Biosensor Chip Integrating Grating and Nanofocusing for Noise Reduction
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Solution Overview
Problem
Current biochemical detection technologies require external optical elements and complex optical paths, leading to large, costly, and time-consuming instruments that are not suitable for portable or rapid medical scenarios, especially in primary medical settings, due to insufficient signal-to-noise ratio and crosstalk noise in fluorescence detection systems.
Innovation Solution
A biosensor with a CMOS image sensor, a light signal filter layer, metal nanometer light focusing units, and a grating array layer, which filters and focuses light signals to improve signal quality and reduce background noise, integrated with a fluid control device for sample handling on the sensor chip, enhancing detection accuracy and reducing costs and time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external optical detection elements and customized optical path systems are used to detect fluorescence signals, then the detection accuracy is improved, but the device size and cost increase
Solution Approach 1:
The patent integrates the optical detection function directly into the CMOS image sensor chip by fabricating light signal filtering structures and light signal guiding structures on the same substrate as the photodiode array. This merging of optical detection elements with the sensor chip eliminates the need for external optical detection elements and complex optical path systems, thereby reducing device size while maintaining detection accuracy
Solution Approach 2:
The patent transitions from a three-dimensional external optical system to a two-dimensional planar integration on the chip surface. By arranging filtering and guiding structures in the same plane as the photodiode array, the system achieves optical detection functionality without requiring external optical components, thus reducing overall device complexity and size
2Measurement precision
If external optical detection elements and customized optical path systems are used to detect fluorescence signals, then the detection accuracy is improved, but the detection time increases
Solution Approach 1:
The integration of optical detection functions directly on the chip eliminates the time required for light signal transmission through external optical paths. The filtering and guiding structures are positioned immediately adjacent to the photodiode array, enabling direct detection of fluorescence signals without the delays associated with external optical component alignment and signal transmission
3Measurement precision
If a filter structure is used to eliminate background noise, then the signal-to-noise ratio is improved, but the crosstalk noise from adjacent samples is not effectively filtered
Solution Approach 1:
The patent divides the detection space into isolated regions by positioning individual filtering structures and guiding structures over each photodiode. This segmentation prevents light signals from adjacent samples from reaching the wrong photodiode, effectively eliminating crosstalk noise while maintaining high signal-to-noise ratio for each detection channel
Solution Approach 2:
Each filtering and guiding structure is customized for its specific location and function, with filtering structures tailored to block specific wavelengths and guiding structures optimized for their particular geometric requirements. This local optimization ensures effective noise filtering and crosstalk prevention for each detection channel while maintaining overall system performance
4Device complexity
If the integration level is improved by fixing biological substance directly on the image sensor chip, then the device size is reduced, but the signal-to-noise ratio becomes insufficient
Solution Approach 1:
The patent combines miniaturization with enhanced signal-to-noise ratio by integrating filtering and guiding structures directly on the chip. This allows the device to maintain compact size while achieving superior noise filtering performance through the carefully designed optical structures positioned immediately over each photodiode
Solution Approach 2:
The filtering structures utilize composite material layers with different optical properties to achieve wavelength-selective filtering. By stacking materials with complementary filtering characteristics, the system achieves high signal-to-noise ratio in a compact integrated format
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 biosensor significantly reduces background noise and crosstalk, providing more accurate detection results while integrating sample handling and light signal processing on a single chip, thus improving the miniaturization and efficiency of biochemical detection systems.
Implementation Method 1
a light signal filter layer, disposed on the surface of the light sensor pixel, comprising a plurality of laminated layers, wherein each laminated layer comprises two material layers with different refractive indices for filtering other light signal components except for the light signals emitted by the biological material in the incident light signals
Implementation Method 2
a metal nanometer light focusing unit array layer, disposed on the surface of the light signal filter layer, comprising a plurality of metal nanometer light focusing units, and configured to focus the light signals emitted into the metal nanometer light focusing units and emit the same into the light signal filter layer
Implementation Method 3
a grating array layer, disposed on the surface of the metal nanometer light focusing unit array layer, comprising a plurality of micro-gratings, and configured to constrain the incident light signals, so that the incident light signals are emitted into the metal nanometer light focusing unit array layer
Implementation Method 4
a light signal detector for receiving and detecting incident light signals, comprising a light sensor pixel array which comprises a plurality of light sensor pixels
Data Source
AI summary
A biosensor for detecting light signals emitted by a biological material is provided. The biosensor includes a light signal detector which comprises an array of light sensor pixels. The biosensor further includes a light signal filter layer disposed on a surface of the light sensor pixel array, a metal nanometer light focusing unit array layer, a grating array layer which comprises micro-gratings, and a biological material sample bearing area which comprises a plurality of sample gathering units. Each sample gathering unit aligns with one micro-grating and one metal nanometer light focusing unit in the vertical direction, and at least one of the light sensor pixels.