Microfluidic Electrode Driving Circuit With Feedback DC Offset Control

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Solution Overview

Problem

Microfluidic devices face issues with harmonic distortion and DC offset control, leading to inefficiency, heat generation, and potential electro-corrosion when driving signals are applied, compromising the sorting and routing capability of particles.

Innovation Solution

An electronic driving circuit with synchronized switching-mode amplifier stages and a closed-loop feedback system is used to generate driving signals with controlled frequency, amplitude, and phase-shift, minimizing harmonic distortion and maintaining a unique DC offset, thereby reducing heat dissipation and preventing electro-corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional amplifier circuits are used to generate driving signals for microfluidic electrodes, then the device can operate, but harmonic distortion increases and DC offset control deteriorates

Engineering Contradiction:
ImproveDC offset controlVSAvoidharmonic distortion
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent implements a closed-loop feedback system where the actual driving signals applied to electrodes are monitored and fed back to a controller. The controller adjusts the signals in real-time to maintain precise DC offset control and minimize harmonic distortion, resolving the contradiction between reliability and manufacturing precision

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts signal parameters (amplitude, frequency, phase) through synchronized switching-mode amplifier stages. By changing operational parameters adaptively rather than using fixed conventional amplification, the system achieves both low harmonic distortion and precise DC offset control

Inventive Principle:
Principle #35Parameter changes

2Productivity

If driving signals with uncontrolled DC offset are applied to electrodes, then the system operates, but electro-corrosion and heat generation increase

Engineering Contradiction:
Improvesorting capabilityVSAvoidelectro-corrosion
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The feedback mechanism continuously monitors the DC offset component of driving signals and adjusts amplifier output to maintain zero or controlled DC offset. This prevents electro-corrosion of electrodes while preserving the sorting capability, resolving the contradiction between productivity and harmful factors

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system proactively prevents electro-corrosion by eliminating DC offset components before they can cause damage. The synchronized switching-mode amplifiers are designed to inherently block DC components, and the feedback system ensures any residual DC offset is corrected preemptively

Inventive Principle:
Principle #9Preliminary anti-action

3Power

If conventional amplification is used, then driving signals can be generated, but heat dissipation increases and efficiency decreases

Engineering Contradiction:
Improvesignal amplitudeVSAvoidheat dissipation
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent replaces conventional linear amplification (analog mechanical-like system) with synchronized switching-mode amplification (digital-like system). The switching amplifiers operate in saturation regions with binary switching, dramatically reducing resistive losses and heat dissipation while maintaining required signal power levels

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system uses periodic switching signals at the operating frequency to drive electrodes. By using pulsed periodic action rather than continuous analog amplification, the system achieves efficient power transfer with minimal heat generation, resolving the contradiction between power output and energy loss

Inventive Principle:
Principle #19Periodic action

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 high efficiency, reliability, and thermal stability with reduced harmonic distortion and DC offset, ensuring precise control over driving signals for microfluidic devices, enhancing particle sorting and routing capabilities.

Implementation Method 1

the microfluidic device is a device for selection and sorting of cells immersed in a fluid, by dielectrophoresis... based on dielectrophoresis (DEP), i.e. the physical phenomenon whereby neutral particles, when subject to nonuniform, time stationary (DC) or time varying (AC) electric fields, experience a net force

Methodology Applied
Scientific EffectDielectrophoresis: Dielectric Permittivity

Implementation Method 2

leading to inefficiency, heat generation, and potential electro-corrosion when driving signals are applied... minimizing harmonic distortion and maintaining a unique DC offset, thereby reducing heat dissipation and preventing electro-corrosion

Methodology Applied
Scientific EffectJoule Heating: Joule Heating

Data Source

PatentEP3529895B1Electronic driving circuit for driving electrodes of a microfluidic device for manipulation of particles, and corresponding analysis apparatus
Publication Date: 2021.04.21 MENARINI SILICON BIOSYSTEMS SPA
  • EP3529895B1 patent drawingFigure 1~2
  • EP3529895B1 patent drawingFigure 3
  • EP3529895B1 patent drawingFigure 4

AI summary

An electronic driving circuit (20) for a microfluidic device (1), having a number of synchronized driving stages (22) to generate a respective driving signal (Vi,V2,V3) for each electrode or group of electrodes (4,6) of the microfluidic device, the driving signals having a desired amplitude, frequency and phase-shift. Each driving stage has a switching-mode amplifier stage (22) to receive a clock signal (CK) and a target signal (Vt) and to generate, at an output (Out) thereof, an output signal (Vout) defining a respective driving signal. The amplifier stage has: a switching module (23), coupled to a first internal node (N1) and controlled by the clock signal for selectively bringing the first internal node (N1) to a control signal (Vc); a filter module (25,26), coupled between the first internal node and the output, to provide the output signal; and a feedback module (29).