walled mesh or grid structure that provides effective debris protection while minimizing structural complexity. The cage uses simple geometric patterns (such as rectangular or circular openings) that are easy to manufacture and integrate into the existing duct system, avoiding complex mechanical components

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The protective structure is segmented into simple modular units (cage sections) that can be easily manufactured and assembled. This segmentation allows the protective function to be achieved through repeated simple geometric patterns rather than complex monolithic structures, reducing overall device complexity

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4280621B1Earphone, earphone assembly and related method
Publication Date: 2026.05.20 HUAWEI TECH CO LTD
  • EP4280621B1 patent drawingFigure 1~2
  • EP4280621B1 patent drawingFigure 3
  • EP4280621B1 patent drawingFigure 4

AI summary

This application discloses a headset, where the headset includes an ear housing and an earbud fastened to the ear housing, the earbud includes an earbud body and an SMA component embedded in the earbud body, and the earbud can automatically adjust a shape to adapt to a wearing environment. This application further discloses another headset, where the headset includes a headband and earmuffs connected to the headband, the earmuff includes an ear housing, an earpad fastened to the ear housing, and an SMA component embedded in the earpad, and the earpad can automatically adjust a shape to adapt to a wearing environment. The headset has high wearing comfort. This application further discloses a headset assembly including the foregoing headset and a related method.