| 1. |
- Casalinuovo, Silvia, et al.
(author)
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3D-Printed Face Mask with Integrated Sensors as Protective and Monitoring Tool
- 2023
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In: Sensors and Microsystems. - Cham : Springer Nature Switzerland. - 9783031257087 - 9783031257063
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Conference paper (peer-reviewed)abstract
- The outbreak of the recent Covid-19 pandemic changed many aspects of our daily life, such as the constant wearing of face masks as protection from virus transmission risks. Furthermore, it exposed the healthcare system’s fragilities, showing the urgent need to design a more inclusive model that takes into account possible future emergencies, together with population’s aging and new severe pathologies. In this framework, face masks can be both a physical barrier against viruses and, at the same time, a telemedical diagnostic tool. In this paper, we propose a low-cost, 3D-printed face mask able to protect the wearer from virus transmission, thanks to internal FFP2 filters, and to monitor the air quality (temperature, humidity, CO2) inside the mask. Acquired data are automatically transmitted to a web terminal, thanks to sensors and electronics embedded in the mask. Our preliminary results encourage more efforts in these regards, towards rapid, inexpensive and smart ways to integrate more sensors into the mask’s breathing zone in order to use the patient’s breath as a fingerprint for various diseases.
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| 2. |
- Casalinuovo, Silvia, et al.
(author)
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AuNP-coated cotton as VOC sensor for disease detection from breath
- 2023
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In: Proceedings of SIE 2022. - Cham : Springer Nature Switzerland. - 9783031260667 - 9783031260650
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Conference paper (peer-reviewed)abstract
- The COVID-19 pandemic outbreak, declared in March 2020, has led to several behavioral changes in the general population, such as social distancing and mask usage among others. Furthermore, the sanitary emergency has stressed health system weaknesses in terms of disease prevention, diagnosis, and cure. Thus, smart technologies allowing for early and quick detection of diseases are called for. In this framework, the development of point-of-care devices can provide new solutions for sanitary emergencies management. This work focuses on the development of useful tools for early disease diagnosis based on nanomaterials on cotton substrates, to obtain a low-cost and easy-to-use detector of breath volatiles as disease markers. Specifically, we report encouraging experimental results concerning acetone detection through impedance measurements. Such findings can pave the way to the implementation of VOCs (Volatile Organic Compounds) sensors into smart and user friendly diagnostic devices.
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| 3. |
- Casalinuovo, Silvia, et al.
(author)
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Cotone funzionalizzato con nanoparticelle d'oro come promettente substrato flessibile ed ecologico per il rilevamento impedometrico di COV [Gold Nanoparticles-Functionalized Cotton as Promising Flexible and Green Substrate for Impedometric VOC Detection]
- 2023
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In: Materials. - : MDPI. - 1996-1944. ; 16
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Journal article (peer-reviewed)abstract
- Questo lavoro si concentra sulla possibile applicazione di nanoparticelle d'oro su tessuti di cotone flessibili come substrati sensibili all'acetone e all'etanolo mediante misurazioni di impedenza. Nello specifico, nanoparticelle d'oro (NP Au) funzionalizzate con citrato e polivinilpirrolidone (PVP) sono state sintetizzate utilizzando procedure verdi e consolidate e depositate su tessuto di cotone. Una caratterizzazione strutturale e morfologica completa è stata condotta utilizzando la spettroscopia UV-VIS e infrarossa a trasformata di Fourier (FT-IR), la microscopia a forza atomica (AFM) e la microscopia elettronica a scansione (SEM). Una caratterizzazione dielettrica dettagliata del substrato vuoto ha rivelato effetti di polarizzazione interfacciale legati sia alle NP Au che alla loro specifica funzionalizzazione superficiale. Ad esempio, rivestendo interamente il tessuto di cotone (ovvero creando una matrice più isolante), è stato riscontrato che il PVP aumenta la resistenza del campione, ovvero diminuisce l'interconnessione elettrica delle NP Au rispetto al campione funzionalizzato con citrato. Tuttavia, è stato osservato che la funzionalizzazione del citrato ha fornito una distribuzione uniforme delle NP Au, che ha ridotto la loro spaziatura e, quindi, facilitato il trasporto degli elettroni. Per quanto riguarda il rilevamento dei composti organici volatili (COV), le misurazioni della spettroscopia di impedenza elettrochimica (EIS) hanno mostrato che il legame idrogeno e la risultante impedenza di migrazione protonica sono fondamentali per distinguere l'etanolo dall'acetone.
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| 4. |
- Casalinuovo, Silvia, et al.
(author)
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Enhancing breath analysis with a novel AuNP-coated cotton sensor
- 2023
-
In: 2023 9TH INTERNATIONAL WORKSHOP ON ADVANCES IN SENSORS AND INTERFACES, IWASI. - : IEEE. - 9798350336948 - 9798350336955 ; , s. 241-245
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Conference paper (peer-reviewed)abstract
- Human health has always been a major concern for science. Over the years, health research has included different areas, ranging from specific therapies to patients lifestyle and social information: "patient-oriented" approaches have increasingly emerged as a crucial tool for health care systems, as clearly shown during the recent SARS-CoV-2 pandemic. In this context, the synergy between different scientific and technological fields, such as biology, chemistry, physics, and engineering, is increasingly considered an essential requirement. This work presents a low cost and easy-to-use sensor of volatile organic compounds (VOCs) in exhaled breath, with the purpose of serving as a rapid, non-invasive and versatile diagnostic tool in smart medicine applications. A "lockand-key" system relying on gold nanoparticles deposited on cotton fabric enables the detection of target molecules, whose adsorption produces variations in terms of electrical impedance. The system has been exposed to ethanol-based solutions in an experimental campaign to investigate the sensing capabilities at 1 Hz - 1 MHz frequency range. The results achieved demonstrate the feasibility in obtaining health-relevant VOCs detection based on impedance analysis.
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| 5. |
- Casalinuovo, Silvia, et al.
(author)
-
Gold Nanoparticles-Functionalized Cotton as Promising Flexible and Green Substrate for Impedometric VOC Detection
- 2023
-
In: Materials. - 1996-1944. ; 16:17, s. 5826-5826
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Journal article (peer-reviewed)abstract
- This work focuses on the possible application of gold nanoparticles on flexible cotton fabric as acetone- and ethanol-sensitive substrates by means of impedance measurements. Specifically, citrate- and polyvinylpyrrolidone (PVP)-functionalized gold nanoparticles (Au NPs) were synthesized using green and well-established procedures and deposited on cotton fabric. A complete structural and morphological characterization was conducted using UV–VIS and Fourier transform infrared (FT–IR) spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM). A detailed dielectric characterization of the blank substrate revealed interfacial polarization effects related to both Au NPs and their specific surface functionalization. For instance, by entirely coating the cotton fabric (i.e., by creating a more insulating matrix), PVP was found to increase the sample resistance, i.e., to decrease the electrical interconnection of Au NPs with respect to citrate functionalized sample. However, it was observed that citrate functionalization provided a uniform distribution of Au NPs, which reduced their spacing and, therefore, facilitated electron transport. Regarding the detection of volatile organic compounds (VOCs), electrochemical impedance spectroscopy (EIS) measurements showed that hydrogen bonding and the resulting proton migration impedance are instrumental in distinguishing ethanol and acetone. Such findings can pave the way for the development of VOC sensors integrated into personal protective equipment and wearable telemedicine devices. This approach may be crucial for early disease diagnosis based on nanomaterials to attain low-cost/low-end and easy-to-use detectors of breath volatiles as disease markers.
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| 6. |
- Casalinuovo, Silvia, et al.
(author)
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Measurements of Exhaled CO2 Through a Novel Telemedicine Tool
- 2023
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In: Lecture Notes in Electrical Engineering, vol 1113. Springer, Cham.. - : Springer Nature. - 9783031487101 - 9783031487118 ; , s. 396-401
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Book chapter (peer-reviewed)abstract
- This paper proposes a telemedicine tool (complete of hardware, software and 3D printed face mask) for analyzing exhaled carbon dioxide (CO2) levels. Our interest in CO2 pattern is due to its correlation to psychological and physiological health status. To achieve this information, we developed a customized printed circuit board equipped with a CO2 sensor for breath analysis, a microcontroller, a WiFi module for data transmission, and a battery for enabling an autonomous device. We also developed an interactive web page for the users and a database for daily remote data management. The device was tested on two healthy subjects of different ages and with different lifestyles. The results highlighted that the younger subject presents increased CO2 values as a direct link to a more active life. We consider these promising results for testing our device on a major cohort of observational studies.
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| 7. |
- Casalinuovo, Silvia, et al.
(author)
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Questioning Breath: A Digital Dive into CO2 Levels
- 2024
-
Conference paper (peer-reviewed)abstract
- This work presents a smart mask for real-time monitoring of carbon dioxide (CO2) levels asa reference tool for diagnosis, sports training and mental health status. A printed circuit board wasprojected and fabricated to gain data with real-time visualization and storage on a database, enablingremote monitoring as a needed skill for telemedicine purposes. The electronics were inserted in awearable device—shaped like a mask—and 3D-printed with biocompatible materials. The wholedevice was used for analyzing CO2 on a breath volunteer in three kinds of measurement.
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| 8. |
- Fraschetti, Elena, et al.
(author)
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Characterization of Disposable Facemasks for COVID-19 Through Colorimetric Analysis
- 2022
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In: NanoInnovation 2021. - : Institute of Physics (IOP).
-
Conference paper (peer-reviewed)abstract
- Many aspects of the world population's daily life have been recently changed by the events following the SARS-COV-2 pandemic outbreak. Among all the consequences, wearing face masks has become a common routine to protect from virus transmission risks. This work presents a simple colorimetric system able to detect the carbon dioxide (CO2) saturation inside a disposable face mask, which is useful to determine the level of wear and degradation and to visually provide indications on its disposal time. The experiments were carried out by wearing a FFP2 face mask externally treated with a phenolphthalein solution and including in its breathing zone a CO2 sensor. Changes in face mask color were recorded by a camera and analyzed with ImageJ. A strong correspondence was found between the high values of CO2 detected by the sensor and the analyzed data. The results are promising and suggest further efforts in developing easy-to-use colorimetric methods as a visual indicator of the life cycle of a disposable face mask.
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| 9. |
- Lai, Ian-Lin, et al.
(author)
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Gas outflow and dust transport of comet 67P/Churyumov-Gerasimenko
- 2016
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In: Monthly notices of the Royal Astronomical Society. - : OXFORD UNIV PRESS. - 0035-8711 .- 1365-2966. ; 462, s. S533-S546
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Journal article (peer-reviewed)abstract
- Because of the diurnal thermal cycle and the irregular shape of the nucleus, gas outflow of comet 67P/Churyumov-Gerasimenko could be highly anisotropic as indicated by the colliminated dust jet structures on the sunlit side. Based on the OSIRIS imaging observations of the outgassing effect, a simple model of surface sublimation can be constructed by taking into account the dependence on the solar insolation. With preliminary information on the time variability of the global gas production rate, a sequence of gas coma models can be generated at different epochs before and after perihelion. We also investigate different patterns of dust particle dynamics under the influences of nuclear rotation and gas drag. From these considerations, a consistent picture of the spatial distribution of dusty materials across the surface of comet 67P as it moves around the perihelion can be developed. It is found that because of the redeposition of the ejected dust from the Southern hemisphere to the Northern hemisphere during the southern summer season the Hapi region could gain up to 0.4 m while the Wosret region would lose up to 1.8 m of dust mantle per orbit.
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| 10. |
- Lee, Jui-Chi, et al.
(author)
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Geomorphological mapping of comet 67P/Churyumov-Gerasimenko's Southern hemisphere
- 2016
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In: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 462, s. S573-S592
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Journal article (peer-reviewed)abstract
- In 2015 May, the Southern hemisphere of comet 67P/Churyumov-Gerasimenko became visible by the OSIRIS cameras on-board the Rosetta spacecraft. The resolution was high enough to carry out a detailed analysis of the surface morphology, which is quite different from the Northern hemisphere. Previous works show that fine particle deposits are the most extensive geological unit in the Northern hemisphere. In contrast, the Southern hemisphere is dominated by outcropping consolidated terrain. In this work, we provide geomorphological maps of the Southern hemisphere with the distinction of both geological units and linear features. The geomorphological maps described in this study allow us to gain a better understanding of the processes shaping the comet nucleus and the distribution of primary structures such as fractures and strata.
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| 11. |
- Massironi, Matteo, et al.
(author)
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Two independent and primitive envelopes of the bilobate nucleus of comet 67P
- 2015
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 526:7573, s. 402-405
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Journal article (peer-reviewed)abstract
- The factors shaping cometary nuclei are still largely unknown, but could be the result of concurrent effects of evolutionary(1,2) and primordial processes(3,4). The peculiar bilobed shape of comet 67P/Churyumov-Gerasimenko may be the result of the fusion of two objects that were once separate or the result of a localized excavation by outgassing at the interface between the two lobes(5). Here we report that the comet's major lobe is enveloped by a nearly continuous set of strata, up to 650 metres thick, which are independent of an analogous stratified envelope on the minor lobe. Gravity vectors computed for the two lobes separately are closer to perpendicular to the strata than those calculated for the entire nucleus and adjacent to the neck separating the two lobes. Therefore comet 67P/Churyumov-Gerasimenko is an accreted body of two distinct objects with 'onion-like' stratification, which formed before they merged. We conclude that gentle, low-velocity collisions occurred between two fully formed kilometre-sized cometesimals in the early stages of the Solar System. The notable structural similarities between the two lobes of comet 67P/Churyumov-Gerasimenko indicate that the early-forming cometesimals experienced similar primordial stratified accretion, even though they formed independently.
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| 12. |
- Pajola, Maurizio, et al.
(author)
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Aswan site on comet 67P/Churyumov-Gerasimenko : Morphology, boulder evolution, and spectrophotometry
- 2016
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 592
-
Journal article (peer-reviewed)abstract
- Aims. We provide a detailed morphological analysis of the Aswan site on comet 67P/Churyumov-Gerasimenko (67P). We derive the size-frequency distribution of boulders >= 2 m and correlate this distribution with the gravitational slopes for the first time on a comet. We perform the spectral analysis of this region to understand if possible surface variegation is related to the different surface textures observable on the different units. Methods. We used two OSIRIS Narrow Angle Camera (NAC) image data sets acquired on September 19 and 22, 2014, with a scale of 0.5 m/px. Gravitational slopes derived from the 3D shape model of 67P were used to identify and interpret the different units of the site. By means of the high-resolution NAC data sets, boulders >= 2.0 m can be unambiguously identified and extracted using the software ArcGIS. Coregistered and photometrically corrected color cubes were used to perform the spectral analyses, and we retrieved the spectral properties of the Aswan units. Results. The high-resolution morphological map of the Aswan site (0.68 km(2)) shows that this site is characterized by four different units: fine-particle deposits located on layered terrains, gravitational accumulation deposits, taluses, and the outcropping layered terrain. Multiple lineaments are identified on the Aswan cliff, such as fractures, exposed layered outcrops, niches, and terraces. Close to the terrace margin, several arched features observed in plan view suggest that the margin progressively retreats as a result of erosion. The size-frequency of boulders >= 2 m in the entire study area has a power-law index of -3.9 +0.2/-0.3 (1499 boulders >= 2 m/km(2)), suggesting that the Aswan site is mainly dominated by gravitational events triggered by sublimation and/or thermal insolation weathering causing regressive erosion. The boulder size-frequency distribution versus gravitational slopes indicates that when higher gravitational slope terrains are considered, only boulders <= 10 m are identified, as well as steeper power-slope indices. In addition, no boulders >= 2 m are observed on slopes >= 50 degrees. This may indicate that larger blocks detached from a sublimating cliff cannot rest at these slopes and consequently fall down. The spectral analysis performed on the site shows that despite different morphologic units, no spectral differences appear in the multiple textures. This may confirm a redistribution of particles across the nucleus as a consequence of airfall, whether coming from Hapi or from the southern hemisphere when it is active during perihelion.
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| 13. |
- Pajola, Maurizio, et al.
(author)
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Size-frequency distribution of boulders >= 7 m on comet 67P/Churyumov-Gerasimenko
- 2015
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 583
-
Journal article (peer-reviewed)abstract
- Aims. We derive for the first time the size-frequency distribution of boulders on a comet, 67P/Churyumov-Gerasimenko (67P), computed from the images taken by the Rosetta/OSIRIS imaging system. We highlight the possible physical processes that lead to these boulder size distributions. Methods. We used images acquired by the OSIRIS Narrow Angle Camera, NAC. on 5 and 6 August 2014. The scale of these images (2.44-2.03 m/px) is such that boulders >= 7 m can be identified and manually extracted from the datasets with the software ArcGIS. We derived both global and localized size-frequency distributions. The three-pixel sampling detection, coupled with the favorable shadowine of the surface (observation phase angle ranging from 48 to 53), enables unequivocally detecting boulders scattered all over the illuminated side of 67P. Results. We identify 3546 boulders larger than 7 m on the imaged surface (36.4 km(2)), with a global number density of nearly 100/km(2) and a cumulative size-frequency distribution represented by a power-law with index of -3.6 +0.2/-0.3. The two lobes of 67P appear to have slightly different distributions, with an index of -3.5 +0.2/-0.3 for the main lobe (body) and -4.0 +0.31-0.2 for the small lobe (head). The steeper distribution of the small lobe might be due to a more pervasive fracturing. The difference of the distribution for the connecting region (neck) is much more significant, with an index value of -2.2 +0.2/-0.2. We propose that the boulder field located in the neck area is the result of blocks falling from the contiguous Hathor cliff. The lower slope of the size-frequency distribution we see today in the neck area might be due to the concurrent processes acting on the smallest boulders, such as i) disintegration or fragmentation and vanishing through sublimation; ii) uplifting by gas drag and consequent redistribution; and iii) burial beneath a debris blanket. We also derived the cumulative size-frequency distribution per km(2) of localized areas on 67P. By comparing the cumulative size-frequency distributions of similar geomorphological settings, we derived similar power-law index values. This suggests that despite the selected locations on different and often opposite sides of the comet, similar sublimation or activity processes, pit formation or collapses, as well as thermal stresses or fracturing events occurred on multiple areas of the comet, shaping its surface into the appearance we see today.
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| 14. |
- Pajola, Maurizio, et al.
(author)
-
The southern hemisphere of 67P/Churyumov-Gerasimenko : Analysis of the preperihelion size-frequency distribution of boulders >= 7m
- 2016
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 592
-
Journal article (peer-reviewed)abstract
- Aims. We calculate the size-frequency distribution of the boulders on the southern hemisphere of comet 67P Churyumov-Gerasimenko (67P), which was in shadow before the end of April 2015. We compare the new results with those derived from the northern hemisphere and equatorial regions of 67P, highlighting the possible physical processes that lead to these boulder size distributions. Methods. We used images acquired by the OSIRIS Narrow Angle Camera (NAC) on 2 May 2015 at a distance of 125 km from the nucleus. The scale of this dataset is 2.3 m/px; the high resolution of the images, coupled with the favorable observation phase angle of 62 degrees, provided the possibility to unambiguously identify boulders >= 7 m on the surface of 67P and to manually extract them with the software ArcGIS. We derived the size-frequency distribution of the illuminated southern hemisphere. Results. We found a power-law index of -3.6 +/- 0.2 for the boulders on the southern hemisphere with a diameter range of 7-35 m. The power-law index is equal to the one previously found on northern and equatorial regions of 67P, suggesting that similar boulder formation processes occur in both hemispheres. The power-law index is related to gravitational events triggered by sublimation and/or thermal fracturing causing regressive erosion. In addition, the presence of a larger number of boulders per km(2) in the southern hemisphere, which is a factor of 3 higher with respect to the northern hemisphere, suggests that the southernmost terrains of 67P are affected by a stronger thermal fracturing and sublimating activity, hence possibly causing larger regressive erosion and gravitational events.
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| 15. |
- Rotundi, Alessandra, et al.
(author)
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Dust measurements in the coma of comet 67P/Churyumov-Gerasimenko inbound to the Sun
- 2015
-
In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 347:6220
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Journal article (peer-reviewed)abstract
- Critical measurements for understanding accretion and the dust/gas ratio in the solar nebula, where planets were forming 4.5 billion years ago, are being obtained by the GIADA (Grain Impact Analyser and Dust Accumulator) experiment on the European Space Agency's Rosetta spacecraft orbiting comet 67P/Churyumov-Gerasimenko. Between 3.6 and 3.4 astronomical units inbound, GIADA and OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) detected 35 outflowing grains of mass 10(-10) to 10(-7) kilograms, and 48 grains of mass 10(-5) to 10(-2) kilograms, respectively. Combined with gas data from the MIRO (Microwave Instrument for the Rosetta Orbiter) and ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) instruments, we find a dust/gas mass ratio of 4 +/- 2 averaged over the sunlit nucleus surface. A cloud of larger grains also encircles the nucleus in bound orbits from the previous perihelion. The largest orbiting clumps are meter-sized, confirming the dust/gas ratio of 3 inferred at perihelion from models of dust comae and trails.
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| 16. |
- Sierks, Holger, et al.
(author)
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On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko
- 2015
-
In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 347:6220
-
Journal article (peer-reviewed)abstract
- Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck. The nucleus has a bulk density less than half that of water. Activity at a distance from the Sun of >3 astronomical units is predominantly from the neck, where jets have been seen consistently. The nucleus rotates about the principal axis of momentum. The surface morphology suggests that the removal of larger volumes of material, possibly via explosive release of subsurface pressure or via creation of overhangs by sublimation, may be a major mass loss process. The shape raises the question of whether the two lobes represent a contact binary formed 4.5 billion years ago, or a single body where a gap has evolved via mass loss.
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| 17. |
- Thomas, Nicolas, et al.
(author)
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The morphological diversity of comet 67P/Churyumov-Gerasimenko
- 2015
-
In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 347:6220
-
Journal article (peer-reviewed)abstract
- Images of comet 67P/Churyumov-Gerasimenko acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) imaging system onboard the European Space Agency's Rosetta spacecraft at scales of better than 0.8 meter per pixel show a wide variety of different structures and textures. The data show the importance of airfall, surface dust transport, mass wasting, and insolation weathering for cometary surface evolution, and they offer some support for subsurface fluidization models and mass loss through the ejection of large chunks of material.
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| 18. |
- Vincent, Jean-Baptiste, et al.
(author)
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Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse
- 2015
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 523:7558, s. 63-66
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Journal article (peer-reviewed)abstract
- Pits have been observed on many cometary nuclei mapped by spacecraft(1-4). It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments(5,6) andmodels(7,8) cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts(8,9). Alternative mechanisms like explosive activity(10) have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.
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