Microfluidic Photon Detection Timing for Compact Analysis
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Solution Overview
Problem
Conventional in-liquid microparticle analysis systems are hindered by the complexity and size of optical systems required to separate excitation light and fluorescence for detection, which limits their compactness and efficiency.
Innovation Solution
An integrated circuit chip with a microfluidic channel and a photon detection unit, where the photon detection operation is synchronized with the excitation light source, allowing detection of fluorescent photons after the excitation light is switched off, eliminating the need for optical filters and enabling a compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical filters are used to separate excitation light and fluorescence for detection, then detection accuracy is improved, but device complexity and size increase
Solution Approach 1:
The patent extracts and removes the optical filter component from the system by using temporal separation instead of spectral separation. The excitation light source is pulsed, and fluorescence detection is performed during the pulse interval when excitation light is off, eliminating the need for optical filters to separate excitation light and fluorescence wavelengths.
Solution Approach 2:
The patent replaces the mechanical/optical filtering system with a temporal control system. Instead of using physical optical filters to separate wavelengths, the system uses synchronized timing control to detect fluorescence only during periods when excitation light is not present, substituting a control-based approach for an optical-component-based approach.
2Measurement precision
If optical filters are used to separate excitation light and fluorescence, then fluorescence detection is enabled, but the optical system size increases
Solution Approach 1:
The patent removes bulky optical filter components from the system by implementing temporal separation of excitation and detection. The excitation light source operates in pulsed mode, and fluorescence detection is synchronized to occur during the pulse interval, eliminating the need for physical wavelength separation components that occupy space.
Solution Approach 2:
The patent employs periodic pulsing of the excitation light source with corresponding periodic detection windows. The excitation light is turned on and off in regular intervals, and fluorescence detection is performed during the off-periods, creating a rhythmic pattern of excitation and detection that eliminates the need for continuous optical filtering.
3Duration of action of stationary object
If continuous excitation light is used, then fluorescence generation is maintained, but detection of weak fluorescent molecules becomes difficult due to excitation light interference
Solution Approach 1:
The patent converts continuous excitation into periodic pulsed excitation. The excitation light source is activated in repeated short pulses, and fluorescence detection is synchronized to occur during the intervals between pulses. This periodic pattern maintains overall fluorescence generation while eliminating excitation light interference during detection periods.
Solution Approach 2:
The patent applies preliminary anti-action by turning off the excitation light before fluorescence detection begins. The timing control system preemptively stops excitation light emission prior to the detection window, preventing excitation light from interfering with the detection of weak fluorescent signals, thereby improving signal-to-noise ratio.
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 approach reduces the size and complexity of the optical system while maintaining effective detection of fluorescent photons, even for weak fluorescent molecules, by repeating photon detection operations during the time a target passes through the microfluidic channel.
Implementation Method 1
detecting light scattering and fluorescence generated by analysis-target microparticles through irradiation with the excitation light
Implementation Method 2
a photon detection unit including a photodiode is incorporated
Data Source
AI summary
A size reduction in an optical system that detects a fluorescent photon is achieved. A photon detection operation of a photon detection unit (21) is controlled on the basis of timing of an irradiation operation of an excitation light source (50), and after excitation light emitted to a microfluidic channel (10) is switched off, a fluorescent photon generated by a target flowing in the microfluidic channel (10) is detected.