Metal shape detection and evaluation using giant magneto resistance system

Visual inspection to locate metals embedded in walls or floors is impractical. Detection of these metals can only be done with a proper metal detection. Accordingly, the development of a magnetic imaging system based on giant magneto-resistance (GMR) sensors is presented for metal shape detection. This system is based on magnetic flux leakage testing (MFLT) principle for detecting the shape of ferromagnetic material specimens. The imaging system is constructed using 21 linear GMR sensors array as signals sensing unit (SSU). In this study, a few ferromagnetic SS400 mild steels specimens in various shapes are used as specimens. Image produced confirm system functionality in detecting and evaluating metal shapes

Design and simulation of one-port SAW resonator for wireless and high temperature application

This paper present the full design consideration, operational principle, structure and frequency response simulation of one-port Surface Acoustic Wave (SAW) Resonator using Micro Wave Office (MWO) and MATLAB used for passive wireless sensing of various measurands. Since SAW Resonators are widely used in radio frequency sensing application, the development and evolution of present day SAW devices has been possible only due to simultaneous efforts to simulate these devices and also it is desirable to evaluate the device prior to fabrication especially in cases where the characteristic of device material and dimensions have a major influence on the performance of the overall system. The equivalent circuit model approach has been used to simulate the frequency response of one-port SAW resonator base on gallium orthophosphate (GaPO4) with 5deg cut-angle at 433.92 MHz under ISM band frequency for high temperature wireless application and it appears that this modeling is suitable for near resonance frequency, also measuring dielectric permittivity of GaPO4 at this frequency for use of modeling

CO2 gas sensing properties of screen printed La2O3/SnO2 thick film

The present investigation deals with the fabrication of CO2 gas sensor based on La2O3/SnO2 metal-oxide material. In this paper, the sensitive material was prepared by La2O3/SnO2 nanopowder and the addition of 1 wt. % and 3 wt. % platinum (Pt) using high-speed ball milling method. The sensitive film prepared by sensitive powder was printed on alumina (Al2O3) substrate by screen printing method. This film was characterized by X-Ray powder diffraction spectroscopy, and Field-emission scanning electron microscopy. As a result, the prepared 3 wt. % Pt/La2O3/SnO2 thick film sensitive paste exhibits a high sensitivity to increasing the CO2 gas concentration at 225 °C in air atmosphere

Design and development of Ni0.75Zn0.25Fe2O4/MWCNT microstrip patch antenna (MPA) for ISM band spectrum applications

This research paper represents the design and development of a microstrip patch antenna (MPA) for the ISM (Industrial, Scientific and Medical) band spectrum applications. The main objective of this paper is to analyze the performance of the MPA design using new engineering materials (Ni0.75Zn0.25Fe2O4/MWCNT) synthesized through chemical vapour deposition (CVD) method by utilizing the use of waste cooking oil (WCO) as a carbon source which acts as a printed radiating patch in order to replace a copper or gold (conventional) radiating patch in previous literature. The proposed antenna is fabricated on kapton substrate with dielectric constant, εr = 3.4 and loss tangent, tan δ = 0.004. The conducting patch is Ni0.75Zn0.25Fe2O4/MWCNT and ground antenna material is copper. The results demonstrate that the antenna is capable to comprehend return loss (RL) of – 24.03 dB at frequency of 2.43 GHz with bandwidth of 1.00 GHz and voltage standing wave ratio (VSWR) of 1.14. The antenna has overall dimensions of 33.60 × 41.74 × 0.025 mm3

Three-dimensional finite element analysis of GaPO4/Pt surface acoustic wave resonator based on cell model.

This paper present a three-dimensional finite element method for the one-port surface acoustic wave resonator base on GaPO4 with 5° cut for high frequency application. Interdigital transducer is assumed a thin film platinum with chromium as an under-layer material. The simulated frequency response and wave propagation are obtained under base cell model at 433.92 MHz centre frequency under ISM band. Frequency responses versus impedance are compared and verify with the known result in literature. The results show that the total displacements are vanished at a distance of about 2 to 3 wavelength from the surface. As expected, the X and Y displacement are 90°out-of-phase with each other. It is observed that the mass loading effect is suitable for prediction of resonant frequency. It is Q found that the factor value is larger than 1000 and the mode shapes for resonant and anti-resonant condition are different at two edges of stop-ban

Synthesis of ZnO nanorods by microwave-assisted chemical-bath deposition for highly sensitive self-powered UV detection application

High-quality vertically aligned zinc oxide (ZnO) nanorods were successfully grown on seeded silicon substrates p-Si(100) through microwave-assisted chemical bath deposition. Structural and morphological analyses revealed hexagonal wurtzite nanorods perpendicular to the substrate along the c-axis in the direction of the (002) plane. Optical measurements showed a high-intensity UV peak with a low broad visible peak. UV emission was compared with the visible emission having an IUV/Ivis ratio of 53. A metal–semiconductor–metal-based UV detector was then fabricated by depositing two metal contacts onto the ZnO nanorod surfaces. Current–voltage measurements revealed a highly sensitive device with a self-powered characteristic. At zero applied bias, the fabricated device showed a significant difference between the UV current and dark current. The device further showed a sensitivity of 304 × 104 to low-power (1.5 mW/cm2) 365 nm light pulses without an external bias. Photoresponse measurements demonstrated the highly reproducible characteristics of the fabricated UV detector with rapid response and baseline recovery times of 10 ms. This work introduced a simple, low-cost method of fabricating rapid-response, highly photosensitive UV detectors with zero power consumption

An Experiment of Thick Film Force Sensor Using MEMS Simulation Software.

Force sensor (or pressure sensor) has gained increasing interest among the researchers. Using the Microelectromechanical Systems or MEMS technology, the size of the force sensor can be miniaturized and this ignites more possible application in the field of biomedical and robotic applications. Recent researches show the application of force sensor on the prosthetic hand, an artificial limb connected to an amputated person. This paper presents on simulating the sensitivity of the thick film force sensor using IntelliSuite software. The force sensor is realized by using the piezoresistive material on the cantilever structure. There are three force sensor designs are simulated. Two of the designs are simulated using glass as substrate, and while the remaining one is of alumina substrate. The sensitivity simulated is much smaller compared to the estimations made using equations. The simulations show that the glass sensor fares better than the alumina sensor. If the substrate is the same, the sensor with the bigger dimension has better sensitivity