MEMS Pressure Sensor Protective Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing MEMS pressure detectors with a cavity structure are prone to damage and inaccurate pressure detection due to external contact, as they lack sufficient protection for the pressure sensor.
Innovation Solution
A MEMS device design featuring a variable capacitor with a protective structure surrounding the pressure-sensitive section, formed from the same materials as the capacitor and sensor, which is positioned higher than the sensor to prevent external contact and maintain accurate pressure detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a cavity is provided within the pressure sensor, then the pressure sensor can detect pressure accurately, but the strength of the pressure sensor becomes weak and vulnerable to external contact
Solution Approach 1:
The pressure sensor is nested within the protective structure, which has a cavity that accommodates the pressure sensor. This nested configuration allows the pressure sensor to maintain its cavity for accurate pressure detection while being protected by the outer protective structure with wall surfaces that prevent direct external contact.
Solution Approach 2:
The protective structure acts as an intermediary between the external environment and the pressure sensor. It has a cavity that accommodates the pressure sensor and wall surfaces that mediate external forces, preventing direct contact with the pressure sensor while allowing pressure detection to function.
2Reliability
If a protective structure is added around the pressure-sensitive section, then external contact is prevented, but the device complexity increases
Solution Approach 1:
The protective structure serves multiple functions: it protects the pressure sensor from external contact, provides a cavity to accommodate the pressure sensor, and maintains the structural integrity of the device. This multi-functionality reduces the need for additional separate protective components.
Solution Approach 2:
The protective structure is integrated with the pressure sensor assembly, combining the protective function with the housing or packaging structure. This merging approach avoids adding separate protective components and reduces overall device complexity.
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 protective structure effectively inhibits external contact, preventing damage and ensuring accurate pressure detection by maintaining the integrity of the pressure-sensitive section while sharing materials with the variable capacitor and sensor, thus simplifying manufacturing and enhancing operational reliability.
Implementation Method 1
the capacitance of the variable capacitor varies according to the pressure and thus the pressure can be detected
Implementation Method 2
the pressure sensor is connected to an upper electrode of the variable capacitor, and the upper electrode of the variable capacitor is displaced according to the displacement of the pressure sensor
Data Source
AI summary
According to one embodiment, a MEMS device includes a variable capacitor including a lower electrode fixed to a substrate and a movable upper electrode provided above the lower electrode, a pressure-sensitive section covering the variable capacitor and connected to the upper electrode, configured to displace according to a pressure applied, and a protective structure provided on an outer side of the pressure-sensitive section.