Compact terahertz (THz) imaging system based on narrow band microbolometer sensors (NBMS) and novel diffractive focusing optics was developed for spectroscopic microscopy applications. Frequency response characteristics of the THz antenna-coupled NBMS was found employing Fourier transform spectroscopy. As the resonant NBMS was found very sensitive room temperature (RT) THz detector, it was used to develop overall electronic system successfully applied for components analysis of packed samples via spectroscopic THz measurements. In addition, an optically thin diffractive lens with the numerical aperture of 0.62 was developed. The THz imaging system enriched with the novel lens was used for biomedical applications imaging carcinoma skin tissues with close to wavelength limited spatial resolution. The results demonstrated new potential of compact RT THz imaging systems in spectroscopic components analysis and medical diagnostic fields.
COBISS.SI-ID: 11319124
The antenna-coupled Ti-microbolometer THz sensor presented in the paper, fabricated in the standard CMOS technology using micromachining techniques. The sensitivity of this sensor is in a range of 1000 V/W at an optimal frequency and is determined by the performance of the double-dipole antenna and quarter wavelength resonant cavity. The output of the THz detector is connected to a discrete low-noise amplifier which increases the total sensitivity up to 10^6 V/W without affecting the noise equivalent power.
COBISS.SI-ID: 11886164
This paper addresses the problem of fertiliser characterisation using optical and electrical impedance methods. Comparative analysis was performed to estimate the methods effectiveness for quantitative and qualitative characterisation of water diluted fertiliser. Characterisation using optical method within the ultraviolet range indicates the variability of features that was not observed when using the impedance method. The combination of both methods showed potential for more accurate qualitative analysis than each method alone. Both methods showed good sensitivity to fertiliser concentration variation.
COBISS.SI-ID: 12227668
An inductive linear displacement measurement microsystem realized as a monolithic Application-Specific Integrated Circuit (ASIC) is presented. The system comprises integrated microtransformers as sensing elements, and analog front-end electronics for signal processing and demodulation, both jointly fabricated in a conventional commercially available four-metal 350-nm CMOS process. The microtransformers are excited by an AC signal in MHz range. The displacement information is modulated into the AC signal by a metal grating scale placed over the microsystem, employing a differential measurement principle. The microsystem design, simulations, and characterization are presented. The best results have been achieved at 4 MHz, demonstrating a linear resolution of 20 µm with steel and copper scale, having respective sensitivities of 0.71 V/mm and 0.99 V/mm.
COBISS.SI-ID: 11309396
Research, design, fabrication and results of various screen printed capacitive humidity sensors is presented in this paper. As printing ink, commercially available silver nanoparticle-based conductive ink was used. The objective of the present work was to identify the most important factors affecting the material performances with humidity, and to contribute to the development of a sensor system supported with a Radio Frequency Identification (RFID) chip directly on the material, for use in smart packaging applications. Therefore, the authors built a passive and a battery-supported wireless module based on SL900A smart sensory tag’s IC to achieve UHF-RFID functionality with data logging capability.
COBISS.SI-ID: 10694484
This article presents a color light detection system integrated in 130 nm CMOS technology. The sensors and corresponding electronics detect light in a CIE XYZ color luminosity space using on-chip integrated sensors without any additional process steps, high-resolution analog-to-digital converter, and dedicated DSP algorithm. The sensor consists of a set of laterally arranged integrated photodiodes that are partly covered by metal, where color separation between the photodiodes is achieved by lateral carrier diffusion together with wavelength-dependent absorption. The sensor system detects the color light parameters with 22-bit accuracy, consumes less than 60 µA on average at 10 readings per second, and occupies approx. 0.8 mm2 of silicon area (including three photodiodes and the analog part of the ADC). The DSP is currently implemented on FPGA.
COBISS.SI-ID: 11077972
The article offers a comparison of sensitivities for vapor trace detection of Trinitrotoluene (TNT) explosives of two different sensor systems: a chemo-mechanical sensor based on chemically modified Atomic Force Microscope (AFM) cantilevers based on Micro Electro Mechanical System (MEMS) technology with optical detection (CMO), and a miniature system based on capacitive detection of chemically functionalized planar capacitors with interdigitated electrodes with a comb-like structure with electronic detection (CE). Using CMO system, we can detect 300 molecules of TNT in 10^12 molecules of N2 carrier gas, whereas the CE system can detect 3 molecules of TNT in 10^12 molecules of carrier N2.
COBISS.SI-ID: 10678868
Double-printing of dielectric layers is commonly used to prevent electrical shorts in parallel-plate capacitors, but this increases the thickness of the dielectric layer and diminishes the corresponding capacitance. In this paper, it is demonstrated that capacitors with single-printed dielectric layers are without shorts if the layer is completely polymerized. To demonstrate this, the electrical functionality of capacitors with single-printed dielectric layers was studied in terms of intrinsic properties of the ultraviolet (UV) curable dielectric layer, which were varied according to the curing energy. The chemical structure of the cured layer was analyzed with infrared spectroscopy to obtain the appearance of polymerizable groups and crosslinks within the polymer structure.
COBISS.SI-ID: 5689370
The paper presents a novel method for fat and oedema percentage estimation in the muscle region during FSHD diagnosis. Method is proposed for the muscle-region segmentation in the T1-weighted magnetic resonance images to find the path representing the muscle-region border. The difference between the automatic segmentation and manual segmentation performed by a medical specialists is characterised using the Zijdenbos similarity index, indicating a high accuracy of the proposed method. Finally, the fat and oedema are quantified from the muscle region in the T1-weighted and T2-STIR magnetic resonance images for 10 FSHD patients.
COBISS.SI-ID: 28621351
The presented THz receiver is based on an antenna coupled titanium micro-bolometer. A new geometrical design improves the robustness and extends the lifetime of the sensor. A study of sensor lifetime using different biasing currents is presented. The lifetime was verified by several tests and over 1000 operating hours. A new micro-bolometer sensitivity measurement algorithm is presented in the paper and measurement results using the proposed algorithm are shown. The new algorithm was developed to be suitable for ATM production testing. In the paper, a novel feature called “sensitivity boosting” is described, together with its influence on sensitivity and lifetime.
COBISS.SI-ID: 12237908