Textured Electrode Layout for Sensitive Electric Field Sensing
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Solution Overview
Problem
Sensitivity of electrodes used in quasi-static electric field measurement systems is low, particularly in systems with solid electrodes, making it difficult to detect objects at a distance without significant interference.
Innovation Solution
The electrode arrangement involves optimizing the design by maximizing the distance between the receiving and transmitting electrodes, using active shielding, and texturing the transmitting electrode to reduce capacitance, while maintaining the effective size of the electrodes, thereby enhancing sensitivity and reducing capacitive coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the distance between receiving and transmitting electrodes is increased, then sensitivity to objects is improved, but capacitive coupling between electrodes is reduced
Solution Approach 1:
The patent introduces a third dimension by placing the transmitting electrode on a substrate beneath the receiving electrode, creating a vertical stacking arrangement. This spatial reconfiguration reduces parasitic capacitive coupling while preserving the electric field interaction path, thereby improving sensitivity without sacrificing reliable signal detection
Solution Approach 2:
The substrate acts as an intermediary element between the transmitting and receiving electrodes. It provides electrical isolation to reduce unwanted capacitive coupling while allowing the electric field to penetrate through for object detection, thus mediating between the conflicting requirements of sensitivity and signal reliability
2Area of stationary object
If the size of electrodes is increased to improve detection range, then capacitance increases, but sensitivity decreases due to increased capacitive coupling
Solution Approach 1:
By transitioning from a planar side-by-side electrode arrangement to a vertical stacked configuration, the patent allows larger electrode areas to be implemented without proportionally increasing parasitic coupling. The vertical separation in the third dimension decouples the electrodes while maintaining large surface areas for enhanced detection range
Solution Approach 2:
The substrate provides localized electrical isolation between the transmitting and receiving electrodes. This local separation reduces parasitic capacitive coupling at critical interfaces while allowing the electrodes to maintain large overall areas for improved detection range, achieving local optimization of the electrode interaction
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 approach significantly improves the sensitivity to objects, such as a user's hand, allowing for more accurate and reliable detection in electric field gesture recognition systems.
Implementation Method 1
The field may be generated by a 30-200 kHz, in particular a 70-140 kHz or a 40-115 kHz, signal and thus is quasi-static in the near field
Implementation Method 2
Such sensor systems comprise electrodes that are arranged on the device wherein if a user touches them or gets into very close proximity a change in capacitance can be measured
Data Source
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AI summary
An electrode arrangement for an electric field sensor device with a transmitting electrode and at least one receiving electrode may have a nonconductive substrate having a first conductive layer and a second conductive layer. A first electrode is arranged within the first conductive layer, wherein the first electrode is a receiving electrode of the electric field sensor device, and a second electrode is arranged within the second conductive layer, wherein the second electrode is a transmitting electrode of the electric field sensor device wherein the second electrode covers a larger area than the first electrode and wherein the second electrode is textured to reduce the capacitance between the first and second electrode.