7 results on '"Rossella Iglio"'
Search Results
2. Photonically Encoded Silicone Lenses For Smartphone-Based Microscopy And Imaging In Biology And Nanomedicine
- Author
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Stefano Mariani, Tushar Kumeria, Valentina Robbiano, Michael J. Sailor, Byungji Kim, Rossella Iglio, Giuseppe Barillaro, Antonino A. La Mattina, Pantea Nadimi, and Joanna Wang
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chemistry.chemical_compound ,Silicone ,chemistry ,Microscopy ,Nanomedicine ,Nanotechnology - Abstract
In this work [1], we describe the moldless preparation of a poly(dimethylsiloxane) (PDMS) lens embedding nanostructured porous silicon (PSi) optical components. Casting of uncured PDMS onto a PSi surface shapes a droplet with contact angle easily controllable by tuning of the nanostructure features (i.e., thickness and porosity of PSi). Design of the PSi layer as an optical component (e.g., distributed Bragg reflector, rugate filter, resonant cavity) allows the preparation of lightweight, freestanding PDMS lenses (10 mg mass and 4.7 mm focal length) with embedded optical elements. The fabrication process of the PDMS lens shows high reliability (yield >95%), low-cost (0.01 $), and good flexibility for a wide range of applications. For instance, using a single monolithic lens/filter element self-adhered to a commercial smartphone camera, we demonstrate: the fluorescence imaging and counting of live/dead isolated human cancer cells with high magnification and rejection of the excitation light; the selection of a narrow wavelength band from a fluorescent emission; and the tuning of the color of a white light emitting diode (from red to blue) through shaping of the emission spectrum. [1] S. Mariani et al., Adv. Funct. Mater.2019, 1906836
- Published
- 2020
3. Moldless Printing of Silicone Lenses With Embedded Nanostructured Optical Filters
- Author
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Michael J. Sailor, Byungji Kim, Giuseppe Barillaro, Rossella Iglio, Joanna Wang, Stefano Mariani, Tushar Kumeria, Valentina Robbiano, Pantea Nadimi, and Antonino A. La Mattina
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Diffraction ,Materials science ,Silicon ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,Porous silicon ,fluorescence microscopy ,01 natural sciences ,Article ,law.invention ,Biomaterials ,law ,cell imaging ,Electrochemistry ,Focal length ,nanostructured optical filters ,porous silicon ,silicone micro lenses ,Optical filter ,Photonic crystal ,business.industry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Distributed Bragg reflector ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Lens (optics) ,chemistry ,Optoelectronics ,0210 nano-technology ,business - Abstract
Optical lenses are among the oldest technological innovations (3000 years ago) and they have enabled a multitude of applications in healthcare and in our daily lives. The primary function of optical lenses has changed little over time; they serve mainly as a light-collection (e.g. reflected, transmitted, diffracted) element, and the wavelength and/or intensity of the collected light is usually manipulated by coupling with various external optical filter elements or coatings. This generally results in losses associated with multiple interfacial reflections, and increases the complexity of design and construction. In this work we introduce a change in this paradigm, by integrating both light-shaping and image magnification into a single lens element using a moldless procedure that takes advantage of the physical and optical properties of mesoporous silicon (PSi) photonic crystal nanostructures. Casting of a liquid poly(dimethyl) siloxane (PDMS) pre-polymer solution onto a PSi film generates a droplet with contact angle that is readily controlled by the silicon nanostructure, and adhesion of the cured polymer to the PSi photonic crystal allows preparation of lightweight (10 mg) freestanding lenses (4.7 mm focal length) with an embedded optical component (e.g. optical rugate filter, resonant cavity, distributed Bragg reflector). Our fabrication process shows excellent reliability (yield 95%) and low cost and we expect our lens to have implications in a wide range of applications. As a proof-of-concept, using a single monolithic lens/filter element we demonstrate: fluorescence imaging of isolated human cancer cells with rejection of the blue excitation light, through a lens that is self-adhered to a commercial smartphone; shaping the emission spectrum of a white light emitting diode (LED) to tune the color from red through blue; and selection of a narrow wavelength band (bandwidth 5 nm) from a fluorescent molecular probe.
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- 2019
4. Structural and thermoanalytical characterization of 3D porous PDMS foam materials: The effect of impurities derived from a sugar templating process
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Giuseppe Barillaro, Rossella Iglio, José González-Rivera, Maria Rosaria Tine, and Celia Duce
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Cleaning agent ,Thermogravimetric analysis ,Materials science ,Polymers and Plastics ,TG-FTIR ,X-ray (Micro-CT) microtomography ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Article ,Sugar templating process ,lcsh:QD241-441 ,chemistry.chemical_compound ,lcsh:Organic chemistry ,PDMS ,Thermal stability ,Fourier transform infrared spectroscopy ,Porosity ,chemistry.chemical_classification ,Polydimethylsiloxane ,3D porous network ,Chemistry (all) ,General Chemistry ,Polymer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Thermogravimetry ,chemistry ,Chemical engineering ,0210 nano-technology - Abstract
Polydimethylsiloxane (PDMS) polymers are extensively used in a wide range of research and industrial fields, due to their highly versatile chemical, physical, and biological properties. Besides the different two-dimensional PDMS formulations available, three-dimensional PDMS foams have attracted increased attention. However, as-prepared PDMS foams contain residual unreacted low molecular weight species that need to be removed in order to obtain a standard and chemically stable material for use as a scaffold for different decorating agents. We propose a cleaning procedure for PDMS foams obtained using a sugar templating process, based on the use of two different solvents (hexane and ethanol) as cleaning agents. Thermogravimetry coupled with Fourier Transform Infrared Spectroscopy (TG-FTIR) for the analysis of the evolved gasses was used to characterize the thermal stability and decomposition pathway of the PDMS foams, before and after the cleaning procedure. The results were compared with those obtained on non-porous PDMS bulk as a reference. Micro-CT microtomography and scanning electron microscopy (SEM) analyses were employed to study the morphology of the PDMS foam. The thermogravimetric analysis (TGA) revealed a different thermal behaviour and crosslinking pathway between bulk PDMS and porous PDMS foam, which was also influenced by the washing process. This information was not apparent from spectroscopic or morphological studies and it would be very useful for planning the use of such complex and very reactive systems.
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- 2018
5. Flexible Polydimethylsiloxane Foams Decorated with Multiwalled Carbon Nanotubes Enable Unprecedented Detection of Ultralow Strain and Pressure Coupled with a Large Working Range
- Author
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Lucanos Marsilio Strambini, Rossella Iglio, Stefano Mariani, Giuseppe Barillaro, and Valentina Robbiano
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Materials science ,pressure sensors ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,Multiwalled carbon ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,carbon nanotubes ,flexible sensors ,large working range ,piezoresistivity ,porous PDMS foams ,strain sensors ,ultralow strain/pressure detection ,Materials Science (all) ,law ,General Materials Science ,Composite material ,Porosity ,Polydimethylsiloxane ,Strain (chemistry) ,021001 nanoscience & nanotechnology ,Piezoresistive effect ,Pressure sensor ,0104 chemical sciences ,Working range ,chemistry ,0210 nano-technology - Abstract
Low-cost piezoresistive strain/pressure sensors with large working range, at the same time able to reliably detect ultralow strain (
- Published
- 2018
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6. FLEXIBLE CNT-DECORATED PDMS FOAM ENABLE UNPRECEDENTED DETECTION OF ULTRALOW STRAIN AND PRESSURE COUPLED WITH LARGE WORKING RANGE
- Author
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Rossella Iglio, Stefano Mariani, Valentina Robbiano, Lucanos M. Strambini, and Giuseppe Barillaro
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carbon nanotubes ,flexible sensors ,large working range ,piezoresistivity ,porous PDMS foams ,pressure sensors ,strain sensors ,ultralow strain/pressure detection - Abstract
Realization and characterization of a low cost conductometric pressure and strain sensor with a porous polymeric material decorated with Carbon Nanotubes (CNTs). CNTs, not being covered by the polymer, are anchored to the macroporous PDMS sponge surface and directly accessible, thus increasing sensitivity of electrical charge flow (current) with compressive strain. Realization and characterization of piezoresistive, flexible, three-dimensional (3D) macroporous PDMS (pPDMS) foams with pores of about 500 ?m, decorated with a complex network of pristine multiwalled CNTs (density of 25 mg/cm3 ), enabling reliable and simultaneous detection of ultrasmall strain (0.1%) and pressure (20 Pa) in compression mode, coupled with a large dynamic range (i.e., up to 60% for strai 6 mm displacement and 50 kPa for pressure).
- Published
- 2018
7. Flexible PDMS Foams Decorated with Multi–Walled CNTs for Unprecedented Detection of Ultralow Strain and Pressure Coupled with Large Working Range
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Rossella Iglio, Stefano Mariani, Valentina Robbiano, Lucanos Strambini, and Giuseppe Barillaro
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carbon nanotubes ,large working range ,porous PDMS foams ,flexible sensors ,pressure sensors ,piezoresistivity ,strain sensors ,ultralow strain/pressure detection - Abstract
Over the last years a huge effort has been paid to the development of flexible and wearable strain and pressure sensors for, though not limited to, health care applications. In spite of the tremendous effort paid over the last years, the analysis of the literature on this field points out that it was still unmet the challenge to achieve high performance piezoresistive sensors with simultaneous ultralow limit of detection and large working range both for pressure and strain, able to address both subtle (1Pa-1 kPa) to medium (up to 100 kPa) pressures and ultrasmall (≤0.1%) to large (>50%) strains. In this work, we demonstrate unprecedented simultaneous detection of ultrasmall strain (0.1%) and subtle pressure (20 Pa) coupled with a large working range (up to 60% for strain and 50 kPa for pressure)using piezoelectric, flexible three-dimensional (3D) macroporous PDMS (pPDMS) foams with pores of 500µm decorated with a thin network of pristine multi-walled CNTs. Limit of detection of our sensors are 0.03% for strain (i.e) and 6 Pa for pressure, which corresponds to a minimum detectable displacement of 3 µmover a length of 10 mm and to a minimum detectable force of 0.6 mN over an area of 1 cm2, given that the pPDMS/CNTs foams of this work are cubes of 1 cm in size. Adding to these excellent features, the foams can reliably support deformation up to 6 mm (60% strain) and measure a maximum pressure of about 50 kPa (i.e. a force of 5 N over an area of 1 cm2). In a few words, our foams are able to detect both displacement and pressure produced by a fly (about 70 mg of weight), at the same time being able to measure displacement and pressure produced by an Apple iPad (about 500 g). Remarkably, preparation of our 3D pPDMS/CNTs foams is low-cost and up-scalable. In fact, it is based on simple replica molding of sacrificial sugar templates and subsequent drop-casting of CNT ink drops. We show in the manuscript that the preparation is highly robust in terms of both static and dynamic piezoelectric performance, also for long cycling. Further, by simply changing geometry and size of the sacrificial sugar templates, the foams can be arbitrarily shaped with different areas, ranging from 2 up to 10 cm x 10 cm, and thicknesses, ranging from 1 mm to 10 mm, and geometry tunable from simple element to complex meshes. We envisage the use our flexible, piezoresistive strain/pressure sensors for high-precision personalized healthcare and, more broadly, for wearable applications, though applications to other fields where displacement and pressure need to be monitored with extremely high resolution can be also envisaged. [1] Flexible Polydimethylsiloxane Foams Decorated with Multiwalled Carbon Nanotubes Enable Unprecedented Detection of Ultralow Strain and Pressure Coupled with a Large Working Range, R Iglio, S Mariani, V Robbiano, L Strambini, G Barillaro, ACS Applied Materials & Interfaces 10 (16), 13877-13885 (2018).
- Published
- 2019
- Full Text
- View/download PDF
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