Vibration Detector based on GMR Sensors
Up to now, vibrations have been mostly sensed by measuring displacement, velocity and acceleration. The most common types of vibration sensors are piezoelectric, capacitive, null-balance, strain gage, optoelectronic, resonance beam or piezoresistive. We present a low cost and low power vibration detector based on the measurement of magnetic field variations induced in a recent SS501 GMR magnetic sensor, which has never been applied for that. Vibrations on small ferromagnetic pieces disturb the Earth's magnetic field. These weak perturbations can be detected and measured over the assumed constant Earth's magnetic field, which is uniform over a wide area. A novel array configuration of 3 half…
Enhanced thermoelectric properties of lightly Nb doped SrTiO3 thin films
Novel thermoelectric materials developed for operation at room temperature must have similar or better performance along with being as ecofriendly as those commercially used, e.g., BiTe, in terms of their toxicity and cost. In this work, we present an in-depth study of the thermoelectric properties of epitaxial Nb-doped strontium titanate (SrTiNbO) thin films as a function of (i) doping concentration, (ii) film thickness and (iii) substrate type. The excellent crystal quality was confirmed by high resolution transmission electron microscopy and X-ray diffraction analysis. The thermoelectric properties were measured by the three-omega method (thermal conductivity) and van der Pauw method (el…