Smartphone Light Research Articles

ImageJ and smartphone app chemistry analyzer using image-based colorimetric assay for quantitative detection of melamine

Abstract A smartphone-assisted microchemistry analyzer with an image-based colorimetric assay using ImageJ and a smartphone app detection method was successfully developed for the quantitative detection of melamine (MEL). The color changes of the MEL in the colloidal gold lateral flow immunoassay strip were captured and analyzed using a smartphone-controlled analyzer with an LED light source and a smartphone camera. The smartphone camera and light source were used to read the colorimetric signal from the strip, and a smartphone app was written and installed onto the smartphone. The quantitative analysis was validated with ImageJ and smartphone app colorimetric analysis. The limits of detection (LODs) for ImageJ and the smartphone app were calculated as 0.30 and 0.07 mg/L, respectively. The highly quantitative relationships between the MEL concentrations and the optical density and gray value of the ImageJ and smartphone app detection method. The designed image-based biosensor is successfully applied to detect MEL in solution of standard MEL and commercial milk samples.

Preparation of persistently luminescent polyacrylic acid-based nanocomposite ink for secure encoding

Security encoding that use photochromism has been an appealing method for fabricating efficient authentication substrates. In order to overcome counterfeiting, a unique photochromic ink was created to be utilized as a stamped film, that persistently emits light under both ultraviolet rays and darkness. Nanoparticles of lanthanide-doped aluminate (NLDA) dispersed in a polymer binder was utilized to produce a smart composite ink. In order to develop a transparent film, NLDA must be evenly distributed throughout the polyacrylic acid ink solution. Cellulosic paper sheets were stamped with the fluorescent and color-tunable nanocomposite ink. As proved by CIE (Commission Internationale de ĺEclairage) Lab parameters, a transparent appearance was achieved by stamping a homogeneous ink layer onto paper surface. Using photoluminescence spectroscopy, the stamped surfaces exhibited an absorbance peak at 365 nm and a fluorescent band at 519 nm. The stamped pattern is invisible under daylight; however, a change in color was detected from colorless to green under UV rays. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were employed to explore the structure of NLDA. Infrared spectroscopy (FTIR), energy-dispersive X-ray (EDS), scanning electron microscopy (SEM), and X-ray fluorescence (XRF) were all employed to determine the morphological features of the stamped papers. The imprinted paper sheets exhibited photochromism that could be switched back and forth between visible (colorless) and ultraviolet (green) lights without fatigue. Persistent greenish-yellow emission was detectable in the dark after exposure to smartphone light for a few seconds. Stamped sheets were analyzed for their mechanical properties, and the rheology of the photoluminescent ink was studied.

Smartphone light-driven zinc porphyrinic MOF nanosheets-based enzyme-free wearable photoelectrochemical sensor for continuous sweat vitamin C detection

Maintaining normal vitamin C levels is essential for the proper functioning of the body's immune system. The development of real-time non-invasive wearable sensors for monitoring sweat vitamin C holds important promise in guiding personalized health management. Here, we present a smartphone light-driven enzyme-free wearable photoelectrochemical (PEC) sensor based on two-dimensional zinc porphyrinic MOF nanosheets/multi-walled carbon nanotubes (2D-TCPP(Zn)/MCNTs) for the precise monitoring of sweat vitamin C. 2D-TCPP(Zn) nanosheets are prepared with the modulation of the pillared 4,4′-biphenyldicarboxylic acid (BPDC) molecules to form the final square-like structure. After the introduction of MCNTs, the developed 2D-TCPP(Zn)/MCNTs modified screen printing paper electrode exhibits an enhanced cathodic photocurrent response to vitamin C driven by smartphone light due to the effective charge separation with electron injection from 2D-TCPP(Zn) to MCNTs. A low limit of detection (LOD) of 3.61 μM and a wide detection range of 10–1100 μM for vitamin C are achieved. Also, the proposed electrode possesses high selectivity, satisfactory PEC stability and long-time storage stability. Moreover, a novel flexible PEC sensing patch was designed for the effective collection and continuous monitoring of sweat. The smartphone light-driven enzyme-free wearable PEC sensor detects the vitamin C concentration in real sweat with good accuracy, which can help to ensure proper nutritional balance.

Ultrasound-Guided In-Plane Interlaminar Lumbar Endoscopic Approach with Smartphone and Portable Light Source: Description of a New Surgical Technique

Abstract Introduction Endoscopic spine surgery enables the minimally invasive treatment of pathologies affecting the spinal cord and roots. Herein we describe an unprecedented technique Ultrasound-Guided in-plane interlaminar lumbar endoscopic approach with a smartphone and portable light source. Methods The interlaminar approach was performed in a cadaveric specimen at L4 to 5 and L5 to S1 bilaterally. A curvilinear 2 to 5 MHz ultrasound probe was employed, the puncture was performed with the needle, a guide wire was inserted until the flavum ligament, followed by the dilator and working cannula. A 30° spinal endoscope, with an optical adapter of the endoscope camera for smartphone and portable endoscope lighting was inserted, the flavum ligament was visualized, and an opening in this site was performed with the scissors. Open dissection of the specimen was subsequently performed by identifying the puncture site in the interlaminar window. Results The four interlaminar punctures were successfully guided by ultrasound; the opening of the ligamentum flavum was performed in the most lateral part of the interlaminar space, near the junction of the superior and inferior articular processes of the corresponding vertebrae in all the punctures. Discussion The ultrasound makes possible to identify facets, foramina, transverse processes, and the interlaminar space. It is possible to minimize the use of radioscopy and its associated risks, both for patients and health professionals. Conclusions The ultrasound-guided, in-plane, interlaminar, lumbar endoscopic approach with smartphone-adapted endoscope and portable light source is feasible and practical, minimizing radiation risks and making it possible to perform endoscopic spinal surgery.

Using Different Smartphone Sensors to Find the Speed of a Toy Car

There are many examples of using smartphones in physics experiments. Students and teachers can easily perform many physics experiments with the help of smartphone sensors, even experiments for which high-cost materials are needed. There are different types of such experiments in which various kinds of sensors are used. Many physical quantities can be reliably measured with smartphone sensors after some calibration. One of the physical quantities that can be determined with these sensors is object speed. For example, the angular velocities of rotating objects have been measured with a smartphone light as well as proximity, acceleration, and magnetic field sensors. The speeds of light-emitting objects traveling on a straight path and inclined plane have also been determined with a smartphone light sensor. Ball velocities have also been determined with a smartphone oscilloscope app. In this study, we determine the speed of a toy car over a certain distance using smartphone magnetic field, light, and proximity sensors simultaneously with just one experiment.

Smartphone LiDAR Technologies for Surveying and Reality Modelling in Urban Scenarios: Evaluation Methods, Performance and Challenges

The aim of the research was to evaluate the performance of smartphone depth sensors (Time of Flight Camera(ToF) and Light Detection and Ranging (LiDAR)) from Android (Huawei P30 Pro) and iOS (iPhone 12 Pro and iPAD 2021 Pro) devices in order to build a 3D point cloud. In particular, the smartphones were tested in several case studies involving the scanning of several objects: 10 building material samples, a statue, an interior room environment and the remains of a Doric column in a major archaeological site. The quality of the point clouds was evaluated through visual analysis and using three eigenfeatures: surface variation, planarity and omnivariance. Based on this approach, some issues with the point clouds generated by smartphones were highlighted, such as surface splitting, loss of planarity and inertial navigation system drift problems. In addition, it can finally be deduced that, in the absence of scanning problems, the accuracies achievable from this type of scanning are ~1–3 cm. Therefore, this research intends to describe a method of quantifying anomalies occurring in smartphone scans and, more generally, to verify the quality of the point cloud obtained with these devices.

Multifunctional 3D-printed platform integrated with a smartphone ambient light sensor for halocarbon contaminants monitoring

3D-printed platforms integrated with smartphone light sensors have become a powerful tool for the development of frugal and facile biosensing systems. Herein, we report a 3D-printed platform for multimodal analysis (3D-PMA) based on a smartphone ambient light sensor (ALS). The proposed approach was first validated using a microtiter plate reader, and then its application potential was demonstrated by measuring halohydrin dehalogenase activities employing three different sample modes, viz . using enzyme-linked immunosorbent assay (ELISA) plate strips, cuvettes, and the glass fiber membrane as sample containers. For real-sample analysis, 1,3-dichloro-2-propanol (1,3-DCP), a toxic halogenated compound, was successfully detected in spiked river water samples with recoveries in the range of 101.95–109.70%. After demonstrating the suitability for liquid-phase assays, the 3D-PMA was also optimized for 1,3-DCP detection using a glass fiber membrane. The detection could be done using a 10 μ L reaction system with an assay time of 2 min. The assay showed two linear ranges. The calibration equation of Y = 81.687x + 140.060 was obtained from the lower part of the calibration curve and was used to calculate the detection limit of the system. Under optimized conditions, a detection limit of 80 μ M was achieved for 1,3-DCP. The small size of the device endows it with great promise for use as a benchtop and an on-demand detection system. The proposed low-cost and portable system has great potential for the (bio) sensing of different biological and environmental samples where biocomponent-analyte interaction leads to a color change of the reaction system, indicating its applicability in resource-constrained settings. • A smartphone assisted portable system was developed for environmental contaminants monitoring. • 3D-printed platform demonstrated potential utility for multimodal analysis. • Smartphone Ambient Light Sensor as a potential transducer for halocarbon detection.

Quantitative experiments in a distance lab: studying blackbody radiation with a smartphone

In this paper we present an experiment aimed at investigating the thermal radiation law. The spectrum of a filament light bulb is acquired at different temperatures using a low-cost grating spectrometer based on a smartphone camera, while the measurement of filament temperature is obtained indirectly from the temperature dependence of the filament resistance. Two different methods for measuring the light intensity are tested: one is based on the use of the ambient light sensor of a smartphone, the other on a home-made grating spectrometer coupled with the smartphone camera. We observe a good agreement of the experimental data with the theoretical predictions of the Planck distribution in the limit of the Wien approximation restricted to the wavelength range characterizing the response of the smartphone light sensor and camera.

Using smartphone cameras and ambient light sensors in distance learning: the attenuation law as experimental determination of gamma correction

In times of the explosion of distance learning, because of emergency due to the pandemic, smartphone sensors and cameras are extremely valuable for teachers as they allow students to perform significant experimental activities in their own homes. The open-source software Tracker can be used in combination with the smartphone camera to perform measurements not only of mechanics activities, but also of optics. In the latter case, it is not always easy for students to understand how the pixel brightness which can be inferred from the taken photos are related to actual physical light intensity. In this paper we present a simple experiment to verify the exponential decay in the intensity of light going through successive sheets of a material (the Lambert law) with two different methods, i.e. using either the smartphone light sensor or the smartphone camera and Tracker. Besides its theoretical significance, the experiment constitutes a useful tool for calibrating the camera/Tracker combination to use it for different experiments.

A paper based colorimeter using smartphone light sensor

A paper-based colorimeter for absorbance and concentration measurement of the food colouring dye is proposed. The paper-based colorimeter system consists of a white LED as light source, paper-based cuvette holder, and smartphone light sensor. The paper-based colorimeter with smartphone light sensor is low-cost, mobile and real-time for the detection of colouring dye concentration. The detection response of the paper-based colorimeter system was found to be linear with the colouring dye concentration in the range from 0 to 0.025 g/mL with a correlation coefficient (R2) 0.89±0.04. The experimental results show that this paper-based colorimeter system is highly sensitive and have a potential application, from student labs to small industries.

Utilization of Smartphone Light Sensors as Light Transmission Analyzer During the Obtaining of Polymeric Phase Inversion Membranes

Smartphone sensors are gaining research interest due to continuous sensor upgrades, leading to more precise readings of these sensors. For this study, the light sensor of a smartphone was used in determining light transmittance during the phase inversion process of ultrafiltration polysulfone - membrane manufacturing. Membrane separation is one of the best available technologies when it comes to water and wastewater treatment. The purpose of this study was to correlate light transmit tance, at certain demixing steps during phase inversion, with membrane porosity, pure water flux and cross - sectional SEM images. Results show close relation between light transmittance and the mentioned membrane properties.

Utilising Smartphone Light Sensors to Measure Egg White Ovalbumin Concentration in Eggs Collected from Yinchuan City, China

Cost-effective, portable, and rapid smartphone sensors will play a critical role in bringing chemical detection technologies from central laboratories to simple laboratories, such as those of schools in less-developed area. In this work, we study whether eggs in Yinchuan have a higher concentration of ovalbumin than that in ordinary eggs. We summarise previous research on sensors built inside smartphones, as well as some developments in the current literature, and develop a simple experimental procedure that utilises the light sensor of a smartphone to analyse light intensity and thereby determine the ovalbumin content of egg white cheaply and quickly. Most of the materials required for conducting this experiment can be easily found in simple school laboratories, and it allows solution concentrations to be quickly assessed by high school students in the data collection and analysis phase. Indeed, the data collected using smartphone light sensors were similar to those obtained using a spectrometer. It was concluded that egg white ovalbumin concentration in eggs collected from Yinchuan is higher than that in ordinary eggs.

Patients' perception of using a smartphone light source in the clinical environment.

Introduction A satisfactory light source is of paramount importance during an oral head and neck examination. It has become common practice for the light source on a smartphone to be used during inpatient intra-oral examination. We determined if patients identified the use of a smartphone as a light source, during head and neck examinations, as unprofessional.Methods and materials A clinical photograph illustrating professional errors was presented to patients as a pilot survey (n = 10); a smartphone camera flash being used as a light source was featured. Patients were then asked which aspects they considered unprofessional. Following staff training and improvements to the survey wording, the same photo was presented to patients (n = 150) as the main study.Results Of the patients surveyed, 97% considered the use of a smartphone in the staged clinical photograph as unprofessional. They also noted: a clinician sitting on the bed (88%), clinicians not wearing gloves (81%), lack of privacy/curtain not drawn (62%), long hair not tied back (50%), a clinician's name badge not visible (23%), clinician bare below the elbows (15%) and clinician not wearing a tie (12%).Conclusions This is the first piece of research into the use of a smartphone light source within clinical examination. The use of a smart phone light source during clinical examination was the most reported 'error' and was recognised more than a clinician not wearing gloves. Eighty-five percent of patients considered the use of a smartphone light source unprofessional. Authors, therefore, do not advocate the use of a smartphone light source in the clinical care of patients.

Light Intensity Analysis Using Smartphone’s Light Sensor

Light is a form of electromagnetic energy radiation emitted in the visible part of the spectrum. This study was aimed to analyze the intensity of dynamic train light that moves constantly on a linear track using a smartphone light sensor. The method used in this research was the experimental method. The light sensor application used is available freely in the Physics Toolbox Suite on the smartphone. Experimental equipment was built using linear tracks, dynamic trains, flash light and lamp. Light sensor output produces luminosity (Ev) value versus time (s). The experimental results show that the light intensity at 3 volts with a distance of 5, 10, and 15 cm are 100, 250 and 300 cd, respectively. Whereas the intensity of light at 4.5 volts, the intensity of the light at distances of 5, 10, and 20 cm are 800 cd, 950 cd and 1200 cd, respectively. It is expected that the use of smartphones can increase students’ interest in learning physics concepts.

Effect of Smartphone Light Fluxes on Cornea: A Biophysical Study.

Objective:Biophysical study to investigate (a) the effects of smartphone light fluxes (SPLF) on isolated mammalian cornea and model protein (insulin), (b) to predict the possible visual interference of SPLF.Materials and Methods:Fresh goat cornea and insulin protein were used as an experimental model system. The energy of absorbed SPLF was measured using chemical dosimeter. The effect of SPLF on the aggregation of model protein was studied using fluorescence spectroscopy and dynamic light scattering (DLS). Fluorescence microscopy, scanning electron microscopy (SEM), DLS, were used for cornea imaging.Results:The spectral emission peak of SPLF was observed at 380 nm and 420 nm. Absorbed radiation of SPLF was found to be 2.82 mWm-2 and 1.92 mWm-2 for collimated (focussed) and noncollimated (nonfocussed) condition, respectively. Secondary structural changes of insulin were observed by fluorescence and zeta potential after SPLF exposure. SEM study revealed the disorganization of the epithelial cell surface, increase in intercellular space, disorganization of primary epithelium layer, and exposure of the second layer is seen in depth. Differential Interference Microscopy showed an optical gradient in images that appears to be changed in specimen structure. Fluorescence microscopy showed disorganization in epithelial cell pattern. A significant difference in bio-molecular permeation was observed in the exposed cornea. Ultraviolet UV-visible spectroscopy study indicated a reduction in light transmission through the cornea.Conclusions:The obtained results indicate changes in physicochemical and morphological modifications in the cornea and insulin modifications after exposed to SPLF.

Patients consider a smart phone light source as unprofessional as not wearing gloves during OMFS examinations

Patients consider a smart phone light source as unprofessional as not wearing gloves during OMFS examinations

Indoor Localization Using Smartphone Magnetic and Light Sensors: a Deep LSTM Approach

With the increasing demand for location-based services, indoor localization has attracted great interest. In this paper, we present DeepML, a deep long short-term memory (LSTM) based system for indoor localization using magnetic and light sensors on smartphones. We experimentally verify the feasibility of using bimodal data from magnetic and light sensors for indoor localization for closed environments where there is no ambient light. We then design the DeepML system, which first builds bimodal images by data preprocessing, and then trains a deep LSTM network in the offline phase. Newly received magnetic field and light data are then exploited for estimating the location of the mobile device using a probabilistic method. The extensive experiments verify the effectiveness of the proposed DeepML system.

The effect of smartphone light on the physiology signal and cognitive function in circadian environment

Many people are constantly exposed to artificial light caused by digital devices such as computer, smartphone, and TV. Prolonged exposure to artificial light disturbs our circadian rhythm, cognitive function and autonomic nervous system (ANS). Therefore, this study aimed to analyze the alterations in physiological signals and cognitive functions following exposure to smartphone light in order to confirm the effects of artificial light on the human body. Normal adults aged from 21 to 28 were engaged in this study. The experiments were conducted in day (10:00~14:00) and night (8:00~12:00) conditions. Experimental subjects were divided into three groups according to smartphone screen brightness; 50%, 100%, and blue light filter (BLF), then used smartphone for 10 min/set (rest time: 5 min) and repeated the task three times. The ANS changes were confirmed using pulse pressure measurement equipment. Short‐term memory (STM), long‐term memory (LTM), and recognition tests were conducted via language memory test (LMT) and visual memory test (VMT). After using smartphone at daytime condition, 50% group shoed significantly increased ANS activity. Also, LTM and recognition were significantly increased in the 50% and BLP group. In night condition, however, BLF group showed increased LTM and recognition. It has been demonstrated by this study that smartphone light may influence ANS, memory, and cognitive functions. Accordingly, blue light filter is recommended when using smartphone to reduce such harmful alterations.Support or Funding InformationFunds: NRF‐2017R1A2A2A01067169, KGM4611821, 2016 Creative Research Program of Inje University, Republic of KoreaThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

스마트폰 조명에 의한 망막내의 Lipofuscin인 A2E의 광산화 효과와 청색광 차단 렌즈에 의한 광산화 방지효과

스마트폰 조명에 의한 망막내의 Lipofuscin인 A2E의 광산화 효과와 청색광 차단 렌즈에 의한 광산화 방지효과

A simple pendulum-based measurement of g with a smartphone light sensor

A quick and very accessible method for the measurement of acceleration due to gravity is presented. The experimental set-up employs a smartphone ambient light sensor as the motion timer for measuring the period of a simple pendulum. This allowed us to obtain an experimental value, 9.72 + 0.05 m s−2, for the gravitational acceleration which is in good agreement with the local theoretical value of 9.78 m s−2.