Bi-stable Electromagnetic Actuator for Energy-Efficient Tactile Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electromagnetic actuators for tactile displays are expensive, bulky, and lack true localized feedback, making them inaccessible to the visually impaired and blind populations, and they consume energy to maintain the 'on' position, which is not portable or economical.
Innovation Solution
An electromagnetic actuator with a moving armature, a permanent magnet arrangement, and a lobed excitation coil that allows for miniaturization, energy-efficient operation, and bistability, where the armature adheres to a ferromagnetic surface without continuous power consumption, enabling localized and perceivable tactile feedback without energy consumption in the 'on' position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electromagnetic or piezoelectric technologies are used to move needles perpendicularly to provide localized tactile feedback, then truly localized feedback is achieved, but the actuation systems become heavy, bulky, and expensive
Solution Approach 1:
The patent merges the permanent magnet and armature into a single integrated moving assembly, eliminating the need for separate electromagnetic coils at each actuator location. This combination reduces component count and system weight while maintaining localized feedback capability through the magnetic coupling between the moving armature and stationary ferromagnetic surface.
Solution Approach 2:
The patent employs periodic electromagnetic actuation to switch between two stable states (raised and lowered positions). By using pulsed electromagnetic fields rather than continuous power, the system achieves localized tactile feedback with minimal energy consumption and reduced thermal effects, avoiding the need for heavy continuous power supply infrastructure.
2Measurement precision
If electromagnetic actuators are used to provide localized tactile feedback, then truly localized feedback is achieved, but the systems become bulky and expensive
Solution Approach 1:
The patent merges the permanent magnet and armature into a single integrated moving assembly, eliminating the need for separate electromagnetic coils at each actuator location. This combination reduces component count and system complexity while maintaining localized feedback capability through the magnetic coupling between the moving armature and stationary ferromagnetic surface.
Solution Approach 2:
The permanent magnet arrangement generates its own magnetic field without requiring external power during the raised state maintenance. The system serves itself by using the permanent magnet's inherent magnetic properties to maintain the tactile element in the raised position, eliminating the need for continuous power supply and complex control circuitry.
3Reliability
If continuous power is supplied to maintain the 'on' position of tactile actuators, then the tactile feedback is maintained, but energy consumption increases
Solution Approach 1:
The patent employs periodic electromagnetic actuation to switch between two stable states (raised and lowered positions). By using pulsed electromagnetic fields rather than continuous power, the system achieves tactile feedback maintenance with minimal energy consumption. The electromagnetic field is applied only during state transitions, not continuously.
Solution Approach 2:
The permanent magnet arrangement generates its own magnetic field without requiring external power during the raised state maintenance. The system serves itself by using the permanent magnet's inherent magnetic properties to maintain the tactile element in the raised position, eliminating the need for continuous power supply.
4Adaptability or versatility
If multiple individually assembled components are used in tactile display actuators, then functional requirements are met, but the per-item cost increases linearly with the number of needles
Solution Approach 1:
The patent merges the permanent magnet and armature into a single integrated moving assembly that can be manufactured as one piece using injection molding or similar processes. This integration eliminates the need for precise assembly of multiple components for each actuator, reducing labor costs and enabling batch production.
Solution Approach 2:
The patent changes the manufacturing approach from individual assembly to batch processing using injection molding. By transforming the production method and enabling mass production of integrated actuator units, the cost per item decreases significantly while maintaining functional requirements.
5Area of stationary object
If large area tactile display solutions are implemented, then sufficient graphic information can be displayed, but the weight and bulk make the system non-portable
Solution Approach 1:
The patent merges the permanent magnet and armature into a single integrated moving assembly, eliminating heavy electromagnetic coils at each actuator location. This integration significantly reduces the weight per actuator, enabling large area tactile displays to be implemented in portable devices.
Solution Approach 2:
The patent employs periodic electromagnetic actuation instead of continuous power supply, reducing the power supply system weight. By using pulsed fields and permanent magnets for state maintenance, the battery and power management components can be smaller, enabling portability even for large area displays.
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 a miniaturized, energy-efficient, and cost-effective tactile display with true localized feedback, allowing for perceivable tactile patterns without continuous energy use, suitable for portable devices, and reducing interference between adjacent actuators.
Implementation Method 1
Bi-stable actuator based on electromagnetic attraction
Implementation Method 2
a surface of ferromagnetic material, said permanent magnet arrangement being axially interposed between the surface made of ferromagnetic material and the excitation coil arrangement
Implementation Method 3
an excitation coil arrangement arranged coaxially with the pin, said coil arrangement being suppliable with a current to cause the moving armature to move
Data Source
AI summary
An electromagnetic actuator comprising a moving armature (41) comprising a pin (43) and a permanent magnet arrangement (45) arranged coaxially with the pin (43) and secured to it, and an excitation coil arrangement (42) arranged coaxially with the pin (43). The coil arrangement (42) is suppliable with a current to cause a movement of the movable armature (41). The actuator further comprises a surface (51) of ferromagnetic material. The permanent magnet arrangement (45) is axially interposed between the surface (51) of ferromagnetic material and the excitation coil arrangement (42). The permanent magnet arrangement (45) comprises a plurality of permanent magnet regions (45a) arranged around the pin (43) of the moving armature (41), wherein each permanent magnet region (45a) has a polarity opposite to the polarities of the permanent magnet regions (45a) angularly adjacent thereto. The excitation coil arrangement (42) comprises a coil having a lobed shape.