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MEMS piezoresistive pressure sensors are most widely explored for various applications such as industrial, automotive and medical field. Each application covers a wide operating range from very low pressure to the higher pressure. In this paper a novel structure is designed by introducing the local stiffness in the diaphragm membrane for low pressure measurement. Rod beams at the diaphragm with combination of graphene piezoresistors, improves overall performance of the pressure sensor in terms of sensitivity. At higher temperature and higher pressure, a noticeable sensitivity is achieved which is compared to the previous design of graphene pressure sensor without rod beam structure. At room temperature (25 °C), sensitivity of pressure sensor with rod beam structure is 6.28 mV/psi. At 30 °C, the sensitivity is 58% higher than sensitivity of pressure sensor without rod beam structure for low-pressure specific range.

This paper investigates the effect of %wt composition of BisGMA/TEGDMA, stirring time, bench time, curing time and filler loading on polymerization shrinkage and micro-hardness of resin based dental composites. The investigation was carried out in two stages. In first stage, samples were prepared with different %wt composition of BisGMA/TEGDMA, stirring time, bench time, and curing time to access the effect of different input parameters for minimum polymerization shrinkage and maximum micro-hardness using Taguchi methodology. Selecting optimum values of input factors from first stage, second stage optimization was performed to investigate the effects of different filler loading on different %wt composition of BisGMA/TEGDMA using full factorial design. Prediction model was developed using Design Expert software and analysis of effect of input parameters on output responses were carried out using 3D surface plots. ANOVA were performed to check the significance of prediction model. In first stage, optimum stirring time, bench time and curing time were found to be 4 h, 50 min and 30 s, respectively. In second stage, optimum polymerization shrinkage and micro-hardness of 3.54% and 310 Hv were predicted at 22.89% of TEGDMA content and 20% filler loading. Taguchi methodology and full factorial design were successfully implemented to access the effect of multi-input parameters on responses for resin based dental composites.

MEMS pressure sensor has shown a remarkable change in revenue collection during the year 2018. Due to recent growth in smart microsystem technology for automation systems, demand has grown substantially for sensors. High sensitivity, flexibility, miniaturization and bulk production are some of the key factors of a pressure sensor in achieving new heights in the MEMS market. In this paper, Graphene piezo resistive material has been analysed for pressure sensing elements and compared with Polysilicon in terms of sensitivity and sensor performance degradation at different temperature. MEMS pressure sensors using Polysilicon and Graphene piezo resistive materials were simulated on silicon (100) substrate by COMSOL Multiphysics 5.3a version. The simulation result shows that at room temperature polysilicon pressure sensor performs well with pressure sensitivity of 3.81 mV/psi as well as it is found that graphene pressure sensor also shows better results at room temperature showing a pressure sensitivity of 3.98 mV/psi. As on frequently increasing the temperature it is noticed that polysilicon pressure sensitivity degrades with a factor of 0.64 mV/psi. However, graphene pressure sensor shows very less variation in sensitivity at higher temperature. Although it shows a small increment of 0.02 mV/psi in the pressure sensitivity. This analysis opens the path to utilise the graphene pressure sensor at high temperature.

The demand for flexible and wearable sensors is increasing day by day due to varied applications in the biomedical field. Especially highly sensitive sensors are required for the detection of the low signal from the body. It is important to develop a pressure sensor that can convert the maximum input signal into the electrical output. In this paper, the design and performance of graphene piezoresistive pressure sensors have been investigated by zig–zag piezoresistors on the square diaphragm. On the applied pressure, deformation is sensed by the piezoresistors above the diaphragm. Finite element analysis is carried out to investigate the effect of zig–zag piezoresistors on the square diaphragm. Simulated results for the optimized design are obtained for an operating range of 0–100 psi for pressure sensitivity.

In this study, BisGMA, TEGDMA as monomers were used to fabricate dental composites. Camphorquinone was used for photopolymerization using LED light curing unit. To prepare filled resin based dental composites, different %wt (5%, 10%, 15%, 20%) of nanoalumina were used. Unfilled and filled samples were prepared for polymerization shrinkage test, compressive strength test and void content test. Different samples were tested and it is revealed that polymerization shrinkage is diminishing with increase in filler content while compression strength and void content are increasing with increase in filler content.

In all the arithmetic operations, addition is one of the most important and initial operations used in most of the mathematical equations. The operation is performed by many adders present in the digital world. These adders give us carries with preferred delay and power. The three main features like structure, logic, and compact circuit layout help design a better adder. This Paper aims to analyse and compare various additions for high-speed, low-power and fast calculation. The various adder designs seen in digital signal processing applications require computationally efficient adding and cumulative operations, so blocks with the required attributes must be carefully selected. Various techniques have been proposed to design efficient adders in terms of performance, low power consumption and area. This work focused on 16-bit implementations of highly optimized area-efficient Ripple Carry Adders (RCA) and Look Ahead Carry Adders (LAC), and carry select Adder. Finally, we can prove that the Carry look ahead Adder is very fast in all existing designs. These processes are simulated and synthesized in all ISE Xilinx 14.7 software.

This paper investigates the effect of diaphragm thickness, dimensions of piezoresistors, doping profile and temperature compatibility on sensitivity and non-linearity of graphene MEMS pressure sensor. Taguchi method is used for maximizing the sensitivity and minimizing the nonlinearity of the designed pressure sensor. L27 orthogonal array is utilized for five input factors with three levels. Output voltage is obtained from simulation in COMSOL for different combinations of the input parameters as per L27 orthogonal array. It was found that diaphragm thickness and length of the sensing element shows maximum contribution in increasing the sensitivity of the pressure sensor. Similarly, interaction of diaphragm thickness with piezoresistors thickness and doping concentration shows a major contribution in reducing the non-linearity of the pressure sensor. Other factors such as operating temperature affects both sensitivity and nonlinearity of the pressure sensor with a very low contributing percentage of 0.40% and 2.16%, respectively. Pareto Analysis of variance (ANOVA) was employed to validate the predicated results of the designed pressure sensor. The result indicated that the optimum design shows a sensitivity of 4.10 mV/psi with very low non linearity of 0.1%.

Demand of MEMS sensor is increasing due to its applicability in various fields such as in automobile and industrial applications. Save driving is very necessary which can be properly accomplish by usage of flexible MEMS devices which can monitor different parameters such as tyre pressure, speed etc. Tyre pressure monitoring system consists of flexible MEMS pressure sensor, which provide low power consumption and temperature compatibility by proper selection of the sensor material. In this paper, modelling of graphene based flexible piezoresistive pressure sensor has been carried out for monitoring of the tyre pressure. Graphene is used as a substrate material, which makes the flexible device that can be implanted easily in the tyre. Graphene is also used as the sensing material for piezoresistors. Results indicate that sensitivity of 0.63 mV/kPa is achieved at room temperature.

Demand of plastic is increasing at a rapid rate in India and across globe. Plastic is processed using plastic injection molding machine. In this article, plastic injection molding process and injection molding system is discussed in detail. Various factors which may affect the quality of product during production through plastic injection molding is also discussed. Defect in plastic injection molded product has also been discussed.

In this paper, sensitive piezoresistive graphene pressure sensor is designed and analysed for applications in field of biomedical for healthcare devices. The relationship between applied pressure and output voltage was studied by finite element modelling and simulation method in COMSOL. The results show that sensitivity of 3.89 mV/psi is achieved on application of 0–100 psi pressure. The effect of frequency variation on sensitivity is also investigated for this pressure sensor. Nonlinearity is calculated as a function of applied pressure and obtained output voltage. Linear behaviour is noticed between 40 and 90 psi.

This review article compiles the characteristics of resin based dental composites and an effort is made to point out their future perspectives. Recent research studies along with few earlier articles were studied to compile the synthesis schemes of commonly used monomers, their characteristics in terms of their physical, mechanical and polymerization process with selectivity towards the input parameters of polymerization process. This review covers surface modification processes of various filler particles using silanes, wear behaviour, antimicrobial behaviour along with its testing procedures to develop the fundamental knowledge of various characteristics of resin based composites. In the end of this review, possible areas of further interests are pointed out on the basis of literature review on resin based dental materials. Keywords: Dental composites, Surface modification of filler particles, Wear, Self-healing, Antimicrobial properties

In this paper, stress and eigen frequencies are analyzed through prediction of microcantilever model using design of experiment approach. The important factors affecting displacement sensitivity, stress and eigen frequencies were identified such as geometrical dimensions of microcantilever (length, breadth and thickness), modulus of elasticity of materials, applied force. Based on the selection of factors and levels, experiments were designed using L9 orthogonal array. The designed experiments were simulated with finite element method in COMSOL Multiphysics software. Further, optimum values of dimensions of microcantilever and material property are used for stress and eigen frequencies analysis. The evaluated frequencies under eigen frequency analysis revealed that designed and simulated Gallium Arsenide (GaAs) microcantilever is prone to vibrate at these frequencies, whereas stress analysis illustrates the response of structure and material properties towards reliability.