Acceleration Sensor Torsion Beam Thickness Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing acceleration sensors for reflective elastic wave exploration in underground resources exploration face challenges in achieving high sensitivity while maintaining a low manufacturing cost, as reducing the spring constant requires expensive equipment and increased chip size, making it difficult to provide a highly sensitive sensor at a low price.
Innovation Solution
The acceleration sensor design includes a membrane with a stacking structure and torsion springs formed from a conductive layer, where the springs have a width smaller than their thickness and length, allowing for a decrease in spring constant without narrowing the beam width or lengthening it, thereby achieving high sensitivity and downsizing the chip without increasing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the spring constant of the beam is reduced by narrowing the width or lengthening the beam, then the sensitivity for vertical acceleration is improved, but the manufacturing cost increases or the chip size increases
Solution Approach 1:
The patent changes the parameter of beam thickness (making it thinner than the membrane thickness) to reduce the spring constant. This allows sensitivity improvement without requiring expensive narrow-beam equipment or increasing chip size, as the thickness parameter can be controlled through standard microfabrication processes.
Solution Approach 2:
Instead of reducing beam width (x-axis) or increasing beam length (y-axis), the patent reduces beam thickness (z-axis). This dimensional shift allows spring constant reduction through a parameter that does not directly impact chip footprint or require specialized manufacturing equipment.
2Measurement precision
If the spring constant of the beam is reduced by narrowing the width of the beam, then the sensitivity for vertical acceleration is improved, but the manufacturing apparatus cost increases
Solution Approach 1:
The patent changes the parameter of beam thickness (making it thinner than the membrane thickness) to reduce the spring constant. This allows sensitivity improvement without requiring expensive narrow-beam equipment or increasing chip size, as the thickness parameter can be controlled through standard microfabrication processes.
3Measurement precision
If the beam length is increased to decrease the spring constant, then the sensitivity is improved, but the chip size increases
Solution Approach 1:
The patent changes the parameter of beam thickness (making it thinner than the membrane thickness) to reduce the spring constant. This allows sensitivity improvement without requiring expensive narrow-beam equipment or increasing chip size, as the thickness parameter can be controlled through standard microfabrication processes.
4Ease of manufacture
If the beam thickness is equalized to the membrane thickness, then the manufacturing is simplified, but the spring constant cannot be sufficiently reduced
Solution Approach 1:
The patent applies different thickness values to different components: the beam thickness is made smaller than the membrane thickness. This local differentiation allows the beam to have sufficiently small spring constant while the membrane maintains its required structural properties.
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
This design enhances the sensitivity and performance of the acceleration sensor while reducing manufacturing costs, allowing for the production of highly sensitive sensors at a lower price by microfabricating the sensor with a short beam length and maintaining accuracy through even thickness formation of the torsion springs.
Implementation Method 1
a capacitance detecting sensor including a membrane (1) having a stacking structure and a plurality of beams (2T1, 2T2) capable of twisting so that the membrane (1) is movable in a detecting direction
Data Source
AI summary
In an acceleration sensor detecting a vibration acceleration by using torsion of a beam joining a fixed portion and a membrane, a spring constant of the beam is decreased while an increase in a chip size due to extension of the beam is prevented, so that an acceleration sensor that is highly sensitive and small in a size is provided with a low price. A sensor of a capacitance detecting type includes a membrane having a stacking structure formed of two or more layers and a plurality of beams capable of twisting so that the membrane is movable in a detecting direction, a first beam of the plurality of beams is formed of the same layer as either an upper or a lower layer of the membrane, and a second beam thereof is formed of the same layer as either an upper or a lower layer of the movable portion.