CMOS Electrochemical Imaging Chip With Op-Amp-Less Potentiostat

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Solution Overview

Problem

Existing implantable micro-scale chips for electrochemical measurement face challenges due to excessive power consumption, which limits their utility and efficiency in measuring target analytes, and lack integration of impedance spectroscopy circuits.

Innovation Solution

An integrated circuit with an ultra-low power op-amp-less delta-sigma-ADC-based potentiostat and computationally-efficient impedance spectroscopy circuit, utilizing a CMOS chip with an inductive power transfer system and zero-hysteresis comparator to minimize power consumption and maintain high-speed and low noise performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional potentiostat circuits are used in implantable micro-scale chips, then electrochemical measurement function is achieved, but power consumption becomes excessive

Engineering Contradiction:
Improvepower consumptionVSAvoidmeasurement reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent extracts and removes the operational amplifier from the conventional potentiostat circuit, creating an op-amp-less design. This extraction eliminates the primary source of high power consumption while maintaining the essential electrochemical measurement function through alternative circuit architecture using transistors and capacitors for signal amplification and integration.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the operating parameters of the circuit by using ultra-low power design techniques, including optimized transistor biasing and switching operations. The circuit operates in discrete-time domains with sampled signals, allowing measurements to be performed with minimal power dissipation while maintaining measurement accuracy and reliability.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If power consumption is reduced to ultra-low levels, then battery life and utility are improved, but measurement speed and noise performance may deteriorate

Engineering Contradiction:
Improvepower consumptionVSAvoidresponse speed
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The patent employs periodic sampling of electrochemical signals at optimized intervals, allowing the circuit to remain in low-power standby mode between measurements while capturing sufficient data points to maintain measurement speed. The periodic activation of measurement circuits enables ultra-low average power consumption without sacrificing essential response time for detecting analyte changes.

Inventive Principle:
Principle #19Periodic action

3Adaptability or versatility

If conventional impedance spectroscopy circuits are integrated, then comprehensive analyte measurement is achieved, but device complexity and power consumption increase

Engineering Contradiction:
Improvemeasurement capabilityVSAvoidcircuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent designs a universal potentiostat circuit architecture that can perform multiple electrochemical measurement functions including amperometry, voltammetry, and impedance spectroscopy using the same basic op-amp-less circuit structure. This multi-functionality is achieved through software-controlled measurement protocols and signal processing rather than requiring separate dedicated hardware circuits for each measurement type, thereby reducing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution achieves significant reduction in power consumption, with approximately 50 Nanowatts of power usage, enabling faster response and lower power consumption compared to other ultra-low power designs, while maintaining high-speed and low noise performance, and allowing for in situ high-spatial resolution measurement of electrochemically detectable analytes.

Implementation Method 1

utilizing a CMOS chip with an inductive power transfer system

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3307163B1Systems for in situ electrochemical imaging
Publication Date: 2023.03.08 THE GOVERNING COUNCIL OF THE UNIV OF TORONTO
  • EP3307163B1 patent drawingFigure 1
  • EP3307163B1 patent drawingFigure 2
  • EP3307163B1 patent drawingFigure 3

AI summary

Systems, methods and apparatuses described herein generally provide a millimetre size package-free complementary metal–oxide–semiconductor ("CMOS") chip (referred to as a "die") for the in situ (on-site) measurement or imaging of electrochemically detectable analytes.