Wearable Button Assembly With Force Sensing Through a Sealed Sidewall
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pushbutton assemblies in wearable devices compromise the ability to seal the interior, as they require direct engagement with internal components, making it difficult to maintain a sealed state while allowing user interaction.
Innovation Solution
A control button assembly with a snap dome positioned between the contact head and the sidewall of the housing, generating an activation force detectable by a force sensor without extending into the interior, ensuring the device remains sealed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pushbutton assembly directly engages with the printed circuit board and force sensor, then accurate user interaction is achieved, but the ability to seal the interior of the device is reduced
Solution Approach 1:
The device is divided into two separate compartments: an exterior cavity housing the control button assembly and an interior cavity housing the force sensor and controller. The sidewall acts as a sealed barrier between these compartments, allowing the button assembly to be segmented from the internal electronics while maintaining functional connection through the force transmission mechanism.
Solution Approach 2:
The sidewall serves as an intermediary element that transmits force from the button assembly to the force sensor without requiring direct physical connection. This mediator allows the button to remain in the exterior cavity while still enabling accurate force detection by the sensor in the interior cavity, thus maintaining both sealing and interaction accuracy.
2Reliability
If the control button assembly does not extend through the housing into the interior, then the device can maintain a sealed state, but direct engagement with internal components is prevented
Solution Approach 1:
The direct mechanical connection between the button and internal components is replaced with a force transmission system. The button assembly transmits mechanical force through the sidewall to the force sensor, which converts it into an electrical signal. This substitution eliminates the need for the button to physically penetrate the housing while maintaining operational functionality.
Solution Approach 2:
The system changes the parameter of physical connection to functional connection. Instead of requiring physical contact between the button and internal components, the system uses force transmission through the housing material, changing the mode of interaction from direct mechanical engagement to indirect force sensing.
3Measurement precision
If a snap dome is positioned between the contact head and sidewall to generate activation force, then user interaction accuracy is improved, but the complexity of the button assembly increases
Solution Approach 1:
The snap dome utilizes a phase transition or state change in its mechanical structure - transitioning from a compressed state to a snapped-back state. This phase transition provides a distinct, detectable activation force that improves detection accuracy while the dome's elastic properties simplify the overall assembly compared to more complex mechanical switches.
Solution Approach 2:
The snap dome is a self-actuating component that automatically generates the activation force signal when pressed. It self-regulates the force transmission to the force sensor, eliminating the need for additional mechanical linkages or adjustment mechanisms, thus improving detection accuracy without proportionally increasing complexity.
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 allows for accurate and consistent user interaction while maintaining the device's sealed state, enhancing durability and reliability against environmental challenges.
Implementation Method 1
The snap dome is configured to selectively generate an activation force sufficient to travel through the sidewall and that is detectable by the force sensor
Data Source
AI summary
A wearable electronic device comprising a housing. The device additionally includes a force sensor enclosed within an interior of the housing and positioned adjacent to or engaged with an interior surface of the housing. The device further includes a control button assembly engaged with the housing. A proximal end of the control button assembly comprises a contact head. A distal end of the control button assembly comprises a button head that is moveable with respect to the housing. The housing comprises a sidewall, and the sidewall entirely separates the control button assembly from the force sensor. The control button assembly further comprises a snap dome positioned between the contact head and the sidewall of the housing. The snap dome is configured to selectively generate an activation force sufficient to travel through the sidewall and that is detectable by the force sensor.