MEMS Microswitch Dual Actuator Shared Gate Driver
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional MEMS switches are prone to self-actuation at high voltages, leading to catastrophic failure, as the electrostatic force can cause the beam to self-actuate without a gating signal, resulting in unintended contact and system failure.
Innovation Solution
A MEMS switch design featuring dual actuating elements sharing a common gate driver, which distributes the actuation voltage equally between the elements, preventing self-actuation by maintaining differential voltages within safe limits and incorporating a shared gate driver to manage the electrostatic force effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single actuator is used in conventional MEMS switches, then the device structure is simple, but the voltage standoff capability is limited and self-actuation occurs at high voltages
Solution Approach 1:
The movable actuator is divided into two separate actuators (first actuator and second actuator) that are electrically coupled together. This segmentation allows the voltage standoff capability to be doubled while maintaining a compact structure, as each actuator handles half of the total voltage stress independently
Solution Approach 2:
The two actuators are electrically coupled and mechanically integrated to share a common gate driver and support structure. This merging approach allows the system to achieve higher voltage standoff capability without proportionally increasing the overall device footprint or complexity
2Reliability
If electrostatic force is applied to a single beam, then the actuation mechanism is simple, but self-actuation occurs without gating signal at high voltages
Solution Approach 1:
The electrostatic actuation force is divided and applied to two separate actuators instead of one beam. This segmentation prevents self-actuation by distributing the electrostatic stress, so that each actuator experiences reduced force that cannot cause unintended contact without proper gating signal
Solution Approach 2:
The electrical coupling between the two actuators acts as an intermediary mechanism that distributes the actuation voltage equally across both actuators. This intermediary connection ensures that the differential voltage remains within safe limits and prevents self-actuation while maintaining coordinated operation
3Reliability
If the switch footprint is increased to handle higher voltages, then the voltage standoff capability improves, but the device area increases
Solution Approach 1:
The two actuators share common structural elements including the gate driver, support beams, and anchor points. This merging of common components allows the voltage standoff capability to be doubled while minimizing the increase in overall device area, as the shared structures eliminate the need for completely separate actuator systems
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 design significantly increases the voltage standoff capability of the MEMS switch, preventing self-actuation and ensuring reliable operation at higher voltages without increasing the switch footprint, thereby enhancing the reliability and safety of the switching mechanism.
Implementation Method 1
A MEMS device in the form of a microswitch has a movable actuator, sometimes referred to as a movable electrode, that is moved toward a stationary electrical contact by the influence of a gate driver (also referred to as a gate or substrate electrode) positioned on a substrate below the movable actuator
Implementation Method 2
If a large enough differential voltage exists between the free end of the beam and the stationary electrical contact, a resulting electrostatic force can cause the beam to self-actuate without any gating signal being provided by a gate driver
Data Source
Figure 1~2
Figure 3~5
Figure 6
AI summary
In accordance with one aspect of the present invention, a MEMS switch 10,30,40 is provided. The MEMS switch 10,30,40 includes a substrate 12, a first 21,41 and a second 22,42 actuating element electrically coupled together, an anchor 18 mechanically coupled to the substrate 12 and supporting at least one of the first 21,41 and second 22,42 actuating elements, and a gate driver 6 configured to actuate the first 21,41 and second 22,42 actuating elements.