in this paper, design and construction of a tactile sensor for measuring contact-force is presented. mechanism of measuring contact-force in this tactile sensor is based on impedance changing of piezoelectric crystal and voltage of different points in circuit as a result of applying force on the crystal. by considering a specific point in the circuit and recording the changes of its voltage, ma...

An in-line chemical gas sensor was proposed and experimentally demonstrated using a new C-type fiber and a Ge-doped ring defect photonic crystal fiber (PCF). The C-type fiber segment served as a compact gas inlet/outlet directly spliced to PCF, which overcame previous limitations in packaging and dynamic responses. C-type fiber was prepared by optimizing drawing process for a silica tube with a...

Flexible pressure sensors are increasingly being used in medical and non-medical applications, and particularly in innovative health monitoring. Their efficacy in medical applications such as compression therapy depends on the accuracy and repeatability of their output, which in turn depend on factors such as sensor type, shape, pressure range, and conformability of the sensor to the body surfa...

The electrochemical sensor for detecting hydrogen sulfide was fabricated. H2S gas molecules pass through polytetrafluoroethylene membrane with 0.22 mm pore size. Carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) were used to fabricate working and counter electrodes. It can be seen from Field Emission Scanning Electron Microscopy (FESEM) images of the working electrode that...

Surveillance of large terrains using limited sensor capabilities is a challenging task in many military applications. In this paper, we present a new method to determine the number, type and location of sensor platform systems to effectively cover a large terrain, which is composed of areas of varying importance. A sensor platform system is an integrated system that consists of a platform (huma...

The study proposes a small U-shaped bending-induced interference optical fiber sensor; this novel sensor is a probe-type sensor manufactured using a mechanical device, a heat source, optical fiber and a packaging module. This probe-type sensor overcomes the shortcomings of conventional optical fibers, including being difficult to repair and a tendency to be influenced by external forces. We man...

Wireless Sensor Networks (WSNs) is a collection of thousands of tiny nodes that are capable of sensing, computing, and wireless communications. Energy consumption is the major design issue which arises while designing routing protocols for wireless sensor network. . Since wireless sensor network protocols are application specific, so the focus has been given to the routing protocols that might ...

a wireless sensor network consists of many inexpensive sensor nodes that can be used toconfidently extract data from the environment .nodes are organized into clusters and in each cluster all non-cluster nodes transmit their data only to the cluster-head .the cluster-head transmits all received data to the base station .because of energy limitation in sensor nodes and energy reduction in each d...