Waterproof MEMS Sensor with Air-Permeable Cap and Water Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing waterproofing solutions for environmental sensors in portable devices, such as smartphones and smartwatches, are inadequate as they can lead to device degradation and misreading due to exposure to environmental aggressors like water, oil, and dust, causing port occlusion and temperature coefficient offset issues.
Innovation Solution
A waterproofed MEMS-based environmental sensor with an air-permeable cap structure and capacitive elements that detect water and oil presence, along with strain isolation and self-heating capabilities to mitigate these issues, eliminating the need for sensor gel and ensuring reliable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a sealed enclosure is used to waterproof environmental sensors, then water and oil protection is improved, but environmental interaction capability deteriorates
Solution Approach 1:
The patent employs a porous gel structure that allows selective passage of environmental molecules while blocking larger water and oil molecules. The porous configuration enables gas exchange and environmental sensing capability while maintaining waterproofing, thus resolving the contradiction between protection and environmental interaction.
Solution Approach 2:
The patent uses a flexible gel-based sealing layer that can deform to accommodate environmental variations while maintaining a waterproof barrier. This flexible membrane structure allows the sensor to remain protected from water and oil while still enabling necessary environmental interactions through its porous properties.
2Object-affected harmful factors
If sensor gel is used for waterproofing, then water protection is improved, but temperature coefficient offset stability deteriorates
Solution Approach 1:
The patent modifies the physical and chemical parameters of the gel structure, specifically its porosity and composition, to reduce temperature sensitivity. By controlling the gel's physical state and molecular structure, the temperature coefficient offset is minimized while maintaining waterproofing effectiveness.
Solution Approach 2:
The patent employs composite material structures combining gel with other materials having complementary properties. This composite approach allows the system to achieve both waterproofing and temperature stability by leveraging the strengths of each material while compensating for their individual weaknesses.
3Object-affected harmful factors
If gel-based sensors are used, then waterproofing is achieved, but strain induced effects increase
Solution Approach 1:
The patent segments the sensor structure into distinct functional layers, separating the waterproofing function from the sensing function. This segmentation allows the gel-based waterproofing layer to be optimized for protection while the sensing elements are positioned to minimize exposure to strain induced effects.
Solution Approach 2:
The patent introduces intermediary structures between the gel-based waterproofing layer and the sensing elements. These intermediary components act as mechanical buffers that decouple the waterproofing function from the sensing function, reducing strain transmission to the sensor while maintaining effective waterproofing.
4Measurement precision
If environmental sensors are exposed to the environment, then sensing accuracy is improved, but device reliability deteriorates
Solution Approach 1:
The porous gel structure enables selective environmental interaction while maintaining protection. The porous configuration allows accurate sensing of environmental parameters through molecular diffusion while the overall structure prevents water and oil ingress, thus achieving both accuracy and reliability.
Solution Approach 2:
The patent incorporates feedback mechanisms that monitor environmental conditions and adjust sensor operation accordingly. This feedback system allows the sensor to maintain accuracy under varying environmental conditions while protecting against degradation, thereby improving reliability through adaptive operation.
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 prevents device degradation and misreading by detecting and addressing water and oil exposure, maintaining sensor accuracy and reliability over the product lifetime.
Implementation Method 1
capacitive elements that detect water and oil presence
Implementation Method 2
capacitive elements that detect water and oil presence
Implementation Method 3
self-heating capabilities to mitigate these issues
Data Source
AI summary
A waterproofed environmental sensing device with water detection provisions includes an environmental sensor to sense one or more environmental properties. The device further includes an electronic integrated circuit implemented on a substrate and coupled to the environmental sensor via a wire bonding. An air-permeable cap structure is formed over the environmental sensor, and a protective layer is formed over the wire bonding to protect the wire bonding against damage.