Bistable Mechanism Toothbrush for Force Feedback

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Solution Overview

Problem

Existing force-sensitive toothbrushes are bulky, unattractive, and expensive due to their multi-component designs, which has hindered their commercial availability despite the known issues of tooth erosion and gum recession from excessive brushing force.

Innovation Solution

A cost-effective, ergonomic force-sensitive toothbrush incorporating a bistable mechanism within the handle that alerts users to excessive brushing force through shape change, utilizing a principal beam and a secondary support beam that buckles or features a toothed clutch, molded into a single integral body using injection molding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple components are used to create a force-sensitive toothbrush, then the toothbrush can provide force feedback to users, but the toothbrush becomes bulky, expensive, and unattractive

Engineering Contradiction:

Improveforce feedback capabilityVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the force-sensitive mechanism directly into the toothbrush handle structure, combining the feedback mechanism with the handle body into a single integrated component. This eliminates the need for separate mechanical assemblies and reduces the number of parts while maintaining the force feedback function.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The toothbrush handle serves multiple functions: it provides structural support, contains the force-sensitive mechanism, and delivers tactile feedback to the user. By making the handle multi-functional, the patent eliminates the need for additional dedicated components for force sensing and feedback.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If multiple components are used in the force-sensitive toothbrush design, then force sensing capability is achieved, but manufacturing cost increases

Engineering Contradiction:

Improveforce sensing capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The force-sensitive mechanism is merged with the handle structure, allowing both components to be manufactured as a single integrated piece. This reduces assembly steps and component costs while maintaining force sensing capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The handle structure itself serves as the force-sensitive mechanism, using its own structural properties (such as flexing or bending) to detect and provide feedback on brushing force. This self-service approach eliminates the need for separate sensing components and reduces manufacturing complexity.

Inventive Principle:

Principle #25Self-service

3Reliability

If a force-sensitive mechanism is added to the toothbrush, then user feedback on brushing force is provided, but the toothbrush becomes less ergonomic

Engineering Contradiction:

Improveuser feedback capabilityVSAvoidergonomic design

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The force-sensitive mechanism is combined with the handle in a way that preserves the natural grip and handling characteristics. The mechanism is integrated into the handle's structural profile, ensuring it does not protrude or create uncomfortable areas during gripping.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The force-sensitive mechanism is localized to specific regions of the handle where it can effectively sense brushing force without interfering with the overall ergonomic shape. The handle maintains its comfortable grip profile in user-contact areas while incorporating the sensing function in strategically positioned regions.

Inventive Principle:

Principle #3Local quality

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 provides effective feedback to users through audible and tactile cues when excessive force is applied, preventing dental issues while maintaining a compact and affordable design.

Implementation Method 1

a secondary notched hinge buckling support beam located within the handle between the bristles and the gripping portion of the toothbrush

Methodology Applied

Scientific EffectBuckling:

Implementation Method 2

The mechanism can also automatically return to its original state when the brushing forces are lowered back down below the predetermined level

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS9289055B2Force sensitive toothbrush

Publication Date: 2016.03.22 SLOCUM JONATHAN T

AI summary

A force-sensitive toothbrush incorporates a bistable mechanism into the toothbrush handle. The mechanism can alert a user to excessive brushing force by changing shape in response to brushing forces exceeding a predetermined threshold. The mechanism can also automatically return to its original state when the brushing forces are lowered back down below the predetermined level. In one aspect, the mechanism may include a force-sensitive region having a principal beam and a secondary notched hinge buckling support beam located within the handle between the bristles and the gripping portion of the toothbrush. In another aspect, the force-sensitive region includes a principal beam and a secondary un-notched buckling support beam. In another aspect, the force-sensitive region includes a principal beam and a secondary support beam with a toothed clutch. These mechanisms can advantageously be molded into an integral toothbrush body using an injection molding operation.