Addressable Sensor Cell Array for Precise Impedance Sensing

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Solution Overview

Problem

Existing sensor arrays face challenges in accurately measuring the impedance of individual sensors due to high resistance, which hinders precise detection of multiple attributes across various locations and times.

Innovation Solution

A sensor arrangement with a transistor and sensor cells connected in series or parallel, utilizing first and second selection circuitry to sequence subsets of sensor cells, allowing for individual addressing and impedance measurement, with sensing signal circuitry providing an indication of impedance changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If sensors are arranged in an array to detect multiple attributes across multiple locations, then the detection capability and coverage are improved, but the resistance increases making impedance measurement difficult

Engineering Contradiction:
Improvedetection capabilityVSAvoidimpedance measurement accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The sensor array is divided into multiple independently addressable sensor cells, each with its own transistor for selection. This segmentation allows individual impedance measurement of each sensor element, overcoming the high resistance problem in large arrays by measuring sensors one at a time rather than all simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A transistor is introduced as an intermediary switching element between the sensing signal circuitry and each sensor. The transistor acts as a controlled switch that connects only the selected sensor to the measurement circuit, enabling precise impedance measurement of individual sensors within the larger array without interference from other sensors.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If individual sensor impedance measurement is implemented in a large sensor array, then measurement precision is improved, but device complexity increases due to additional selection circuitry

Engineering Contradiction:
Improveimpedance measurement precisionVSAvoidselection circuitry complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple sensors are connected in series within each sensor cell, and the selection circuitry merges the control signals to address sensors systematically. The first selection circuitry controls row selection while the second selection circuitry controls column selection, merging these selections to uniquely address individual sensors in the array with minimal circuitry.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensor array is organized in a two-dimensional grid structure with rows and columns. The first selection circuitry selects rows and the second selection circuitry selects columns, adding a spatial dimension to the addressing scheme. This dimensional organization allows individual sensor access with only two selection circuits instead of requiring separate circuits for each sensor.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If sensors are connected in parallel to reduce resistance, then impedance measurement becomes easier, but individual sensor addressing becomes difficult

Engineering Contradiction:
Improveimpedance measurement easeVSAvoidindividual sensor addressing
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The circuit configuration is made dynamic through the use of transistors as switches. Sensors are connected in series but the transistor switches dynamically change the circuit topology by connecting only the selected sensor to the measurement circuit. This dynamic switching allows individual sensor addressing while maintaining series connection benefits for impedance measurement.

Inventive Principle:
Principle #15Dynamics

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

Enables accurate and efficient measurement of impedance changes in sensors, allowing for precise detection of attributes such as user inputs and environmental parameters, with reduced resistance ensuring reliable data collection.

Implementation Method 1

a sensor which produces a measurable change in electrical properties in response to the attributes

Methodology Applied
Scientific EffectImpedance change: Electrical Resistance

Data Source

PatentEP3054597B1An apparatus and methods for sensing
Publication Date: 2020.04.15 NOKIA TECHNOLOGIES OY
  • EP3054597B1 patent drawingFigure 1
  • EP3054597B1 patent drawingFigure 2
  • EP3054597B1 patent drawingFigure 3

AI summary

An apparatus and method wherein the apparatus comprises; a sensor arrangement comprising a plurality of sensor cells wherein a sensor cell comprises a transistor and a sensor coupled to the transistor; first selection circuitry configured to sequence a subset of sensor cells to which a gate input signal is provided, wherein the gate input signal is provided to the gate of the transistors within the sensor cells; second selection circuitry configured to sequence a subset of sensor cells from which an output signal is received; sensing signal circuitry configured to provide a sensing signal, wherein the sensors are provided between the sensing signal circuitry and the second selection circuitry such that the output signal provides an indication of the impedance of the sensors.