Flexible Substrate Pressure Sensor for Electric Toothbrush
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pressure-sensing systems in toothbrushes are often complex, costly, and inaccurate, making it difficult to implement a compact, simple, and inexpensive solution for detecting the optimal pressure applied to the bristle field during brushing.
Innovation Solution
A pressure-sensing toothbrush design that incorporates a contact arm into a substrate, where flexing of the substrate at a threshold amount moves the contact arm to contact a sensor, activating a signal element to indicate when the applied force reaches a predetermined threshold, using a substrate with a contact arm, sensor contact, power source, and signal element within the toothbrush body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional pressure-sensing system with spring, moment arm, and switch is used, then pressure detection function is achieved, but device complexity and cost increase significantly
Solution Approach 1:
The patent merges the substrate (PCB) with the pressure-sensing function by integrating a flexible substrate that acts as both the structural base and the pressure-sensitive element. The contact arm is formed directly from the substrate material, eliminating the need for separate spring and moment arm components. This consolidation reduces device complexity while maintaining pressure detection functionality.
Solution Approach 2:
The patent extracts and eliminates unnecessary components from the traditional pressure-sensing system. By removing the separate spring, moment arm, and switch mechanisms, and replacing them with a simplified flexible substrate and contact arm structure, the system achieves pressure detection with significantly reduced complexity and lower cost.
2Reliability
If a traditional pressure-sensing system is used, then pressure detection function is achieved, but manufacturing cost increases significantly
Solution Approach 1:
The patent combines multiple functions into a single flexible substrate structure that serves as both the circuit board and the pressure-sensing element. This integration reduces the number of parts that need to be manufactured, assembled, and quality-tested, thereby lowering overall manufacturing costs while maintaining reliable pressure detection.
Solution Approach 2:
The patent employs a simple flexible substrate structure that can be manufactured using cost-effective materials and processes. The simplified design with fewer components allows for more economical production methods, reducing the overall manufacturing cost of the toothbrush while maintaining adequate pressure sensing capability.
3Reliability
If a traditional pressure-sensing system is used, then pressure detection function is achieved, but measurement accuracy suffers
Solution Approach 1:
The patent applies local quality by creating a specific flexible region in the substrate with controlled mechanical properties. The contact arm is designed with specific flexibility characteristics that allow it to deflect predictably under applied pressure, enabling accurate threshold detection. The sensor contact is positioned at a specific location where the flexing motion produces the most reliable electrical connection change.
4Volume of moving object
If a compact pressure-sensing system is designed, then device size is reduced, but implementation difficulty increases
Solution Approach 1:
The patent integrates the pressure-sensing functionality directly into the existing substrate structure of the toothbrush handle. By forming the contact arm from the substrate itself and positioning the sensor contact on the same substrate, the design eliminates the need for separate housing or mounting structures, achieving compactness without increasing implementation difficulty.
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 solution provides a compact, cost-effective, and accurate method to alert users when excessive pressure is applied, ensuring optimal brushing pressure without adding significant complexity or cost to the toothbrush.
Implementation Method 1
a force on the head causes the substrate to flex from an unflexed state to a flexed state, which moves the contact surface toward the sensor contact
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A pressure sensor for a toothbrush. The pressure sensor includes a substrate, a contact arm in the substrate, a power source, a signal element, and a sensor contact. The sensor contact may be mounted to the substrate such that the contact arm is not in contact with the sensor contact when the substrate is not flexed. As a user applies pressure to a toothbrush head, the substrate can flex and move the contact arm toward the sensor contact. When a threshold force is applied to the toothbrush head, the contact arm can contact the sensor contact, completing a circuit between the power source, the sensor contact, and the signal element that activates the signal element. A second sensor contact can be mounted to the substrate opposite the first sensor contact. The second sensor contact can allow the signal element to indicate three different states to a user.