Inductive Sensor Assembly with Hydrophobic Potting Gel
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Solution Overview
Problem
Electronic components, such as those in bathing installations, are vulnerable to corrosion from moisture, and existing encapsulating materials may not adequately protect them in harsh environments.
Innovation Solution
A touch-sensitive sensor assembly with a housing structure made from dielectric plastic, incorporating a flexible metal domed spring structure and a resiliently deformable potting gel that is hydrophobic and resistant to moisture, allowing for flexible actuation while maintaining protection from corrosive environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional encapsulating materials are used to protect electronic components from moisture, then corrosion protection is provided, but the components lose flexibility and become rigid
Solution Approach 1:
The patent changes the physical parameters of the encapsulating material by using a gel formulation that maintains flexibility while providing protection. The gel's viscoelastic properties allow it to conform to component movements and thermal expansions without cracking, thus maintaining both protection and flexibility simultaneously
Solution Approach 2:
The patent employs a composite gel material that combines protective properties with flexible characteristics. This composite formulation integrates corrosion-resistant ingredients with flexible polymer matrices, creating a material that delivers both corrosion protection and mechanical flexibility
2Reliability
If rigid encapsulating materials are used to seal electronic components, then environmental sealing is achieved, but the sensor assembly cannot accommodate thermal expansion and contraction
Solution Approach 1:
The gel material's viscoelastic parameters enable it to accommodate thermal cycling. The material softens at elevated temperatures to absorb expansion stresses and maintains structural integrity at lower temperatures, providing thermal stability while preserving environmental sealing
Solution Approach 2:
The gel material provides beforehand cushioning by absorbing thermal expansion stresses before they can cause damage to the sealed components. The material's compliant nature anticipates and mitigates thermal shock effects, protecting the assembly during temperature transitions
3Reliability
If thick encapsulating material is used to protect components, then corrosion protection is improved, but the device size increases
Solution Approach 1:
The gel material's unique rheological parameters allow it to provide superior corrosion protection at reduced thickness. The material's ability to conform to surface irregularities and self-heal minor defects enables effective sealing with thinner applications compared to traditional rigid encapsulants
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 solution effectively protects electronic components from moisture-induced corrosion while enabling sensitive touch-based control systems in bathing installations, ensuring reliable operation and user safety.
Implementation Method 1
a resiliently deformable potting gel that is hydrophobic and resistant to moisture
Implementation Method 2
The circuit board includes an inductive sensor area
Data Source
AI summary
An exemplary embodiment of an inductive electrical sensor assembly includes a hollow housing structure defining an open space within the housing structure and a circuit board mounted in the open space. The circuit board includes an inductive sense area. A flexible metal domed spring structure is mounted over the inductive sensor area. A stem portion extends from a actuator area of the housing structure and having a distal end disposed adjacent to or in contact with the spring structure. The domed spring structure is adapted to be flexed toward the inductive sensor area by force exerted by the stem portion when a user exerts force on the actuator area, the flexing of the domed spring structure resulting in a change of inductance of the inductive sensor area which may be sensed to indicate an actuator push. An exemplary embodiment of the sensor assembly may include a resiliently deformable potting material substantially filling open spaces in the hollow housing structure between the top surface and the circuit board, and an open space below the circuit board, enabling flexure of the domed spring structure while providing environmental protection.