Integrated Circuit Impedance Sensing for Biological Molecules
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Solution Overview
Problem
Current integrated circuits for sensing biological molecules face challenges in achieving high accuracy, sensitivity, and speed while minimizing power consumption, particularly in measuring the impedance of biological samples like polynucleotides, due to limitations in measurement circuitry integration and ancillary capacitance interference.
Innovation Solution
The integrated circuit design includes a cell array with measurement cells equipped with sensing circuits, row and cell write logic, analog multiplexers, column amplifiers, and analog-to-digital converters, along with AC sensing modes to mitigate ancillary capacitance and enhance measurement precision, utilizing a pre-charged capacitor or current mirror circuits for impedance detection and incorporating synchronized AC waveforms for accurate impedance measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If measurement circuitry is integrated with the cell array to achieve fast measurement times and reduced power consumption, then measurement speed and power efficiency are improved, but measurement precision deteriorates due to ancillary capacitance interference
Solution Approach 1:
The patent extracts and separates the ancillary capacitance from the measurement circuit by implementing a dedicated capacitance cancellation circuit that independently measures and subtracts the parasitic capacitance contribution from the total measured impedance, thereby eliminating its interfering effect on measurement precision while maintaining the integrated circuit architecture
Solution Approach 2:
The patent changes the measurement parameters by implementing AC impedance measurement at multiple frequencies and using phase-sensitive detection to distinguish between resistive and capacitive components, allowing the system to compensate for ancillary capacitance effects and achieve high precision measurements despite the integrated architecture
2Use of energy by moving object
If measurement circuitry is integrated with the cell array to reduce power consumption, then energy efficiency is improved, but measurement accuracy deteriorates due to circuit interference
Solution Approach 1:
The patent introduces intermediary compensation circuits that act as mediators between the measurement signal and the ancillary capacitance, using operational amplifiers configured as virtual ground nodes to prevent capacitive coupling interference while maintaining low power consumption through efficient circuit topologies
Solution Approach 2:
The patent implements feedback mechanisms where the measured impedance signal is fed back through a differential amplifier configuration that continuously compensates for drift and interference from the integrated circuit components, maintaining measurement accuracy without requiring additional power-consuming shielding or isolation components
3Productivity
If large arrays of individual cells are used to facilitate high throughput and parallel processing, then productivity is improved, but device complexity increases
Solution Approach 1:
The patent implements universal readout circuits that can simultaneously interface with multiple measurement cells through multiplexing, where a single amplifier and ADC configuration can service entire rows or columns of the cell array, thereby achieving high throughput without proportionally increasing circuit complexity
Solution Approach 2:
The patent segments the large cell array into manageable blocks with shared readout infrastructure, where groups of measurement cells are organized in rows and columns that can be independently addressed and read out through shared amplifiers and multiplexers, reducing the overall circuit complexity while maintaining high parallel processing 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
This design improves the accuracy and sensitivity of biological molecule impedance measurement, reduces power consumption, and increases throughput by integrating multiplexing functions and using AC modes to decouple ancillary capacitance, thereby addressing the limitations of existing technologies.
Implementation Method 1
a sensing circuit configured to measure the impedance of a biological sample under test
Implementation Method 2
applying an AC waveform to CE
Implementation Method 3
sampling the voltage of the AC waveform
Data Source
AI summary
Integrated circuits for sensing biological molecules are disclosed. The integrated circuits can be used to measure the impedance of a biological sample under test. The integrated circuits can be used to sequence polynucleotides using a cell array.