Piezoresistive Sensor With Convex Electrodes and Porous Foam
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Solution Overview
Problem
Conventional resistive pressure sensors have insufficient sensitivity due to the limited elasticity of their piezoresistive material layers, making it difficult to detect small pressure changes effectively.
Innovation Solution
A pressure sensing device with a sheet-like piezoresistive material layer and electrode structures featuring uneven surfaces, including convex points, which increases contact area with the piezoresistive material layer upon pressure application, enhancing sensitivity. The piezoresistive material layer is made of porous foam with absorbed graphene particles, and the electrode structures are designed with configuration layers and electrode layers to form non-planar surfaces for improved contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional piezoresistive material layer with limited elasticity is used, then the sensor structure is simple, but the sensitivity is insufficient and small pressure changes cannot be detected effectively
Solution Approach 1:
The electrode structures are designed with convex protrusions (curved surfaces) instead of flat surfaces. These convex structures increase the contact area with the piezoresistive material layer when pressure is applied, thereby improving pressure sensing sensitivity while maintaining a relatively simple overall device structure.
Solution Approach 2:
The piezoresistive material layer is designed as a porous foam body, which provides enhanced elasticity and deformability. This porous structure allows the material to be easily compressed and deformed under small pressure changes, significantly improving the sensor's sensitivity without requiring complex electrode configurations.
2Measurement precision
If the piezoresistive material layer is made thicker to improve pressure detection, then sensitivity improves, but the sensor thickness increases and portability decreases
Solution Approach 1:
The porous foam body structure provides high elasticity and compressibility within a thin profile. This allows the piezoresistive material layer to achieve effective pressure detection in a compact, thin form factor, improving both sensitivity and portability simultaneously.
Solution Approach 2:
The convex protrusions on the electrode structures concentrate pressure contact points, enhancing the pressure sensing effect in a thin configuration. This curved surface design allows effective pressure detection without requiring increased sensor thickness.
3Measurement precision
If a flat electrode surface is used, then manufacturing is simple, but contact area with piezoresistive material is insufficient reducing sensitivity
Solution Approach 1:
The convex protrusions are formed using conventional molding or 3D printing techniques, which are relatively simple manufacturing processes. These curved structures increase contact area with the piezoresistive material while maintaining ease of manufacture through standard fabrication methods.
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 significantly improves pressure sensing accuracy and sensitivity by increasing the contact area between the piezoresistive material layer and electrode structures, allowing for more precise detection of pressure changes, and reduces the thickness of the sensor while maintaining effective pressure detection capabilities.
Implementation Method 1
the piezoresistive material layer includes porous foam body and graphene particles absorbed on the porous foam body
Implementation Method 2
When a pressure is applied to the elastic thin film, a contact level between the conductive materials or a contact area between the thin film and the electrode layers increases, so as to change a resistance of the piezoresistive material layer
Data Source
AI summary
The present disclosure provides a pressure sensing device, including a sensor. The sensor includes a sheet-like piezoresistive material layer, and a first electrode structure and the second electrode structure arranged at opposite sides of the piezoresistive material layer respectively. At least one of the first electrode structure and the second electrode structure is provided with one or more protrusions at a surface facing the piezoresistive material layer, and the surface facing the piezoresistive material layer with the one or more protrusions forms an uneven surface.