On-Chip 4D Lightfield Microscope Using Plasmonic Lenses

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Solution Overview

Problem

Current on-chip lensless microscope systems face challenges in achieving high resolution, low-cost, label-free bio-detection, increased sensitivity, and specificity, particularly in resource-poor settings, where biological samples are limited and require sensitive, accurate detection with minimal sample volume.

Innovation Solution

An on-chip optofluidic microscope system integrating plasmonic lenses, microfluidic devices, and CMOS image sensor arrays, capable of generating 4D images through computational photography, allowing for improved resolution, low-cost, label-free bio-detection, and increased sensitivity and specificity by manipulating viewpoint and depth of field post-image capture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional lensless microscope systems are used, then device complexity is reduced, but imaging resolution deteriorates

Engineering Contradiction:
Improveimaging resolutionVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The aperture array is segmented into multiple discrete apertures arranged in specific patterns (e.g., hexagonal, square) across the imaging plane. Each aperture captures light from different angular directions, and the segmented aperture patterns are computationally reconstructed to achieve super-resolution imaging beyond the diffraction limit of individual apertures

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from conventional 2D imaging to 4D light field imaging by capturing not only spatial information (x, y) but also angular information (θ, φ) through the aperture array. This additional dimensional information enables computational refocusing, depth mapping, and super-resolution reconstruction without requiring complex optical lenses

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If label-free bio-detection is implemented, then cost is reduced, but detection sensitivity deteriorates

Engineering Contradiction:
Improvedetection sensitivityVSAvoidcost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The system changes the detection parameter from intensity-based single-point measurement to spatial-frequency-based multi-aperture measurement. By analyzing the interference patterns and light field distributions across multiple apertures, the system achieves enhanced sensitivity to refractive index changes caused by biological samples without requiring fluorescent or radioactive labels

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system replaces complex mechanical labeling and detection mechanisms with computational optical processing. Instead of using physical labels to enhance contrast, the system uses algorithms to extract biological information from the raw light field data captured by the aperture array, achieving label-free detection with high sensitivity

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

3Manufacturing precision

If computational photography is used, then imaging resolution is improved, but processing time increases

Engineering Contradiction:
Improveimaging resolutionVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The aperture array is pre-configured with optimized patterns (e.g., hexagonal, square, or random distributions) that are designed to maximize information capture for subsequent computational reconstruction. This preliminary structural design enables faster and more accurate image reconstruction algorithms by ensuring optimal sampling of the light field from different angles

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system captures multiple redundant views of the same sample through the aperture array, creating multiple copies of the light field information from different angular perspectives. These redundant copies are then computationally integrated and fused to produce a single high-resolution image, allowing for error correction and enhanced detail recovery

Inventive Principle:
Principle #26Copying

4Measurement precision

If 4D light field imaging is implemented, then detection specificity is improved, but device complexity increases

Engineering Contradiction:
Improvedetection specificityVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The aperture array serves multiple functions simultaneously: it acts as a spatial sampler, an angular encoder, a depth mapper, and a resolution enhancer. This multi-functional design achieves 4D light field imaging and super-resolution capabilities without requiring separate optical components for each function, thereby limiting the increase in device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 system provides high-resolution imaging, reduced false negatives and positives, and enables cost-effective, automated bio-detection, suitable for point-of-care diagnostics in resource-poor settings, with the ability to analyze multiple samples in parallel and adapt to different diseases using disposable microfluidic chips.

Implementation Method 1

integrating plasmonic lenses, microfluidic devices, and CMOS image sensor arrays

Methodology Applied
Scientific EffectPlasmonics:

Implementation Method 2

integrating plasmonic lenses, microfluidic devices, and CMOS image sensor arrays

Methodology Applied
Scientific EffectMicrofluidics:

Implementation Method 3

integrating plasmonic lenses, microfluidic devices, and CMOS image sensor arrays

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 4

Raskar et al., U.S. Pat. No. 7,792,423, for a 4D Light Field Camera, discloses a camera that acquires a 4D light field of a scene by modulating the 4D light field before it is sensed

Methodology Applied
Scientific EffectDiffraction: Diffraction

Data Source

PatentUS9568723B2On-chip 4D lightfield microscope
Publication Date: 2017.02.14 COUNCIL FOR SCI IND RES
  • US9568723B2 patent drawing
  • US9568723B2 patent drawing
  • US9568723B2 patent drawing

AI summary

The present invention extends on-chip lensless microscope systems (10), including optofluidic microscope (OFMs) and holographic imaging microscopes to incorporate computational photography principles. A LF-OFM system 10 includes at least one plasmonic lens (50) with apertures (38), at least one microfluidic channel (28), and an image sensor array (24). The system (10) is capable of generating an image through computational photography.