Microfluidic Temperature Measurement via Fluorescence Diffusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current microfluidic analysis devices face challenges in accurately measuring fluid temperature without calibration, especially in optofluidic systems, as traditional methods like thermocouples can interfere with the device's functionality and require additional components.
Innovation Solution
A method and device that utilize a fluid-specific diffusion constant to determine temperature by analyzing the diffusion of a fluorescent agent, allowing for calibration-free, in-situ temperature measurement using a camera and illumination system, which reads diffusion signals to calculate the temperature through partial differential equations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional temperature measurement methods like thermocouples are used in microfluidic devices, then temperature can be measured, but the device functionality is interfered with and additional components are required
Solution Approach 1:
The patent replaces mechanical/physical temperature sensors (thermocouples) with an optical measurement system that uses fluorescence intensity ratios to determine temperature. The system excites temperature-sensitive fluorescent dyes and measures the ratio of fluorescence intensities at different wavelengths, eliminating the need for physical contact sensors that interfere with microfluidic operations.
Solution Approach 2:
The patent introduces temperature-sensitive fluorescent dyes as intermediaries between the temperature field and the measurement system. These dyes absorb optical excitation and convert it to fluorescence emission with intensity ratios that depend on temperature, serving as a non-invasive mediator that translates thermal information into optical signals without interfering with device functionality.
2Measurement precision
If traditional temperature measurement methods are used, then temperature can be measured, but calibration is required which adds manual steps and potential errors
Solution Approach 1:
The patent implements a self-calibrating system that uses the intrinsic temperature dependence of fluorescence intensity ratios. The system automatically determines temperature by measuring the ratio of fluorescence intensities at different emission wavelengths, which inherently contains temperature information without requiring external calibration standards or manual intervention. The measurement process itself provides the calibration reference through the known spectral properties of the fluorescent dyes.
3Measurement precision
If additional temperature sensors are added to microfluidic devices, then temperature measurement is enabled, but the miniaturization and automation benefits are reduced
Solution Approach 1:
The patent makes the optical system serve multiple functions: it simultaneously performs fluorescence-based temperature measurement and maintains compatibility with the microfluidic analysis functions. The same optical excitation and detection infrastructure used for other optical measurements in the microfluidic device is leveraged for temperature sensing, eliminating the need for separate dedicated temperature sensor components and preserving miniaturization benefits.
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 precise, calibration-free temperature measurement and control within microfluidic systems, reducing the need for additional sensors and manual steps, and allowing dynamic adjustment of temperature settings, thus improving the accuracy and efficiency of temperature-sensitive biochemical assays.
Implementation Method 1
The diffusion characteristic is detected using at least one aid introduced into the fluid, in particular a fluorescent agent, and using at least one camera image
Implementation Method 2
at least one diffusion signal is read in, which represents a diffusion characteristic of a diffusion of the fluid
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The approach presented here relates to a method for measuring the temperature (110) of a fluid (120) for use with a microfluidic analysis device (100). The method comprises a reading step and a determination step. In the reading step, at least one diffusion signal (125) is read in, representing a diffusion characteristic of the diffusion of the fluid (120). In the determination step, the temperature (110) is determined using the at least one diffusion signal (125).