Search results

The purpose of the study is to explore the potential possibility of using the conductive and piezoresistive nanocomposites that consist of insulating poly(dimethylsiloxane), a very popular silicone polymer, and the amazing properties of carbon nanotubes (CNT) in sensing applications. This nanocomposite is prepared by an optimized process to achieve a high-quality nanocomposite with uniform properties.

The optimized process achieved in this study to provide PDMS/CNT nanocomposite includes the appropriate use of ultrasonic bath, magnetic stirrer, molding and curing in certain circumstances that results in obtaining high-quality nanocomposite with uniform properties. Experiments to characterize the influence of some factors such as pressure, temperature and the impact of CNT’s concentration on the electrical properties of the prepared nanocomposite have been designed and carried out.

The obtained preparing method of this nanocomposite is found to have better homogeneity in comparison to other methods for CNT/PDMS nanocomposite. This nanocomposite has both desirable properties of the PDMS elastomer and the additional conductive CNT, and it can be used to create all-polymer systems. Furthermore, the conductivity values of these nanocomposites can be changed by varying some factors such as temperature and pressure, so that those can be used in temperature- and pressure-sensoring applications.

In the present research, a convenient, inexpensive and reproducible method for preparing CNT/PDMS nanocomposite was investigated. These nanocomposites with the unique properties of both PDMS elastomer and CNTs and also with high electrical conductivity, piezoresistive properties and temperature dependent resistivity can be used in different sensoring applications.

The purpose of this paper is to develop a program based on three‐dimensional finite element analysis to model different patterns of capacitive proximity sensors. This program can be used as a development tool to optimize the structure and size of a sensor for a desired or for a given sensitivity and linearity range and as a consequence to save sensor design time. A set of experiments have been conducted to test the tool capabilities for designing different sensor structures.

Finite element analysis in ANSYS software was used to perform electrostatic field simulations and to calculate the capacitance between electrodes of a capacitive proximity sensor when a conducting target is placed in some distance from the sensor plate.

Several capacitive proximity sensor structures have been designed, analyzed and tested to illustrate the accuracy of the simulated results obtained from the design tool. After design and implementation of a sensor and comparing the extracted and measured capacitance values, it is shown that the finite element analysis is an accurate method to extract fringing capacitance in capacitive proximity sensors in comparison to the analytical tool based on the finite difference method.

This automatic capacitive proximity sensor design tool can optimize a sensor structure with specific shape and size to have more sensitivity or linearity according to the application in use. Moreover, the modeling program can extract characteristics of a sensor with user‐defined parameters.