This article contains information about electromagnetic field that is emitted by mobile devices and their impact on human body. Another matter discussed in this article are the legal aspects of phones radiation and determination of absorption rate, SAR measurement standards and the correlation between smartphones upgrades and their radio performance. The main aim, of developing the technology of a device generating an electromagnetic field, with similar value to smartphone is to simulate feasible it, during the study of the vital functions of living cells and the impact of electromagnetic on them.
This work represents an effective method for synthesis and doping of ZnSe nanocrystals with elements of group 3 and transition elements. The structure of crystals and their average size are determined. The spectra of optical density and photoluminescence were studied, and a comparative analysis of characteristics of the obtained nanoparticles with their bulk analogs was carried out.
This paper includes informations about electromagnetic fields generated by mobile phones and their possible impact on humans health. The second point is definition of Specific Absoption Rate and law regulations connected with allowed values of phones radiation. Both SAR measure standards have been described. There is also the relationship between mobile phones development and their radio performance. The main aim is the project and simulation of device generating the electromagnetic field, which values are approximative to fields generated by mobile phones in order to measure the vital functions of cultured cells.
The given data on the optical arrangement, in which the coordinate distributions of the real and imaginary component of the elements of the Jones matrix of optically thin polycrystalline layers are determined. Algorithms are presented and an experimental method for measuring the real and imaginary component of Jones-matrix images is analyzed. The experimental results of the study of statistical, correlation, and fractal parameters, which characterize the real component of the Jones-matrix image of polycrystalline networks of flat layers of the main types of human amino acids, are presented.
This article researches the proposed physical and mathematical model of a digital coherent optical spectrum analyzer, the spatial spectral bandwidth of which is limited by the diffraction of light on the matrix structure of the modulator. To expand the bandwidth of the spectrum analyzer, proposed to illuminate the modulator with a plane wave that incident on the modulator at a certain angle, similarly to the Leit-Upatnieks hologram. The research of the model has shown that when the modulator is illuminated with an inclined plane wave, the form of the diffraction pattern does not change, but the whole picture is shifted. To expand the operating spectral range (bandwidth), it is necessary that two diffraction maximum of the 0-th and + 1st orders incident into the entrance pupil of a Fourier lens, and when they are recorded, the entire sensitive surface of the matrix radiation detector is fully used. In this case, the operating range of the spectrum analyzer is equal to twice the Nyquist frequency of the modulator.
This communication has been dedicated to spectral properties of system composing of periodic arrays of layers which form superlattice with electron effective mass dependent on coordinate inside of each layer. We considered one dimensional model which admits to obtain the exact solution of wave equation. The position dependent mass inside the layer was represented by the linear function. We has found wave functions in their explicit and exact forms as well as the secular equation for the energy eiguen values. The energy spectrum of electrons as expected manifests properties typical for periodic nanostructures.
The influence of metabolic, molecular genetic- and immune-inflammatory factors on the course of reparative osteogenesis and the formation of bone nonunion of long bones is investigated on the basis of computer statistical analysis and forecasting methods. It has been established that hyperhomocysteinemia, dyslipidemia and cytokine imbalance are negative regressors of the structural and functional state of bone tissue, leading to increased levels of bone resorption markers and the development of systemic and local osteoporosis. The genetic determinants of the course of reparative osteogenesis in a hypoplastic and atrophic type are the homozygous carrier of mutations MTHFR C677T or eNOS T786S, as well as a combination of both polymorphisms.
In this paper the construction and technology of the dual-band UV-VIS photodetector has been shown. The designed and manufactured device allows for parallel monitoring of a single signal path in two different optical bands. The presented device consists of two independent photodiodes, the first of them is developed silicon carbide diode working in UV range, and the other one can be any VIS photodiode available commercially.
This paper is related with matters of mapping in robotics also known as SLAM which expanision means Simultaneous Localization and Mapping. The first point includes making a project of mechanical construction, match of sensors necessary to create a map and making a choice of Arduino board. The second part was creating the real model of robot and making electrical connections between modules. As the one before last target, programmes have been written. They are dedicated to create a room map. The final purpose was creating of small area map.
TiO2 thin films were deposited on glass substrates by HiTUS (high target utilization sputtering) technique.
Structural studies of TiO2 thin films of different thickness were performed by X-ray diffraction. Refractive index and
extinction coefficient were measured by spectroscopic ellipsometer. Transmission spectra of TiO2 thin films were
investigated in the temperature interval 77-300 K. The temperature behaviour of Urbach absorption edge for TiO2 thin
film was studied. The effect of temperature on the optical parameters and order-disorder processes in TiO2 thin films was
analysed.
Pulse laser deposition technique was used to deposite (Ag3AsS3)0.6(As2S3)0.4 thin films upon previously prepared gold nanoparticle layers. The optical transmission spectra of sandwich structure based on Ag3AsS3)0.6(As2S3)0.4 thin film and gold nanoparticles were studied in the temperature range 77-300 K. Temperature behaviour of the Urbach absorption edge as well as the temperature dependences of the energy pseudogap and Urbach energy were investigated. The effect of the order-disorder processes on the optical properties of sandwich structure was discussed. Optical parameters of Ag3AsS3)0.6(As2S3)0.4 thin film and sandwich structure based on (Ag3AsS3)0.6(As2S3)0.4 thin film and gold nanoparticles were compared.
In the article the physical mechanism of optical radiation co-operation with semiconductor devices, technological route of making of MOS - phototransistor with bilateral illumination of channel has been considered. Also the optical transducer with frequency output based on the structure of the bipolar-field transistors with negative resistance and MOSFET with bilateral illumination of channel that is a photosensitive element has been considered. A mathematical model of the radio measuring optical transducer has been developed.
This paper presents issues related to the creation of research plates with titanium electrodes, which are a new alternative to currently used plates with gold electrodes. Methods for obtaining metallization of titanium, necessary for the production of electrodes are described. Various lithography techniques are presented for processing the obtained layer of the material. The stages of designing and manufacturing comb capacitors and ready-made research plates have been presented. Finally, substrates with a titanium layer have been designed and manufactured to allow the impedance of living cells to be measured.
The article presents the construction and technology of comb capacitors on a polycarbonate substrates. The structures have been designed to be used in the ECIS measurement system that allows monitoring the activity of the examined cells by analyzing the changing electrical parameters impedance, resistance and capacitance in real time. The copper layer was embedded by sputtering method. The resulting comb capacitors were used in a test sample of substances with different chemical properties.
This paper presents the design and simulation of four different structures of nichrome microheater on the polycarbonate substrate. Nichrome layer is covered by the silicon nitride dielectric layer. The comb capacitor covering dielectric layer is used for measuring electrical parameters of liquids. Designed structure allows impedance, resistance and capacitance monitoring of studied substances like chemical or biological liquids, which require constant heating value on the substrate surface. 3D model design and electro-thermal finite elements simulations were carried out by CoventorWare software. Various shapes of the heaters were studied to check the uniformity heating on the active surface.
This paper describes the technology and characterization of HgCdTe photodetectors developed in Vigo System S.A.. Four different variations of devices have been made which include different substrate types and different passivation coatings. CdTe passivation and anodization have been compared. Additionally, both passivations have been strengthened using a negative photoresist SU-8. As fabricated devices have been destined to work as infrared radiation detectors, there has been performed a current measurement for reverse polarization. Based on current-voltage characteristics, current densities have been calculated and compared among fabricated photodiodes to find the best solution of examined passivations.
To this day, the micro-heating unit in a multiparametric capillary sensor’s setup has been controlled using laboratory power supply with constant voltage. In this method it was assumed that the micro heater’s resistance value is semi-constant. However, due to the fact that degradation effects induced by high power density dissipation in multiple, intense or prolonged heating cycles may cause it to vary, a new approach had to be found. Therefore, in this paper, a development of a power stabilization method using PID controller to compensate for micro-heater’s resistance changes during intense heating is described. Additionally, a current sensing resistor, a programmable power supply and a data acquisition system are incorporated into the setup to provide closed-loop feedback.
This paper presents the technological issue of silicon carbide MOSFET design. Through the use of simulations of silicon carbide transistor, the influence of the different the technological parameters are described and discussed. MOSFET transistor was performed in Silvaco TCAD using technology elaborated at Lublin University of Technology. The most important parameters related to ion implantation, which was used in p-i-n photodiode technology. The electrical simulations were performed, transfer and output characteristics for different values of technological parameters were generated – influence of gate oxide thickness on threshold voltage and influence of channel length modulation were checked. The results of simulations as well as transfer and output characteristics allowed to select optimal parameters between expected device working and available technology – gate oxide thickness and transistor channel length were established. This work was in fact carried out to increase our understanding of the device characteristics so as to allow the design of new SiC circuits which could meet the stressful requirements of ultraviolet detector systems.
The rapidly growing demand for electronic devices requires using of alternative semiconductor materials, which could replace conventional silicon. Silicon carbide has been proposed for these harsh environment applications (high temperature, high voltage, high power conditions) because of its wide bandgap, its high temperature operation ability, its excellent thermal and chemical stability, and its high breakdown electric field strength. The Schottky barrier diode (SBD) is known as one of the best refined SiC devices. This paper presents prepared model, simulations and description of technology of 4H-SiC Schottky junction as well as characterization of fabricated structures. The future aim of the application of the structures is an optical detection of an ultraviolet radiation. The model section contains a comparison of two different solutions of SBD’s construction. Simulations – as a crucial process of designing electronic devices – have been performed using the ATLAS device of Silvaco TCAD software. As a final result the paper shows I-V characteristics of fabricated diodes.
Today, methane sensors find applications mostly in safety alarm installations, gas parameters detection and air pollution classification. Such sensors and sensors elements exists for industry and home use. Under development area of methane sensors application is dedicated to ground gases monitoring. Proper monitoring of soil gases requires reliable and maintenance-free semi-constant and longtime examination at relatively low cost of equipment. The sensors for soil monitoring have to work on soil probe. Therefore, sensor is exposed to environment conditions, as a wide range of temperatures and a full scale of humidity changes, as well as rain, snow and wind, that are not specified for classical methane sensors. Development of such sensor is presented in this paper. The presented sensor construction consists of five commercial non dispersive infra-red (NDIR) methane sensing units, a set of temperature and humidity sensing units, a gas chamber equipped with a micro-fan, automated gas valves and also a microcontroller that controls the measuring procedure. The electronics part of sensor was installed into customized 3D printed housing equipped with self-developed gas valves. The main development of proposed sensor is on the side of experimental evaluation of construction reliability and results of data processing included safety procedures and function for hardware error correction. Redundant methane sensor units are used providing measurement error correction as well as improved measurement accuracy. The humidity and temperature sensors are used for internal compensation of methane measurements as well as for cutting-off the sensor from the environment when the conditions exceed allowable parameters. Results obtained during environment sensing prove that the gas concentration readings are not sensitive to gas chamber vertical or horizontal position. It is important as vertical sensor installation on soil probe is simpler that horizontal one. Data acquired during six month of environment monitoring prove that error correction of methane sensing units was essential for maintenance free sensor operation, despite used safety procedures.
KEYWORDS: Sensors, Actuators, Microfluidics, Capillaries, Resistance, Control systems, Silicon, Thin films, Temperature metrology, Control systems design
MEMS actuators are currently widely used in the industry. Micro-heaters, being a prime example, attracted much attention in recent years due to their good operating parameters and low cost fabrication process. This paper focuses on a design and development of a micro-heater to be used as an actuator in a multiparametric capillary sensor. The micro-heater is an evolution of a previous design and uses a 200nm-thick thin film of 80/20 NiCr alloy as a heating layer. The paper presents results of fabrication and testing of the micro-heater, including temperature distribution and resistance changes during the heating cycle. Additionally, is presented a PWM based control system providing the stability of power and temperature distribution.
This paper presents analysis of mechanical strength and reliability of wire bonds in context of the applied bonding technique, wire material and substrate type used as well as bonding parameters. The investigation conducted includes a selection of parameters affecting process of effective wire bonds forming by 53XX F&K Delvotec Bonder and implementation of wire bonds with ultrasonic and thermosonic techniques, using various substrates combined with gold and aluminum 25 μm diameter wires. Furthermore, reliability and quality test made by bond pull technique have been presented and discussed.
Local liquid sample heating is used in multiparametric sensors of liquid type classification and in sensors of liquid flow. In such applications, the heating of the liquid is done by micro-heaters, with the liquid separated from the micro-heater. The presented paper concentrates on the physical conditions of liquid sample heating used in capillary sensors. In such devices the repeatable transfer of heat is required. The basic measurements include time of liquid to vapor phase transitions and local transfer of heat. In the work were used experimental and simulation techniques. The obtained results show that in the capillary sensor repeatable local heat transfer conditions can be easier achieved than repeatable time of liquid to vapor phase transitions. In the analyzed case, the local heating depends mostly on the capillary to micro-heater distance. The liquid to vapor transition times, beside of the liquid type, depend on the powers used for micro-heater heating and on capillary cross-section parameters, such as the inner and outer diameter values. By increasing the power to the micro-heater the transition time variability is reduced.
Technology, characterization and in particularly modeling of 4H-SiC photodiode have been presented in this paper. Modeling and simulation has been performed using PSPICE environment. Comparison of simulation with real results for electrical characteristic (I-V) of circular SiC photodiodes has been also presented.
The time series sequence of data readings are the input for computer aided analysis of signal from the multiparametric
optical capillary sensor. The time series signals have characteristic points and forms. Their analysis by trained human
operators is time consuming and sometimes lacks of precision because of the presence of signal noise. The noises can be
mostly rejected with advanced electronic signal processing, but the output analog signal is often modified by the
electromagnetic environment and by the noise generated by electronic elements. We propose and analyze an algorithm
that can be used as an automatic detector of characteristic points and form of the time series signals that are produced by
the measuring head and the analog electronic units of the biodiesel fuel quality test sensor.
The local heating enables liquid classification in multiparametric capillary sensors. The dispersion of capillary and microheater parameters may determine the sensor action. Therefore, this paper focuses on the analysis of a local heating implemented in mentioned sensor. The microheater consist of 4H-SiC volume heating unit, alundum ceramic base and a glass capillary is modeled and simulated using CoventorWare™. We use finite element method (FEM) to determine thermo-mechanical parameters of the designed structure. Obtained results are then compared and verified with experimental research. The influences of a capillary to microheater distance and capillary’s thickness on the output results are examined.
This paper provides an overview of the process of 4H-SiC pn junction fabrication and characterization. The samples used in this study were fabricated in a resistively heated horizontal hot-wall Chemical Vapor Deposition reactor. The homo-epitaxial layers were grown on commercially available 4H-SiC substrates (Cree). In order to obtain p-type epilayers, they were intentionally doped with aluminum. In this work, we present our recently developed 4H-SiC pn junctions fabrication and characterization results. The ohmic contacts were formed using evaporation, etching, lift-off and high temperature annealing. Current-voltage characteristics of the devices were demonstrated.
Silicon Carbide (SiC) photodiodes have been proposed in recent years for ultraviolet (UV) light detection because of their robustness even in harsh environments, high quantum efficiency in all the UV range (200nm-400nm), excellent visible and infra-red blindness excluding UV filters implementation, low dark current and high speed. 4H-SiC has a bandgap three times larger (3.26eV) than Si and, thus, SiC detectors should have much higher sensitivity than Si detectors. In this paper, we present an overview of results on 4H-SiC p-i-n junctions fabrication and characterization. We used implantation technique to obtain p-region of the investigated structure. The ohmic contacts were formed using evaporation, etching and lift-off. Current-voltage, contact resistance and electroluminescence are the main characteristics of the presented devices. All the diodes showed excellent rectification with leakage current density of less than 10-9A/cm2.
This paper describes the construction, fabrication and properties of large-area ultra violet detector that is transparent in the visible range. The device was made on n-type 4H SiC substrate with a double epitaxial layer in which aluminum was implanted to form a p-n junction close to the surface, and a SiO2 layer was formed for passivation, without a guard ring. The design of the top and bottom electrodes of 4mm diameter UV sensitive area allows not less than 20% visible range transmission. This transmission was measured across sensitive area of examined devices and was only 5% lower than that of the substrate before implantation and electrodes deposition.
This paper focuses on the design and analysis of a MEMS piezoresistive pressure sensor. The absolute pressure sensor with a 150μm wide and 3μm thick silicon membrane is modeled and simulated using CoventorWare™ softwareprofiting from a finite element method (FEM) implemented to determine specific electro-mechanical parameter values characterizing MEMS structure being designed. Optimization of piezoresistor parameters has been also performed to determine optimum dimensions of piezoresistors and their location referred to the center on the pressure sensor diaphragm. The output voltage measured on a piezoresistive Wheatstone bridge has been obtained and compared for two different resistor materials along with and linearity error analysis.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.