Embedded-Electrode Piezoelectric Sensor for Lateral Force Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piezoelectric sensors struggle to effectively detect lateral forces, shear forces, and torque due to their sensitivity being predominantly focused on normal components, leading to inadequate detection of tangential components and other lateral stresses.
Innovation Solution
A piezoelectric sensor design with embedded electrodes at an angle, preferably 90 degrees, within the piezoelectric material, utilizing anisotropic electromechanical coupling to enhance sensitivity to lateral stresses, allowing detection of tangential forces, shear forces, and torque by embedding electrodes in the material to maximize sensitivity to lateral stress components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensor material is embodied as a sensor film with conventional electrode arrangement, then the sensor can detect normal forces effectively, but the sensitivity to lateral forces, shear forces, and torque is limited
Solution Approach 1:
The patent extends the electrode arrangement from a two-dimensional surface configuration to a three-dimensional embedded structure. Electrodes are positioned at right angles within the piezoelectric material bulk, enabling detection of lateral forces, shear forces, and torque in addition to normal forces. This dimensional transition allows the sensor to capture stress components that were previously undetectable with surface-only electrode arrangements.
Solution Approach 2:
The sensor design achieves multi-functionality by enabling detection of multiple force types (normal forces, lateral forces, shear forces, and torque) using a single integrated sensor structure. The anisotropic piezoelectric material combined with the three-dimensional electrode arrangement allows the same sensor to respond to different stress components, eliminating the need for multiple specialized sensors.
2Measurement precision
If the sensor uses isotropic piezoelectric material with conventional electrode placement, then the structure is simple, but it cannot distinguish between different directions of applied forces
Solution Approach 1:
The patent introduces asymmetry in the electrode arrangement by positioning electrodes at right angles within the piezoelectric material rather than symmetrically on opposite surfaces. This asymmetric configuration, combined with the anisotropic material properties, enables the sensor to differentiate between force directions. The electrodes are embedded at specific orientations (e.g., 0°, 45°, 90°) to capture different stress components.
Solution Approach 2:
The patent utilizes changes in material parameters by employing piezoelectric materials with anisotropic electromechanical coupling. The material's directional sensitivity (different piezoelectric coefficients along different crystal axes) is exploited to enhance force direction discrimination. By selecting materials with specific anisotropic properties and matching them with corresponding electrode orientations, the sensor achieves improved directional measurement capability.
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 design significantly enhances sensitivity to lateral forces, shear forces, and torque, providing accurate detection and quantification of these stress components, and can also detect temperature changes and acoustic waves, making it suitable for self-sustained sensor networks.
Implementation Method 1
Active sensors for the detection of forces are usually based on the piezoelectric effect. When a force is applied to a surface of the sensor, the mechanical stress is partly transformed into electrical energy which may be a qualitative and quantitative measure for the applied force.
Implementation Method 2
the piezoelectric material has an anisotropic electromechanical coupling and the at least one first and second electrodes are at least in part embedded in the piezoelectric material
Data Source
AI summary
A piezoelectric sensor, comprising at least one first electrode, at least one second electrode, and a piezoelectric material, wherein the piezoelectric material has an anisotropic electromechanical coupling and the at least one first and second electrodes are at least in part embedded in the piezoelectric material, the piezoelectric material having a first surface wherein the electrodes extend vertically within the piezoelectric material from the first surface.