MEMS Optical Shutter with Rotating Shielding Structures

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Solution Overview

Problem

Existing MEMS optical shutters lack the ability to control the optical aperture with a large number of degrees of freedom, limiting their functionality compared to professional cameras which can adjust the aperture variably.

Innovation Solution

A MEMS optical shutter with translating shielding structures, comprising a substrate with dielectric regions and conductive layers, and a manufacturing process that involves forming shielding structures with piezoelectric actuators to control the optical aperture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single bonded layer with etched shutter blades is used, then the device structure is simplified, but the degrees of freedom for aperture adjustment are limited

Engineering Contradiction:
Improvedevice structureVSAvoiddegrees of freedom for aperture adjustment
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The single bonded layer is divided into multiple independent shutter blades, each capable of independent actuation. This segmentation allows each blade to be controlled separately by individual microactuators, thereby increasing the degrees of freedom for aperture adjustment while maintaining the simplicity of the single-layer structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shutter blades are designed to be dynamically movable rather than fixed, enabling synchronous shifting of multiple blades to form a variable polygonal aperture. This dynamic configuration allows the aperture shape and size to be adjusted in real-time, providing versatile control over light transmission

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If multiple-blade irises are implemented, then the aperture control versatility is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveaperture control versatilityVSAvoidmanufacturing process
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Multiple shutter blades are merged into a single bonded layer structure, where all blades are formed in one continuous substrate. This merging approach allows multiple blades to be manufactured simultaneously using a single etching process, reducing manufacturing complexity while maintaining aperture control versatility

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single bonded layer serves multiple functions: it provides the structural substrate for all shutter blades, acts as the etching template for forming blade shapes, and serves as the mounting platform for microactuators. This multi-functionality simplifies the manufacturing process by eliminating the need for separate fabrication steps for each component

Inventive Principle:
Principle #6Universality (Multi-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

The solution allows for precise control of the optical aperture over the entire perimeter of the main aperture, providing a large number of degrees of freedom for adjustment, thus enhancing the functionality of the MEMS optical shutter.

Implementation Method 1

shielding structures with piezoelectric actuators to control the optical aperture

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4187289B1Micro-electro-mechanical optical shutter with rotating shielding structures and related manufacturing process
Publication Date: 2025.01.29 STMICROELECTRONICS SRL
  • EP4187289B1 patent drawingFigure 1
  • EP4187289B1 patent drawingFigure 2
  • EP4187289B1 patent drawingFigure 3

AI summary

A MEMS shutter including: a substrate (2) of semiconductor material traversed by a main aperture (9), and a first semiconductor layer (14) and a second semiconductor layer (16), which form a supporting structure (28, 71) fixed to the substrate; a plurality of deformable structures (29, 59, 69); a plurality of actuators (36; 96); and a plurality of shielding structures (33; 35; 333; 335; 433), each of which is formed by a corresponding portion of at least one between the first semiconductor layer and the second semiconductor layer, the shielding structures being arranged angularly around the underlying main aperture so as to provide shielding of the main aperture, each shielding structure being further coupled to the supporting structure via a corresponding deformable structure. Each actuator may be controlled so as to cause a rotation of a corresponding shielding structure between a respective first position and a respective second position, thus varying shielding of the main aperture. The first and second positions of the shielding structures are such that, in at least one operating condition of the MEMS shutter (1), pairs of adjacent shielding structures at least partially overlap one another.