Electroosmotic Pump for Hearing Aid Humidity Removal

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current hearing aids face challenges in effectively and efficiently removing humidity, leading to corrosion and functional defects due to the limitations of passive semi-permeable membranes, which result in slow humidity drainage and potential chemical reactions that damage internal components.

Innovation Solution

The integration of an electroosmotic pump with a semi-permeable membrane and electrode elements across the hearing aid casing to actively transport humidity out, utilizing an electric current to enhance the rate and efficiency of humidity removal, optimizing energy consumption and execution time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If passive semi-permeable membranes are used for humidity removal, then the hearing aid structure remains simple, but the humidity drainage rate is slow leading to corrosion and functional defects

Engineering Contradiction:
Improvehumidity drainage rateVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces passive mechanical diffusion-based semi-permeable membranes with an electroosmotic pump system that uses electrical fields to actively pump humidity out of the hearing aid. The electroosmotic pump comprises a porous substrate with ion-exchange groups and electrode elements that generate electroosmotic flow to rapidly transport liquid humidity through the membrane, achieving fast drainage without compromising device structure.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operating parameters by applying voltage to the electrode elements, which alters the physical state of the porous membrane from passive to active. When voltage is applied, the ion-exchange groups generate electroosmotic flow, dramatically increasing the humidity removal rate from slow passive diffusion to rapid active pumping, thus resolving the contradiction between simplicity and productivity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If faster humidity removal is achieved, then corrosion and damage to components are prevented, but energy consumption increases

Engineering Contradiction:
Improvecomponent protection from corrosionVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic or on-demand activation of the electroosmotic pump rather than continuous operation. The pump can be activated periodically to remove accumulated humidity or triggered by humidity sensors when threshold levels are reached, providing adequate component protection while minimizing energy consumption during normal dry periods.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The electroosmotic pump structure with ion-exchange groups in the porous substrate enables the system to actively manage its own humidity levels. The pump can be activated based on internal humidity conditions, allowing the hearing aid to self-regulate and protect its components without requiring constant external energy input or complex control systems.

Inventive Principle:
Principle #25Self-service

3Ease of manufacture

If passive membranes are used, then manufacturing remains simple, but chemical reactions occur that damage internal components

Engineering Contradiction:
Improveease of manufactureVSAvoidchemical reactions from humidity
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces passive mechanical membranes that allow slow humidity penetration with an electroosmotic pump system that actively pumps humidity out before it can cause chemical reactions. The electroosmotic mechanism using ion-exchange groups and electrical fields provides rapid humidity removal, preventing corrosion and chemical damage to electronic components while maintaining manufacturability through integrated membrane-electrode structures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If electroosmotic pump is integrated, then humidity removal efficiency increases, but device complexity increases

Engineering Contradiction:
Improvehumidity removal efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the porous membrane substrate with electrode elements and ion-exchange groups into an integrated electroosmotic pump unit. This combination eliminates the need for separate passive membrane components and complex humidity sensing systems, as the electroosmotic structure itself provides both the barrier and the active pumping mechanism, thereby increasing efficiency while managing device complexity through integration.

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

This solution enables rapid and complete removal of humidity, preventing damage to hearing aid components, extending their lifespan and reducing the risk of oxidation and corrosion, while maintaining energy efficiency and usability.

Implementation Method 1

at least one electroosmotic membrane, which has a first entry surface and a second exit surface, and is configured to transport liquid and/or vapor from a first entry surface to a second exit surface by applying a voltage difference across the membrane

Methodology Applied
Scientific EffectElectroosmosis: Electro-Osmosis

Data Source

PatentEP3406087B1Self-drying hearing aid and method for transporting humidity out of such hearing aid
Publication Date: 2020.09.23 SONOVA AG
  • EP3406087B1 patent drawingFigure 1
  • EP3406087B1 patent drawingFigure 2
  • EP3406087B1 patent drawingFigure 3A~3B

AI summary

This invention relates to a hearing aid (100) comprising at least one electro acoustic transducer (1, 1', 1*);a signal processing circuitry (2, 2AD, 2DA), configured to receive from the at least an electroacoustic transducer (1) an electrical input signal and/or to provide said at least an electroacoustic transducer (1', 1*) with an electrical output signal; and power supply means (4, 5) configured to provide power to the electroacoustic transducer (1, 1', 1*) and to said signal processing circuitry (2, 2AD, 2DA); wherein the hearing aid further comprises at least one electroosmotic pump (6, 6o, 6i) configured to transport liquid and/or vapor outside of the hearing aid (100), or away from a component thereof (1, 1', 1*, 8). The electroosmotic pump (6) comprises a porous intermediate layer (7i) and,on each side thereof, electrode elements (7p, 7n) which are connected to the power supply means (4, 5) so that transport of liquid and/or vapor is induced by an electric field applied between the electrode elements (7p, 7n) across said electroosmotic pump (6).The present invention also relates to a method of drying a wearable device, such as a hearing aid (100), by way of such an electroosmotic pump (6, 6o, 6i).