Actuated Membrane Airflow for Sensor Response Time
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Solution Overview
Problem
Mobile devices with environmental sensors face long response times to changes in ambient conditions due to slow airflow and thermal mass, limiting their effectiveness in detecting temperature and humidity changes.
Innovation Solution
Incorporating an electrically actuated membrane, such as a speaker or microphone membrane, to increase airflow over environmental sensors, allowing the controller to actuate the membrane at inaudible frequencies to enhance airflow and reduce response time by equalizing air conditions with the ambient environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If environmental sensors are placed inside mobile device housing, then they are protected from environmental damage, but response time to detect ambient conditions deteriorates due to slow airflow and thermal mass
Solution Approach 1:
The patent uses a speaker membrane to generate mechanical vibrations that create airflow across the sensor surface. By actuating the speaker at specific frequencies, the membrane oscillates to pump air over the environmental sensor, significantly reducing response time while maintaining sensor protection within the housing.
Solution Approach 2:
The patent employs pneumatic principles by using the speaker as an air pump to force air flow through the housing. The speaker membrane's oscillation creates pressure differentials that drive air flow across the sensor, enabling rapid environmental detection while the sensor remains protected inside the sealed housing.
2Loss of time
If airflow over environmental sensor is increased using electrically actuated membrane, then response time improves, but device complexity increases due to additional actuation mechanisms
Solution Approach 1:
The patent applies multi-functionality by using the speaker membrane for both its traditional audio output function and as an air pumping mechanism for sensor cooling. The same electrically actuated membrane serves dual purposes: generating sound waves for audio playback and creating airflow for rapid environmental sensing, thereby avoiding additional complexity.
Solution Approach 2:
The speaker membrane serves itself by using its inherent oscillation capability to perform the additional function of air pumping. No separate actuation mechanism is required - the existing speaker coil and membrane structure are utilized to generate the necessary airflow, making the system self-sufficient and avoiding added complexity.
3Productivity
If speaker is actuated at resonant frequency of vent channel, then airflow efficiency is maximized, but audible noise is generated when resonant frequency is above 30 Hz
Solution Approach 1:
The patent changes the operating frequency parameter of the speaker to be at or near the resonant frequency of the vent channel, but specifically selects resonant frequencies below 30 Hz. This parameter adjustment maximizes airflow efficiency through resonance while simultaneously eliminating audible noise by operating in the infrasound range, resolving the contradiction between efficiency and noise.
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 approach significantly reduces the response time of environmental sensors to changes in ambient conditions, allowing for more rapid detection of temperature, humidity, and gas concentrations, improving the sensors' ability to accurately reflect ambient conditions.
Implementation Method 1
a piezo electric material or any component which deforms or deflects in response to an electric current being applied either directly or indirectly
Implementation Method 2
an electrically actuated membrane, such as a speaker or microphone membrane
Implementation Method 3
the actuation of the membrane may cause a relative increase in air flow over the environmental sensor compared to the air flow without the actuation
Implementation Method 4
the air in the vicinity of the sensor may be refreshed so that it may equalized to the conditions of the ambient environment more rapidly
Data Source
AI summary
A mobile device comprising an environmental sensor and an electrically actuated membrane is described. The electrically actuated membrane may increase the airflow over the environmental sensor which may improve the response of the sensor to changes in the ambient environment around the mobile device.