In this paper, a low cost 3x3 coupler Mach-Zehnder interferometric optical fibre vibration sensor is proposed. Unlike traditional Mach-Zehnder interferometer with a strain free reference arm, two parallel optical fibres with different strain transfer sensitivity is adopted. With proper demodulation algorithm, the time rate of change of the strain can be computed from the light signal of the out...

For application in structural health monitoring, a folded patch antenna has been previously designed as a wireless sensor that monitors strain and crack in metallic structures. Resonance frequency of the RFID patch antenna is closely related with its dimension. To measure stress concentration in a base structure, the sensor is bonded to the structure like a traditional strain gage. When the ant...

Measurement and monitoring of temperature, humidity and strain variation are very requested in great fields and areas such as structural health monitoring (SHM) systems. Currently, the use of fiber Bragg grating sensors (FBGS) is very recommended in SHM systems due to the specifications of these sensors. In this paper, we present the theory of Bragg sensor, therefore we try to measure the effic...

Authors have proposed a method for detecting a friction coefficient between a planar object and an elastic finger-shaped sensor by only pressing the sensor against the object in our previous study. In the present study, an elastic finger-shaped sensor made of silicone rubber is designed and produced. First, geometry of the finger-shaped sensor is designed using finite element analysis (FEA). Re...

An ultra-high sensitive strain sensor is proposed. The sensing head, based on the post-processing of a fiber Bragg grating, is used to perform passive and active strain measurements. Both wavelength and full width half maximum dependences with the applied strain are studied for the passive sensor, where maximum sensitivities of 104.1 pm/με and 61.6 pm/με are respectively obtained. When combinin...