We describe resonant capacitive MEMS transducers developed for use as acoustic emission detectors, fabricated in the commercial three-layer polysilicon surface micromachining process (MUMPs). The 1-cm square device contains six independent transducers in the frequency range between 100 kHz and 500 kHz, and a seventh transducer at 1 MHz. Each transducer is a parallel plate capacitor with one pla...

in this study we investigate the effect of atoms such as b, n, ge and sn on the optical and the electrical properties of capped (5, 0) zigzag carbon nanotube, using dft calculation method. these elements were attached to the one end of the carbon nanotube. we considered four different structure designs as possible candidates for a p-n junction device. the electrical properties of these structur...

Tunable filters for wavelength-division multiplexing transmission system are essential. Fiber Bragg grating (FBG) is one of the best candidates for this application. The wavelength shift of FBGs can be tuned by applying different temperature, hydrostatically pressure and strains (in traction or/and compression). A comprehensive study of using these three parameters as being tunable filters was ...

Based on investigations with an ESEC thermosonic wire bonder, we report a novel ultrasound calibration method which consists of measuring in-situ the friction heat generated by the gold ball as it scrubs on the oxide of an integrated microsensor. This procedure can be carried out in-process using a dedicated testchip and a modiÞed clamping plate. The calibration dependence on the process parame...

This thesis presents a new approach to reading out thermal-conductivitybased gas sensors. This method is intended for the readout of a CMOScompatible resistive thermal-conductivity transducer for indoor CO2 sensing applications, without requiring precision off-chip components. Instead of accurately regulating the power dissipated in the transducer and measuring its temperature, the temperature ...

torque, speed, and power as mechanical variables are associated with the functional performance of any rotating machinery. the real-time performance and the efficiency of a machine can be determined with on-line measurement of these parameters. in this investigation a rotary torque meter (transducer) was constructed from strain gauge sensors for measuring the torque of rotating shafts. the syst...

In this work we report on the fabrication process for the development of a flexible piezopolymeric transducer for health monitoring applications, based on lead-free, piezoelectric zinc oxide (ZnO) thin films. All the selected materials are compatible with the space environment and were deposited by the RF magnetron sputtering technique at room temperature, in view of preserving the total flexib...

Ultrasound modulated light for optical tomography is very useful, since it can provide three-dimensional data with minimal mathematical processing. Although several experimental studies have shown the potential of this method, the link between the ultrasound location and the modulated signal intensity at the detector is not yet fully understood. We derive an analytical formula relating the posi...

Imaging the transverse vibrations of a resonating optical fibre cantilever is shown to be an effective method for generating 1D and 2D laser line scans. The resonant bending modes were excited by mounting a short length of 0.633μm single mode optical fibre on to a commercially available piezo-electric transducer. For an applied sinusoidal driving voltage of 20V pk-pk, the maximum displacement a...