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20 pages, 9296 KiB

Open AccessArticle

An Inexpensive, 3D-Printable, Arduino- and Blu-Ray-Based Confocal Laser and Fluorescent Scanning Microscope

by Justin Loose, Samuel H. Hales, Jonah Kendell, Isaac Cutler, Ryan Ruth, Jacob Redd, Samuel Lino and Troy Munro

Metrology 2025, 5(1), 2; https://doi.org/10.3390/metrology5010002 - 6 Jan 2025

Viewed by 1635

Abstract

There is a growing field that is devoted to developing inexpensive microscopes and measurement devices by leveraging low-cost commercial parts that can be controlled using smartphones or embedded devices, such as Arduino and Raspbery Pi. Examples include the use of Blu-ray optical heads [...] Read more.

There is a growing field that is devoted to developing inexpensive microscopes and measurement devices by leveraging low-cost commercial parts that can be controlled using smartphones or embedded devices, such as Arduino and Raspbery Pi. Examples include the use of Blu-ray optical heads like the PHR-803T to perform cytometry, spinning disc microscopy, and lensless holographic microscopy. The modular or disposable nature of these devices means that they can also be used in contaminating and degrading environments, including radioactive environments, where replacement of device elements can be expensive. This paper presents the development and operation of a confocal microscope that uses the PHR-803T optical device in a Blu-ray reader for both imaging and detection of temperature variations with between 1.5 and 15 µm resolution. The benefits of using a PHR-803T confocal system include its relatively inexpensive design and the accessibility of the components that are used in its construction. The design of this scanning confocal thermal microscope (SCoT) was optimized based on cost, modularity, portability, spatial resolution, and ease of manufacturability using common tools (e.g., drill press, 3D printer). This paper demonstrated the ability to resolve microscale features such as synthetic spider silk and measure thermal waves in stainless steel using a system requiring <USD 1000 in material costs. Full article

(This article belongs to the Special Issue Advancements in Optical Measurement Devices and Technologies)

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21 pages, 3468 KiB

Open AccessReview

Multi-Illumination Single-Holographic-Exposure Lensless Fresnel (MISHELF) Microscopy: Principles and Biomedical Applications

by José Ángel Picazo-Bueno, Martín Sanz, Luis Granero, Javier García and Vicente Micó

Sensors 2023, 23(3), 1472; https://doi.org/10.3390/s23031472 - 28 Jan 2023

Cited by 6 | Viewed by 2909

Abstract

Lensless holographic microscopy (LHM) comes out as a promising label-free technique since it supplies high-quality imaging and adaptive magnification in a lens-free, compact and cost-effective way. Compact sizes and reduced prices of LHMs make them a perfect instrument for point-of-care diagnosis and increase [...] Read more.

Lensless holographic microscopy (LHM) comes out as a promising label-free technique since it supplies high-quality imaging and adaptive magnification in a lens-free, compact and cost-effective way. Compact sizes and reduced prices of LHMs make them a perfect instrument for point-of-care diagnosis and increase their usability in limited-resource laboratories, remote areas, and poor countries. LHM can provide excellent intensity and phase imaging when the twin image is removed. In that sense, multi-illumination single-holographic-exposure lensless Fresnel (MISHELF) microscopy appears as a single-shot and phase-retrieved imaging technique employing multiple illumination/detection channels and a fast-iterative phase-retrieval algorithm. In this contribution, we review MISHELF microscopy through the description of the principles, the analysis of the performance, the presentation of the microscope prototypes and the inclusion of the main biomedical applications reported so far. Full article

(This article belongs to the Collection Biomedical Imaging and Sensing)

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18 pages, 3042 KiB

Open AccessReview

Resolution and Contrast Enhancement for Lensless Digital Holographic Microscopy and Its Application in Biomedicine

by Duofang Chen, Lin Wang, Xixin Luo, Hui Xie and Xueli Chen

Photonics 2022, 9(5), 358; https://doi.org/10.3390/photonics9050358 - 19 May 2022

Cited by 15 | Viewed by 6413

Abstract

An important imaging technique in biomedicine, the conventional optical microscopy relies on relatively complicated and bulky lens and alignment mechanics. Based on the Gabor holography, the lensless digital holographic microscopy has the advantages of light weight and low cost. It has developed rapidly [...] Read more.

An important imaging technique in biomedicine, the conventional optical microscopy relies on relatively complicated and bulky lens and alignment mechanics. Based on the Gabor holography, the lensless digital holographic microscopy has the advantages of light weight and low cost. It has developed rapidly and received attention in many fields. However, the finite pixel size at the sensor plane limits the spatial resolution. In this study, we first review the principle of lensless digital holography, then go over some methods to improve image contrast and discuss the methods to enhance the image resolution of the lensless holographic image. Moreover, the applications of lensless digital holographic microscopy in biomedicine are reviewed. Finally, we look forward to the future development and prospect of lensless digital holographic technology. Full article

(This article belongs to the Special Issue Spectroscopic Imaging)

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17 pages, 5051 KiB

Open AccessArticle

Design, Calibration, and Application of a Robust, Cost-Effective, and High-Resolution Lensless Holographic Microscope

by Jose Angel Picazo-Bueno, Karina Trindade, Martin Sanz and Vicente Micó

Sensors 2022, 22(2), 553; https://doi.org/10.3390/s22020553 - 11 Jan 2022

Cited by 16 | Viewed by 3834

Abstract

Lensless holographic microscope (LHM) is an emerging very promising technology that provides high-quality imaging and analysis of biological samples without utilizing any lens for imaging. Due to its small size and reduced price, LHM can be a very useful tool for the point-of-care [...] Read more.

Lensless holographic microscope (LHM) is an emerging very promising technology that provides high-quality imaging and analysis of biological samples without utilizing any lens for imaging. Due to its small size and reduced price, LHM can be a very useful tool for the point-of-care diagnosis of diseases, sperm assessment, or microfluidics, among others, not only employed in advanced laboratories but also in poor and/or remote areas. Recently, several LHMs have been reported in the literature. However, complete characterization of their optical parameters remains not much presented yet. Hence, we present a complete analysis of the performance of a compact, reduced cost, and high-resolution LHM. In particular, optical parameters such as lateral and axial resolutions, lateral magnification, and field of view are discussed into detail, comparing the experimental results with the expected theoretical values for different layout configurations. We use high-resolution amplitude and phase test targets and several microbeads to characterize the proposed microscope. This characterization is used to define a balanced and matched setup showing a good compromise between the involved parameters. Finally, such a microscope is utilized for visualization of static, as well as dynamic biosamples. Full article

(This article belongs to the Special Issue Three-Dimensional (3D) Biophotonics Sensing and Reconstruction towards Biomedical Research)

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13 pages, 3284 KiB

Open AccessFeature PaperArticle

A Compact Raster Lensless Microscope Based on a Microdisplay

by Anna Vilà, Sergio Moreno, Joan Canals and Angel Diéguez

Sensors 2021, 21(17), 5941; https://doi.org/10.3390/s21175941 - 3 Sep 2021

Cited by 9 | Viewed by 3406

Abstract

Lensless microscopy requires the simplest possible configuration, as it uses only a light source, the sample and an image sensor. The smallest practical microscope is demonstrated here. In contrast to standard lensless microscopy, the object is located near the lighting source. Raster optical [...] Read more.

Lensless microscopy requires the simplest possible configuration, as it uses only a light source, the sample and an image sensor. The smallest practical microscope is demonstrated here. In contrast to standard lensless microscopy, the object is located near the lighting source. Raster optical microscopy is applied by using a single-pixel detector and a microdisplay. Maximum resolution relies on reduced LED size and the position of the sample respect the microdisplay. Contrarily to other sort of digital lensless holographic microscopes, light backpropagation is not required to reconstruct the images of the sample. In a mm-high microscope, resolutions down to 800 nm have been demonstrated even when measuring with detectors as large as 138 μm × 138 μm, with field of view given by the display size. Dedicated technology would shorten measuring time. Full article

(This article belongs to the Special Issue Advanced CMOS Sensors and Applications)

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19 pages, 5180 KiB

Open AccessReview

Speckle-Correlation Scattering Matrix Approaches for Imaging and Sensing through Turbidity

by YoonSeok Baek, KyeoReh Lee, Jeonghun Oh and YongKeun Park

Sensors 2020, 20(11), 3147; https://doi.org/10.3390/s20113147 - 2 Jun 2020

Cited by 12 | Viewed by 6352

Abstract

The development of optical and computational techniques has enabled imaging without the need for traditional optical imaging systems. Modern lensless imaging techniques overcome several restrictions imposed by lenses, while preserving or even surpassing the capability of lens-based imaging. However, existing lensless methods often [...] Read more.

The development of optical and computational techniques has enabled imaging without the need for traditional optical imaging systems. Modern lensless imaging techniques overcome several restrictions imposed by lenses, while preserving or even surpassing the capability of lens-based imaging. However, existing lensless methods often rely on a priori information about objects or imaging conditions. Thus, they are not ideal for general imaging purposes. The recent development of the speckle-correlation scattering matrix (SSM) techniques facilitates new opportunities for lensless imaging and sensing. In this review, we present the fundamentals of SSM methods and highlight recent implementations for holographic imaging, microscopy, optical mode demultiplexing, and quantification of the degree of the coherence of light. We conclude with a discussion of the potential of SSM and future research directions. Full article

(This article belongs to the Special Issue Lensless Imaging and Computational Sensing)

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13 pages, 5275 KiB

Open AccessArticle

Continuous Live-Cell Culture Imaging and Single-Cell Tracking by Computational Lensfree LED Microscopy

by Gregor Scholz, Shinta Mariana, Agus Budi Dharmawan, Iqbal Syamsu, Philipp Hörmann, Carsten Reuse, Jana Hartmann, Karsten Hiller, Joan Daniel Prades, Hutomo Suryo Wasisto and Andreas Waag

Sensors 2019, 19(5), 1234; https://doi.org/10.3390/s19051234 - 11 Mar 2019

Cited by 22 | Viewed by 9282

Abstract

Continuous cell culture monitoring as a way of investigating growth, proliferation, and kinetics of biological experiments is in high demand. However, commercially available solutions are typically expensive and large in size. Digital inline-holographic microscopes (DIHM) can provide a cost-effective alternative to conventional microscopes, [...] Read more.

Continuous cell culture monitoring as a way of investigating growth, proliferation, and kinetics of biological experiments is in high demand. However, commercially available solutions are typically expensive and large in size. Digital inline-holographic microscopes (DIHM) can provide a cost-effective alternative to conventional microscopes, bridging the gap towards live-cell culture imaging. In this work, a DIHM is built from inexpensive components and applied to different cell cultures. The images are reconstructed by computational methods and the data are analyzed with particle detection and tracking methods. Counting of cells as well as movement tracking of living cells is demonstrated, showing the feasibility of using a field-portable DIHM for basic cell culture investigation and bringing about the potential to deeply understand cell motility. Full article

(This article belongs to the Special Issue Eurosensors 2018 Selected Papers)

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5 pages, 1023 KiB

Open AccessProceeding Paper

Continuous Live-Cell Culture Monitoring by Compact Lensless LED Microscopes

by Gregor Scholz, Shinta Mariana, Iqbal Syamsu, Agus Budi Dharmawan, Torben Schulze, Kai Mattern, Philipp Hörmann, Jana Hartmann, Andreas Dietzel, Ingo Rustenbeck, Karsten Hiller, Joan Daniel Prades, Andreas Waag and Hutomo Suryo Wasisto

Proceedings 2018, 2(13), 877; https://doi.org/10.3390/proceedings2130877 - 5 Dec 2018

Cited by 3 | Viewed by 3228

Abstract

A compact lensless microscope comprising a custom-made LED engine and a CMOS imaging sensor has been developed for live-cell culture imaging inside a cell incubator environment. The imaging technique is based on digital inline-holographic microscopy, while the image reconstruction is carried out by [...] Read more.

A compact lensless microscope comprising a custom-made LED engine and a CMOS imaging sensor has been developed for live-cell culture imaging inside a cell incubator environment. The imaging technique is based on digital inline-holographic microscopy, while the image reconstruction is carried out by angular spectrum approach with a custom written software. The system was tested with various biological samples including immortalized mouse astrocyte cells inside a petri dish. Besides the imaging possibility, the capability of automated cell counting and tracking could be demonstrated. By using image sensors capable of video frame rate, time series of cell movement can be captured. Full article

(This article belongs to the Proceedings of EUROSENSORS 2018)

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5 pages, 518 KiB

Open AccessProceeding Paper

Artificial Neural Networks for Automated Cell Quantification in Lensless LED Imaging Systems

by Agus Budi Dharmawan, Gregor Scholz, Shinta Mariana, Philipp Hörmann, Igi Ardiyanto, Sunu Wibirama, Jana Hartmann, Joan Daniel Prades, Karsten Hiller, Andreas Waag and Hutomo Suryo Wasisto

Proceedings 2018, 2(13), 989; https://doi.org/10.3390/proceedings2130989 - 29 Nov 2018

Cited by 1 | Viewed by 2386

Abstract

Cell registration by artificial neural networks (ANNs) in combination with principal component analysis (PCA) has been demonstrated for cell images acquired by light emitting diode (LED)-based compact holographic microscopy. In this approach, principal component analysis was used to find the feature values from [...] Read more.

Cell registration by artificial neural networks (ANNs) in combination with principal component analysis (PCA) has been demonstrated for cell images acquired by light emitting diode (LED)-based compact holographic microscopy. In this approach, principal component analysis was used to find the feature values from cells and background, which would be subsequently employed as neural inputs into the artificial neural networks. Image datasets were acquired from multiple cell cultures using a lensless microscope, where the reference data was generated by a manually analyzed recording. To evaluate the developed automatic cell counter, the trained system was assessed on different data sets to detect immortalized mouse astrocytes, exhibiting a detection accuracy of ~81% compared with manual analysis. The results show that the feature values from principal component analysis and feature learning by artificial neural networks are able to provide an automatic approach on the cell detection and registration in lensless holographic imaging. Full article

(This article belongs to the Proceedings of EUROSENSORS 2018)

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