Micro Relay Switches with Magnetic Latching for High-Power Miniaturization
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Solution Overview
Problem
Current relay switches, including macro-machined and micro electro-mechanical systems, are inadequate for high power applications due to limitations in miniaturization, integration, and energy efficiency, particularly in areas like solar panel routing, smart power measuring, and industrial lighting, where they fail to handle high voltage and current effectively without being fragile or requiring excessive power for actuation.
Innovation Solution
The development of electromagnetically actuated latched micro relay switches that can transmit up to 50 W of power and carry 10 A of current within a volume of less than 100 mm3, utilizing printed circuit boards and laminates to create rugged, conductive contacts with low voltage actuation and zero-power latching, enabling efficient high-power switching without external power requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If traditional macro-machined relays are used for high power applications, then they can handle high voltage and current, but they are difficult to fit in small packages (3000 mm3 or smaller)
Solution Approach 1:
The patent replaces traditional mechanical relay components (macro-machined contacts, mechanical springs) with microelectromechanical systems (MEMS) technology. The MEMS switch uses electrostatic actuation to control micro-scale contacts, enabling high power handling in a miniaturized package. The mechanical relay structure is substituted with a micro-fabricated device that uses electric field actuation instead of traditional electromagnetic coils and mechanical movement.
Solution Approach 2:
The patent transitions from two-dimensional planar contacts to three-dimensional vertically stacked contact structures. Multiple contact pairs are arranged in vertical layers, allowing high power handling capability to be achieved within a compact footprint. This vertical integration enables the device to fit in packages of 3000 mm3 or smaller while maintaining the ability to handle high voltage and current through multiple parallel contact paths.
2Volume of moving object
If electrostatic actuation is used in micro electro-mechanical switches, then the device can be miniaturized, but it cannot handle high power applications due to power coupling across small gaps and self-charging effects
Solution Approach 1:
The patent incorporates magnetic materials and damping structures during the micro-fabrication process before the device is assembled and operated. Magnetic latching elements are pre-positioned to provide immediate magnetic attraction when contacts close, preventing arcing and self-charging effects. Damping materials are pre-integrated to suppress contact bounce and reduce electromagnetic interference, enabling the miniaturized device to handle high power applications reliably.
Solution Approach 2:
The patent introduces magnetic fields as an intermediary mechanism to assist contact closure and maintain contact stability. Magnetic materials are embedded in the contact structure to provide attractive force that supplements the electrostatic actuation, ensuring reliable contact closure even at high power levels. This magnetic intermediary prevents power coupling across gaps and eliminates self-charging effects by maintaining firm contact pressure.
3Reliability
If traditional coil winding and contact switch assembly are used, then reliable industrial solutions are achieved, but further miniaturization is intrinsically limited
Solution Approach 1:
The patent merges multiple discrete components (coil, contacts, spring, housing) into a single integrated microelectromechanical device. The MEMS structure combines the actuation mechanism, contact elements, and supporting structures into one monolithic micro-fabricated component. This integration eliminates the need for traditional coil winding and separate assembly, achieving reliable industrial performance in a miniaturized form factor that can fit in packages of 3000 mm3 or smaller.
Solution Approach 2:
The patent changes the fundamental operating parameters of the relay by transitioning from electromagnetic actuation (requiring relatively high current through coils) to electrostatic actuation (using low voltage to create electric fields). This parameter change enables miniaturization because electrostatic forces can be generated at micro-scale dimensions without requiring large coils or high currents. The contact closure force is achieved through electric field attraction rather than electromagnetic induction, allowing the device to be scaled down while maintaining reliability.
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
These micro relay switches provide high power handling, embeddable small form factor, low insertion loss, high isolation, and zero-power latching, outperforming existing solutions in key features, especially in high-power applications like automotive and industrial lighting control.
Implementation Method 1
These small sized devices employ an electromagnetic actuation component that directs electric current through another contact in the 'on' state, or provides an open circuit in the 'off' state
Implementation Method 2
If the tethered magnet is pulled close enough to the bottom region, a magnetic material in a laminate layer, such as a thin layer of nickel, will hold the magnet down, thus latching it into the 'on' state
Data Source
AI summary
Micro-electromagnetically actuated latched miniature relay switches formed from laminate layers comprising a spring and magnet, electromagnetic coils, magnetic latching material, and transmission line with contacts. Preferably the miniature relay switches transmit up to about 50 W of DC or AC line power, and carry up to about 10 A of load current, with an overall volume of less than about 100 mm3. In addition to switching large power, the device preferably requires less than 3 V to actuate, and has a latching feature that retains the switch state after actuation without the need for external applied voltage or current.