In-Plane Flexible Pressure Sensor With Compressible Substrate Sensitivity Gain
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pressure sensors either lack flexibility or sensitivity, with in-plane configurations being less sensitive and out-of-plane configurations being less flexible, limiting their practical applications.
Innovation Solution
A flexible pressure sensor with an in-plane configuration using a piezoresistive material layer on a non-electrically conductive substrate, enhancing sensitivity by up to two orders of magnitude through the choice of a compressible substrate like polyurethane foam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If out-of-plane configuration is used with metal interconnects on top and bottom, then electrical measurement is simplified, but flexibility and stretching capacity are notably reduced
Solution Approach 1:
The patent removes the bottom metal interconnect layer from the out-of-plane configuration, extracting only the necessary top interconnect for measurement. This eliminates the harmful effect of rigid bottom contacts while preserving the simplified electrical measurement capability through the remaining top interconnect structure.
Solution Approach 2:
The patent replaces rigid metal interconnects with flexible conducting polymer films that can stretch and bend with the substrate. This allows the electrical measurement function to be maintained while adapting to the flexible nature of the pressure sensor, resolving the contradiction between measurement simplicity and flexibility.
2Adaptability or versatility
If in-plane configuration is used without metal interconnects on top or below, then flexibility is notably improved, but pressure sensitivity is reduced
Solution Approach 1:
The patent uses composite materials consisting of piezoresistive nanocomposites embedded in flexible polymer matrices. This combination provides both the flexibility needed for wearable applications and the pressure sensitivity required for accurate measurement, resolving the trade-off between flexibility and sensitivity in in-plane configurations.
Solution Approach 2:
The patent optimizes parameters such as the concentration of conducting nanoparticles, the composition of the polymer matrix, and the thickness of the sensing layer to simultaneously achieve high flexibility and high pressure sensitivity. By carefully tuning these parameters, the in-plane configuration overcomes its traditional sensitivity limitation.
3Adaptability or versatility
If conducting nanoparticles are embedded in flexible polymer film, then flexibility is achieved, but pressure sensitivity is limited compared to rigid substrates
Solution Approach 1:
The patent employs advanced nanocomposite materials with optimized nanoparticle distributions and polymer matrix compositions that enhance the piezoresistive effect while maintaining flexibility. This composite approach allows the sensor to achieve pressure sensitivity comparable to rigid substrates while retaining the essential flexibility for wearable applications.
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 sensor achieves high flexibility and sensitivity, with sensitivity increased by a factor of 100 to 125, overcoming limitations of existing sensors by eliminating the need for additional metallic pieces and improving durability.
Implementation Method 1
at least one piezoresistive material layer... For this energy transformation active sensing materials are indispensable... piezoresistivity (perhaps the most common)
Implementation Method 2
a substrate made of a flexible, compressible and non-electrically conductive polymer... enhancing sensitivity by up to two orders of magnitude through the choice of a compressible substrate
Data Source
Figure 1(a)~2
Figure 3(a)~3(d)
Figure 4~5
AI summary
The present invention belongs to the field of sensors, and more precisely discloses a flexible pressure sensor measured via an in-plane (e.g. coplanar) configuration comprising at least one piezoresistive material layer and at least a substrate made of a flexible, compressible and non-electrically conductive polymer. The pressure sensor of the invention presents both high flexibility as well as improved pressure sensitivity, compared to other pressure sensors of the state of the art.