N.M.A.M. Institute of Technology

Undoped and magnesium-doped MnS thin films (with 1, 3, 5, and 10 wt% Mg) were synthesized on glass substrates using the spray pyrolysis technique. Structural, optical, and electrical properties of the films were studied. Powder x-ray diffraction (XRD) analysis revealed that the undoped MnS and Mg-doped MnS thin films (1%, 3%, and 5% Mg) exhibited an amorphous structure. However, when the Mg doping concentration increased to 10%, the XRD pattern showed slightly improved crystallinity, with the emergence of peaks corresponding to the hexagonal wurtzite structure (gamma-MnS). The composition of the thin-film material was analyzed using the EDS technique, which revealed the formation of a thin-film composite. In the UV-vis absorption spectra, all the MnS and Mg-doped MnS thin film composites exhibited maximum absorption around 365 nm in the ultraviolet region, with absorption gradually decreasing across the visible region (400-800 nm). The thickness and the morphology of the thin film composite were measured using the SEM technique. High-resolution transmission electron microscopy (HRTEM) was used to study the crystallinity of the thin films. Photoluminescence (PL) was used to analyze light emission under excitation. The oxidation states of the films were analyzed by x-ray photoelectron spectroscopy (XPS). Electrical characteristics were evaluated through Van der Pauw Hall effect measurements.

This paper presents the design, modeling, and simulation of a double differential microelectromechanical system (MEMS) sub-micronewton ( N) force sensor integrated with a Pentacene Thin-Film Transistor (PTFT) readout circuit. The proposed sensor offers low-cost fabrication, low-voltage operation, high sensitivity, and effective cross-axis signal rejection. The sensing structure comprises a central silicon proof mass supported by four beams, each embedded with indium tin oxide (ITO) piezoresistors positioned at regions of maximum tensile and compressive stress. The PTFT was modeled and simulated using TCAD and implemented in Cadence Virtuoso through a Verilog-A model. Differential outputs are processed through a negative-feedback operational amplifier with a gain of 20. An identical setup is implemented on an adjacent flexure of the MEMS structure, and both outputs are compared using a differential comparator. A non-zero comparator output indicates a sensing error. Finite element simulations in COMSOL Multiphysics indicate a nominal resistance ( Δ R/R ) variation of 0.095, with the PTFT operating at – 3 V (threshold voltage – 1.2 V). The sensor achieves an output change of 10 mV, corresponding to a sensitivity of 10 V/nN. The proposed double differential architecture, combined with a PTFT-based readout circuit, ensures accurate nano-force sensing with immunity to cross-axis interference, which further enhances the capability of future MEMS force sensors.

In the present study, titanium dioxide nanoparticles (TiO2NPs) are synthesized via the combustion method using titanium (III) sulfate and urea as oxidizer and fuel at 750 degrees C and confirmed through morphological and structural analysis. The electrode modification is performed by arginine modification with titanium oxide on the surface of the CPE in noradrenaline determination using the linear sweep voltammetric (LSV) technique. Voltammetric analysis was performed in 0.1 M PBS of pH 6.7 at a scan rate of 0.1 Vs-1. The pH studies indicated the deprotonation reveals the electrochemical oxidation by a diffusion-controlled process, with a recorded detection limit (LOD) of 0.03 mu M. These results suggest that the proposed approach offers high sensitivity, repeatability, reproducibility, selectivity, and stability, making it suitable for determining NA content in clinical and pharmaceutical samples.

In this work, titanium dioxide (TiO2) nanoparticles (NPs) are prepared by a facile combustion method and is confirmed through various characterization techniques such as X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive x-ray spectroscopy (EDS) and Raman analysis. The serine-modified titanium dioxide carbon paste electrode (SM/TiO₂/CPE) is fabricated using synthesized nanoparticles and electropolymerized serine (S), and employed as an electrochemical sensor for the determination of rutin via various voltammetric techniques. It was found that the high sensitivity and selectivity of the SM/TiO2/CPE material is fabricated to achieve the enhancement in electrochemical study. The pH reveals that 6.7 found to be suitable for the detection of H+ ions. The electro-oxidation and reduction of rutin is reversible and controlled by the diffusion process through scan rate. The electrochemical impedance study (EIS), cyclic voltammetry (CV), linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV) techniques were used to find the detection limit (LOD) with range of 0.01 µM to 0.25 µM for CV, 0.01 µM to 0.25 µM for LSV, and 0.01 µM to 0.21 µM for DPV and the obtained were 0.04 for CV, 0.01 for DPV, and 0.05 for LSV, which is smaller than the previously reported data. The proposed approach aims to ensure quality assurance while enabling the effective determination of rutin in tomato juice sample. TiO2 NPs were synthesized by facile combustion process. TiO2 NPs was used for electrochemical detection of rutin in tomato sample. Electro-oxidation and reduction include two electrons and protons with diffusion-controlled process. Highest sensitivity with a detection limit of 0.04 for CV, 0.01 for DPV, and 0.05 for LSV of rutin. Prototype developed and utilized for the determination of rutin in tomato sample.

Herein, we focus on optimising the electrospinning parameters to fabricate well-defined, physically distinct cotton-like fibres of polymethyl methacrylate (PMMA) with the incorporation of 0.39 wt% graphene oxide (GO). So-fabricated cotton-like distinct single fibres were extensively characterised by employing advanced techniques like high-resolution transmission electron microscopy (HRTEM) to study the internal structure and atomic force microscopy (AFM) to evaluate the mechanical properties of the single fibres at the nanoscale to overcome the ambiguities associated with the conventional mechanical property testing for a fibrous mat. The studies revealed that the fibres produced were highly flexible (DMT modulus similar to 0.28 GPa) with exceptional thermo-mechanical performances and cryogenic stability. Also, the probable underlying mechanism and the molecular-level interaction of PMMA-GO have been discussed thoroughly. The biocompatibility of PMMA-GO single fibres has been examined by the cell viability test. The findings demonstrated that PMMA-GO fibres are non-toxic to cells at higher GO concentrations. Importantly, this study is directed towards the comprehensive characterisation of single electrospun fibres, thereby investigating their behaviour in a cryogenic (liquid nitrogen) environment.