Shape Memory Alloy Hinge for Easier Foldable Device Unfolding
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Solution Overview
Problem
Foldable electronic devices require manual intervention to unfold due to the need for external force to overcome magnetic attraction, leading to user inconvenience and reduced usability.
Innovation Solution
Incorporation of a hinge structure with a shape memory alloy wire that adjusts magnetic module position using current-induced length changes, allowing for automatic unfolding without manual manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If magnets are used to maintain the folded state, then the device can be held securely in the folded position, but the user must apply external force to overcome the magnetic attraction to unfold the device
Solution Approach 1:
The magnetic module housing is made movable relative to the first housing through a wire driving unit, allowing the magnetic module to dynamically adjust its position. This enables the magnetic attraction force to be modulated during operation, facilitating easy unfolding while maintaining stable folding through dynamic force adjustment rather than fixed mechanical constraints
Solution Approach 2:
The invention changes the position parameter of the magnetic module by moving the magnetic module housing along the first direction using the wire driving unit. By altering the distance between magnetic modules, the magnetic attraction force is adjusted, enabling the device to transition from a high-force folded state to a low-force unfolded state without manual intervention
2Extent of automation
If a wire driving unit with shape memory alloy is used to move the magnetic module, then automatic unfolding is enabled, but the device complexity increases
Solution Approach 1:
The invention replaces traditional mechanical actuators (motors, gears, linkages) with a shape memory alloy-based wire driving unit. The shape memory alloy wire transforms electrical energy directly into mechanical motion through thermal actuation, eliminating complex mechanical transmission components while achieving automatic positioning of the magnetic module
Solution Approach 2:
The shape memory alloy wire changes its physical state (crystalline structure) in response to electrical current, transforming from an austenite phase to a martensite phase. This phase transition causes the wire to contract or expand, directly driving the magnetic module housing without intermediate mechanical components, thus reducing overall system complexity
3Ease of operation
If traditional actuators like motors are used to move the magnetic module, then positioning control is achieved, but the device size increases
Solution Approach 1:
The invention replaces bulky mechanical actuators with a compact shape memory alloy wire driving unit. The wire-based actuation mechanism occupies significantly less volume than traditional motors or solenoids while providing equivalent positioning capability for the magnetic module, enabling device miniaturization
Solution Approach 2:
The invention extracts and eliminates unnecessary intermediate mechanical components (gears, belts, linkages) from the actuation system, retaining only the essential shape memory alloy wire that directly converts electrical energy to mechanical displacement. This streamlined approach reduces the volume of the moving object while maintaining positioning functionality
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
Facilitates easy unfolding of foldable devices by reducing magnetic force, minimizing power consumption, and enabling device miniaturization compared to using actuators like motors.
Implementation Method 1
the wire includes a shape memory alloy so that a length in the first direction is deformable as current is supplied from the feeding unit
Implementation Method 2
the first elastic member is configured to be deformed in a direction opposite to a deformation direction of the wire
Data Source
AI summary
An electronic device includes a hinge structure, first and second housings, and a first magnetic module disposed at the first housing and including at least one magnetic body accommodated in a first magnetic body housing to which a wire driving unit is coupled so that the first magnetic body housing is movable, a feeding unit seated on the wire driving unit, a first elastic member coupled to the first magnetic body housing and to the wire driving unit, and a wire coupled to the feeding unit and to the first magnetic body housing. The wire includes a shape memory alloy and is deformable. The first elastic member is deformable in a direction opposite to a deformation direction of the wire. The feeding unit includes a second elastic member configured to be coupled to the wire to be deformed in the same direction as the deformation direction.