Conference proceedings talk, Frontiers in Optics: Proceedings Frontiers in Optics + Laser Science 2023, FiO, LS 2023,
We demonstrate ultra-fast 25.6kHz imaging on a conventional epi-fluorescent sCMOS camera setup, surpassing the compromise between field of view (FOV) and imaging speed via introducing a custom fiber-optic bundle without significant complexity or cost.
Conference proceedings talk, Frontiers in Optics: Proceedings Frontiers in Optics + Laser Science 2023, FiO, LS 2023,
We propose multifocal scanning microscopy for super-resolution fluorescence imaging to achieve simultaneous multi-color acquisition. Our system achieves two-fold improvement over the diffraction limit for both emission wavelengths through imaging phantoms and HeLa cells.
Conference proceedings talk, Frontiers in Optics: Proceedings Frontiers in Optics + Laser Science 2023, FiO, LS 2023,
Image scanning microscopy allows detailed 3D imaging but has a complex setup. Our 3D multifocal scanning microscope doubles resolution, provides optical sectioning, and enhances contrast with a simplified setup making it promising for digital pathology.
Conference proceedings talk, 3D Image Acquisition and Display: Technology, Perception and Applications in Proceedings Optica Imaging Congress, 3D, COSI, DH, FLatOptics, IS, pcAOP 2023,
Fluorescence imaging flow cytometry (IFC) has enriched both structural and functional information for diverse applications. We developed portable light-sheet optofluidic microscopy equipping simultaneous multicolor acquisition for high-throughput and multicolor 3D florescence IFC application.
Conference proceedings talk, Frontiers in Optics: Proceedings Frontiers in Optics + Laser Science 2023, FiO, LS 2023,
In fluorescence microscopy, the quality of the acquired images determines the extent of observable biological phenomena. To address the different noise sources degrading these images, we introduce a model-based framework compatible with several microscopy systems independently from the detector used.
Conference proceedings talk, Frontiers in Optics: Proceedings Frontiers in Optics + Laser Science 2023, FiO, LS 2023,
We propose a denoising-sparse decomposition method for Fourier light-field microscopy to separate signals with different periodicity in complex biological samples. This process allows for enhanced volumetric reconstruction and accurate image analysis.
Conference proceedings talk, 3D Image Acquisition and Display: Technology, Perception and Applications in Proceedings Optica Imaging Congress, 3D, COSI, DH, FLatOptics, IS, pcAOP 2023,
We developed a new 3D imaging flow cytometer with microfluidics and high-resolution light-field microscopy for single-cell studies. We demonstrated a near-diffraction-limited spatial resolution and a throughput of up to 10,000 objects per second.
Conference proceedings talk, Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing XXIX,
Conference proceedings talk, Single Molecule Spectroscopy and Superresolution Imaging XV,
A great interest in high-throughput fluorescence microscopy for biological and medical imaging has led to the flourishing of new imaging methods where the sample is quickly scanned through the optics. Optofluidic microscopes use fluids' properties as an additional degree of freedom for optical detection and microfluidics to perform simple and low-cost object manipulation. Even though several devices have been optimized for fluorescence-based imaging, these systems can rarely resolve sub-micron details, posing a limit to the structures that can be studied. An exception is represented by systems developed for particle detection, which are capable to quantify protein expression and analyze small molecules even at nanoscale resolution. However, in this case, high resolution requires a low emitter density and it cannot be used to visualize densely packed structures such as membranes and organelles. Hence, we have developed a system for sub-diffractionlimited optofluidic scanning microscopy (OSM) that uses the optofluidics paradigm to extract the inherent super-resolution information of a confocal system. OSM uses the optofluidic flow scanning scheme and a multifocal illumination pattern to obtain resolution doubling with minimal system complexity. In addition, it does not require any mechanical part for the scanning, so that it can be readily adapted to different levels of integration from commercial microscopes to on-chip configurations. This makes our system the most viable configuration for super-resolution optofluidics, being both suitable for continuous flow scanning and compatible with on-chip configurations through the adoption of integrated optics, like custom micro-lenses or Fresnel zone plates. Finally, we demonstrate how the same concept can be adapted to digital slide scanners for super-resolution whole slide imaging.
Conference proceedings talk, Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XX,
Conference proceedings talk, Optical Methods for Inspection, Characterization, and Imaging of Biomaterials V,
Conference proceedings talk, Optics InfoBase Conference Papers,
Live cell fluorescence imaging have enriched image-based screening applications with microwell plates. Here, we propose a portable system by synchronizing miniaturized microscopies and show the performance of live cell imaging inside an incubator.
Conference proceedings talk, Optics InfoBase Conference Papers,
CMOS cameras are very appealing for fluorescence microscopy but they suffer from high readout noise and fixed-pattern noise. We propose a non-iterative, fast, and unsupervised algorithm that erases camera-related noise without losing the quantitative information of fluorescence signal. Finally, we demonstrate the performance of the algorithm using different sensors, from low-cost CMOS chips to high-end sCMOS cameras.
Conference proceedings talk, Optics InfoBase Conference Papers,
Here we design a compact, portable and cost-effective holographic microscope based on the concept of holographic microscope slide. We developed a wavefront division holographic interferometer deployable for in-situ environmental monitoring and point-of care diagnostics.
Conference proceedings talk, Optics InfoBase Conference Papers,
The miniaturized one-photon epi-fluorescence microscopy (miniscopy) has emerged as a powerful tool for in vivo functional brain imaging. Here, we report a computational method to improve the image quality of miniscopy.
Conference proceedings talk, Optics InfoBase Conference Papers,
Unique feature of DH for implementing numerical scanning of the reconstruction distance is used to characterize near-field propagation properties of phase structures imprinted into photorefractive Lithium Niobate crystals by biolenses as Red Blood Cells.
Conference proceedings talk, Conference Proceedings of the Society for Experimental Mechanics Series,
Digital holographic microscopy (DHM) has become a technique utilized widely for sample inpection, having many applications in different fields of science and technology. The capability for recovering the complex amplitude distribution scattered by the sample permits numerical refocus after acquisition and quantitative phase imaging. These are two of the features that make DHM a very versatile microscopy technique. The standard DHM system is based on a Mach– Zehnder interferometer that can be configured for operating in transmission or reflection modes, working in either the in-line or off-axis architecture. With the benefit of such special characteristics, DHM is used in basic research as much in the industry. Here we review some of the recent advancements for the label-free inspection of biological samples and the study of thin films.
Conference proceedings talk, Optics InfoBase Conference Papers,
sCMOS cameras are very appealing for fluorescence microscopy but they suffer from high readout noise. We propose a non-iterative, fast, and unsupervised algorithm that erases sCMOS noise without losing the quantitative information of fluorescence signal.
Conference proceedings talk, Label-free Biomedical Imaging and Sensing (LBIS) 2019,
Probiotics are microbial species that have been demonstrated to confer benefits to health. In recent years, the use of probiotics in food and health has increased enormously. A sufficient concentration of probiotics in the intestine acts against pathologies such as obesity, diabetes, etc. However, if probiotics are not able to maintain their viability during their transit through the gastro-intestinal apparatus, they cannot act to enhance the immune system. Hence, protection and preservation of probiotics are essential to both food industry and in pharmaceutics. Microencapsulation is one of the most common methods of preservation, applicable to several biological matrices, including probiotics. Whenever food products or pharmaceutical formulations contain microencapsulated probiotics, it is important to quantify the effectiveness of micro-encapsulation as a microbial protection system over the time, e.g. during the shelf life of a functional product containing encapsulated probiotics, conserved in the supermarket, and during gastro-intestinal transit. Here we use bio-speckle decorrelation as a tool for the rapid assessment of microencapsulation effectiveness. Although speckles are often thought as a noise to get rid of, they represent a precious source of information, increasing the sensitivity of image sensors based on coherent illumination. Such information is exploitable to characterize bacterial dynamics in a fast and simple way suitable for applications in food science and industry. Through bio-speckle decorrelation, we quantify the shelf-time of alginate-encapsulated Lactobacillus rhamnosus and Lactobacillus plantarum probiotic bacteria and their survival rate under simulated gastro-intestinal conditions. © 2019 SPIE.
Conference proceedings talk, Optics InfoBase Conference Papers,
Computation tools allow to enforce 3D imaging through thus making digital holography a powerful metrology instrument in science and technology of liquid bubbles and films.
Conference proceedings talk, Progress in Biomedical Optics and Imaging - Proceedings of SPIE,
© COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only. In global healthcare and point-of-care diagnostics there is an increasing request of medical equipment with devices able to provide fast and reliable testing for clinical diagnosis. In developing countries that lack of adequate facilities, this need is even more urgent. Lab-on-a-Chip devices have undergone a great growth during the last decade, supported by optical imaging techniques more and more refined. Here we present recent progresses in developing imaging tools based on holographic microscopy that can be very useful when applied into bio-microfluidics. Digital Holography (DH) is label-free, non-invasive, potentially high-throughput and, above all, quantitative. We show the recent advancements of DH in transmission microscopy mode, when this is applied to microfluidics to yield 3D imaging capabilities. Holographic flow cytometry through quantitative phase imaging and in-flow tomography for the analysis and manipulation of micro-particles and cells will be shown [1-3]. Medical diagnostic applications based on DH will be also shown. Moreover, we present a portable common-path holographic microscope embedded onboard a microfluidic device that paves the way to the application of DH on the field [4].
Conference proceedings talk, Proceedings of SPIE - The International Society for Optical Engineering,
© COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only. Bacteria are often associated with the insurgence of diseases and many efforts have been made to develop methods for accurate identification of bacteria in food for industry and new generation smart farms. On the other hand, there is a wide category of "good" bacteria that are used in food and pharmaceutic industry. In particular, probiotics are microbial species that have been demonstrated to confer benefits to health, acting against pathologies such as obesity, diabetes, etc. Probiotics have to maintain their viability during their transit through the gastro-intestinal apparatus in order to act to enhance the immune system. The use of alginate microcapsules is one of the most common methods of preservation, applicable to several biological matrices, including probiotics. Here we use bio-speckle decorrelation as a tool for the rapid assessment of microencapsulation effectiveness. Although speckles are often thought as a source of noise, these can be fruitfully used to increase the sensitivity of coherent imaging sensors. Thus, it is possible to characterize bacteria motion and to use it as a contrast agent for applications in food science and industry. Through bio-speckle decorrelation, we detect the presence of bacteria in food without any chemical analysis. Moreover, we quantify the shelf-time of alginate-encapsulated Lactobacillus rhamnosus and Lactobacillus plantarum probiotic bacteria and their survival rate under simulated gastro-intestinal conditions.
Conference proceedings talk, Optics and Biophotonics in Low-Resource Settings V,
Conference proceedings talk, Optics InfoBase Conference Papers,
A holographic 3D particle tracking method based on numerical diffraction propagation and correlation recognition is applied on film drainage analysis and red blood cells counting. Location of particles in different depth layers are revealed accurately.
Conference proceedings talk, MARSS 2018 - International Conference on Manipulation, Automation and Robotics at Small Scales,
The thickness of thin liquid films is of great interest to industrial processes and life science. Here we propose a holographic system for the evaluation of the 3D topography and thickness of evolving thin liquid film.
Conference proceedings talk, Speckle 2018: VII International Conference on Speckle Metrology,
Digital holographic microscopy (DHM) has proved to be a powerful imaging tool for identifying, analysing and reconstructing the 3D shape of cells and small organisms in their natural environment. In fact, DHM has the advantage, compared to other imaging techniques, to be a non-intrusive, non-destructive and label-free method for in situ measurements. This makes holography the most suitable tool for underwater imaging, where many of the species under investigation are very fragile and can be damaged. In particular, we built up an optofluidic platform based on DHM able to perform such analysis in microfluidic environment, i.e. in dynamic conditions and also in case of a turbid medium. In this work, we take advantage of this technique to identify, sort and reconstruct the morphology of different classes of microplastics (e.g. PVC, PET, PP, etc.) dispersed in water, which are among the major pollutants in the ocean, and to provide an effective assessment of their abundance. By adopting special algorithms for numerical processing of the acquired images, we try to separate the plastics from other materials, such as organic debris (shell fragments, animals parts, diatoms, etc.) and other items (metal paint coatings, tar, glass, etc.). © 2018 SPIE.
Conference proceedings talk, ACS Applied Materials and Interfaces,
Electrohydrodynamic jetting is emerging as a successful technique for printing inks with resolutions well beyond those offered by conventional inkjet printers. However, the variety of printable inks is still limited to those with relatively low viscosities (typically <20 mPa s) due to nozzle clogging problems. Here, we show the possibility of printing ordered microdots of high viscous inks such as poly(lactic-co-glycolic acid) (PLGA) by exploiting the spontaneous breakup of a thin fiber generated through nozzle-free pyro-electrospinning. The PLGA fiber is deposited onto a partially wetting surface, and the breakup is achieved simply by applying an appropriate thermal stimulation, which is able to induce polymer melting and hence a mechanism of surface area minimization due to the Plateau-Rayleigh instability. The results show that this technique is a good candidate for extending the printability at the microscale to high viscous inks, thus extending their applicability to additional applications, such as cell behavior under controlled morphological constraints.
Conference proceedings talk, Optics InfoBase Conference Papers,
The state-of-the-art fabrication of micro-optics gives the opportunity to embed complex optical devices in small spaces. Here we show a compact interferometer on a commercial plastic chip for off-axis Digital Holography microscopy.
Conference proceedings talk, Speckle 2018: VII International Conference on Speckle Metrology,
Conference proceedings talk, Optics InfoBase Conference Papers,
Here we show the versatility of Digital Holography Microscopy for the development of innovative systems for quantitative phase imaging of Total Internal Reflection.
Conference proceedings talk, Optical Methods for Inspection, Characterization, and Imaging of Biomaterials III,
© COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only. In this paper, we propose digital holography in transmission configuration as an effective method to measure the time-dependent thickness of polymeric films during bubble blowing. We designed a complete set of experiments to measure bubble thickness, including the evaluation of the refractive index of the polymer solution. We report the measurement of thickness distribution along the film during the bubble formation process until the bubbleâ€s rupture. Based on those data, the variation range and variation trend of bubble film thickness are clearly measured during the process of expansion to fracture is indicated.
Conference proceedings talk, Optics InfoBase Conference Papers,
We designed a LoC with embedded optofluidic holographic microscopy capabilities. Object flow allows unlimited FoV microscopy of samples in a liquid volume. High-throughput counting and 3D tracking of RBCs is demonstrated.
Conference proceedings talk, Optical Methods for Inspection, Characterization, and Imaging of Biomaterials III,
The development of tools for rapid food quality inspection is a highly pursued goal. These could be valuable devices to be used by food producers in factories or the customers themselves in specific installations at the marketplace. Here we show how speckle patterns in coherent imaging systems can be can be employed as indicators of the presence of bacteria colonies contaminating food or water. Speckle decorrelation is induced by the self-propelling movement of these organisms when they interact with coherent light. Hence, their presence can be detected using a simple setup in a condition in which the single element cannot be imaged, but the properties of the ensemble can be exploited. Thanks to the small magnification factor we set, our system can inspect a large Field-of-View (FoV). We show the possibility to discriminate between fresh and contaminated food, thus paving the way to the rapid food quality testing by consumers at the marketplace.
Conference proceedings talk, Quantitative Phase Imaging II,
? 2016 SPIE.We built and tested a Holographic Surface Plasmon Resonance (HoloSPR) objective-based microscope for simultaneous amplitude-contrast and phase-contrast Surface Plasmon Resonance imaging (SPRi). SPRi is a widely spread tool for label-free detection of changes in refractive index and concentration, as well as mapping of thin films. However, to obtain quantitative data of thin film thickness, usually scanning techniques have to be employed. Thanks to the simultaneous detection of amplitude and phase, we show that HoloSPRi provides a versatile imaging tool for high-throughput SPR detection, which yields, moreover, the possibility of non-scanning quantitative measurements of thin film thickness.
Conference proceedings talk, Ophthalmic Technologies XXVI, 2016 SPIE
As the world's population ages, cataract-induced visual dysfunction and blindness is on the increase. This is a significant global problem. The most common symptoms of cataracts are glared and blurred vision. Usually, people with cataract have trouble seeing and reading at distance or in low light and also their color perception is altered. Furthermore, cataract is a sneaky disease as it is usually a very slow but progressive process, which creates adaptation so that patients find it difficult to recognize. All this can be very difficult to explain, so we built and tested an optical device to help doctors giving comprehensive answers to the patients"? symptoms. This device allows visualizing how cataract impairs vision mimicking the optical degradation of the crystalline related cataracts. This can be a valuable optical tool for medical education as well as to provide a method to illustrate the patients how cataract progression process will affect their vision.
Conference proceedings talk, Optical Components and Materials XI,
Novel and intriguing lithographic approaches based on instabilities of liquid polymers and electro-hydro-dynamic at nanoscale have been developed. The unusual fabrication methods were aimed at fabricating 3D polymeric microstructures. A variety of microstructures were fabricated and tested for applications in different fields.
Conference proceedings talk, Micro-Optics 2014,
In the case of light emitting semiconducting polymers, different techniques have been used for the fabrication of electroluminescent devices. Experiments and characterizations have been carried out at different operating voltages and for voltage dependent emission color also combining the processability of organic materials with efficient luminescence displayed by inorganic nanocrystals (NCs). In fact, the experimental perspective to disperse emitting colloidal NCs into polymers has allowed to further engineer hybrid organic-inorganic materials introducing innovative functionalities as for instance photoluminescence conversion capabilities. This has proved of great interest for novel applications such as the fabrication of photonic crystals and, notably, of innovative solar cells showing enhanced efficiency. Here we report on the fabrication of novel active micro-optical elements made by a mixture of rod-shaped inorganic NCs dispersed into poly-dimethylsiloxane. 2014 SPIE.
Conference proceedings talk, AAPP Atti della Accademia Peloritana dei Pericolanti, Classe di Scienze Fisiche, Matematiche e Naturali,
We report a new technique to measure direction and amplitude of electric felds generated by microelectrodes embedded in polar liquid environment, as often used in microfuidic devices. The method is based on optical tweezers which act as sensitive force transducer while a trapped charged microsphere behaves as a probe. When an electric feld is applied the particles moves from its equilibrium position and fnishes in a new equilibrium position where electric and optical forces are balanced.A trapped bead is moved to explore the electric feld in a wide region around the microelectrodes. In such way maps of electric felds with high spatial resolution can be reconstructed even for complex electrode geometries where numerical simulation approaches can fail. Experimental results are compared with calculations based on fnite element analysis simulation. © 2011 by the Author(s); licensee Accademia Peloritana dei Pericolanti, Messina, Italy.