Optical Relative Humidity Sensor Using Refractive Index Changes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic devices lack effective relative humidity sensing capabilities, which are essential for various applications such as fitness tracking, weather sensing, and environmental monitoring.
Innovation Solution
Incorporating a relative humidity sensor within the electronic device's housing, which includes a light emitter, a relative humidity-sensitive layer, and a light detector. The sensor measures relative humidity by detecting changes in light behavior as it passes through the sensitive layer, using methods such as interferometry, light scattering by nanoparticles, polarization changes, or sound wave generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a relative humidity sensor is added to the electronic device, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent combines the light emitter, relative humidity-sensitive layer, and light detector into a single integrated sensor assembly that can be incorporated as one unit into the electronic device housing, reducing the complexity of assembling multiple separate components while achieving accurate relative humidity measurement
Solution Approach 2:
The patent uses light as an intermediary to measure relative humidity. The light emitter emits light that passes through the humidity-sensitive layer, and the light detector detects changes in the light properties caused by humidity variations, enabling indirect measurement without direct contact with moisture
2Measurement precision
If an opening is provided in the housing for the sensor, then measurement precision is improved, but protection against environmental factors deteriorates
Solution Approach 1:
The patent applies a relative humidity-sensitive layer with specific local properties (such as refractive index changes) at the sensor interface, allowing the sensor to detect humidity changes without requiring direct exposure of electronic components to moisture. The sensitive layer is positioned at the opening interface to provide both detection capability and environmental protection
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
Enables accurate and reliable relative humidity measurements, enhancing the device's functionality in various applications and providing users with valuable environmental data.
Implementation Method 1
The relative humidity-sensitive layer may have at least one property, such as refractive index, that changes in response to relative humidity changes
Implementation Method 2
the light may be scattered by plasmonic nanoparticles in a relative humidity-sensitive material to determine the relative humidity
Implementation Method 3
polarized light may pass through the relative humidity-sensitive layer and measured to determine the relative humidity
Data Source
AI summary
An electronic device may include a housing and relative humidity sensor in the housing. The relative humidity sensor may include a relative humidity-sensitive layer, a light emitter that emits light into the relative humidity-sensitive layer, and a light detector that detects light that has passed through the relative humidity-sensitive layer. The relative humidity may be determined based on the detected light. For example, the light may be measured interferometrically to determine a path length of the light to determine the relative humidity. Alternatively, the light may be scattered by plasmonic nanoparticles in a relative humidity-sensitive material to determine the relative humidity. As other examples, polarized light may pass through the relative humidity-sensitive layer and measured to determine the relative humidity, or light may be used to form sound waves that may be measured to determine the relative humidity. In this way, a light-based relative humidity-sensor may make relative humidity measurements.