Capacitance-Based Matter Sensing With Noise-Resistant AC Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sensors have undesirably low sensitivity to detect features of interest, resulting in weak signals that are not useful for detection, and are susceptible to noise from charge buildup and stray charges.
Innovation Solution
The technique measures capacitance or transconductance between a control terminal and a semiconductor channel to indicate the presence of matter, which is less susceptible to noise, using AC voltage signals with specific frequencies to enhance signal strength and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sensors are used to detect features of interest, then the sensor structure is simple, but the sensitivity is low and signals are too weak to be useful
Solution Approach 1:
The patent replaces conventional mechanical or passive sensing mechanisms with an electrical field-based detection system. By applying voltage to the control terminal and measuring resulting current changes through the semiconductor channel, the system converts physical matter detection into electrical signal measurement, achieving high sensitivity without complex mechanical structures
Solution Approach 2:
The invention utilizes changes in electrical parameters (capacitance and transconductance) as indicators of matter presence. By monitoring how voltage application affects current flow through the semiconductor channel, the system detects matter at the sensor surface through parameter changes rather than direct mechanical interaction
2Measurement precision
If conventional sensing methods are used, then the measurement process is simple, but noise from charge buildup and stray charges interferes with detection accuracy
Solution Approach 1:
The patent converts the potentially harmful effect of charge buildup and stray charges into a beneficial detection mechanism. By applying AC voltage and measuring current changes, the system uses these electrical phenomena as the basis for detection, filtering out noise through frequency-based analysis and transforming what would be interference into the detection signal itself
Solution Approach 2:
The invention employs periodic AC voltage signals to drive the sensing process. By using alternating current at specific frequencies and analyzing the resulting periodic current responses, the system distinguishes signal from noise through frequency filtering, eliminating the interference of DC charge buildup and stray charges
3Reliability
If capacitance measurement is used to detect matter, then signal strength is enhanced and noise is reduced, but the measurement process becomes more complex
Solution Approach 1:
The patent makes the existing sensor structure multi-functional by enabling it to measure both capacitance and transconductance through a unified voltage application and current measurement process. This allows a single sensor design to provide multiple detection capabilities without adding separate measurement systems, maintaining simplicity while enhancing reliability
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 provides more accurate detection of matter at a sensor surface by leveraging capacitance or transconductance, reducing noise interference and enhancing signal strength, allowing for precise detection of matter, including biomarkers like GFAP, S100B, UCH-L1, and NFL-1, with resolution on the order of picometers.
Implementation Method 1
determining, using the current, a capacitance of the sensor indicative of the matter at a surface of the sensor
Implementation Method 2
the capacitance may be indicative of a change in dielectric constant at the surface of the sensor
Data Source
AI summary
Described herein are techniques that, in some embodiments, leverage a detected change in capacitance of a sensor to indicate the presence of matter proximate the sensor. In some embodiments, buildup of matter at a sensor surface may contribute to a change in capacitance between a control terminal of the sensor and a channel of the sensor, such as by changing an effective dielectric constant between the control terminal and the semiconductor channel. Advantageously, noise charges may contribute less or not at all to such a change in capacitance, such as by having less or no impact on the effective dielectric constant. As such, in some embodiments, measuring a change in capacitance of a sensor may provide a more accurate indication of buildup of matter at a sensor surface than a detection of charge buildup at the sensor.