A wireless magnetoelastic micro-sensor array for simultaneous measurement of temperature and pressure

Magnetoelastic thick film sensors mechanically deform when subjected to a magnetic field impulse, launching elastic waves within the sensor the magnitude of which is greatest at the mechanical resonant frequency. As the sensors are magnetostrictive, the mechanical deformations launch magnetic flux that can be detected remotely. The characteristic resonant frequency of a magnetoelastic sensor, which is a function of the length, density, elasticity and Poisson's ratio of the sensor material, changes in response to temperature, pressure, ambient flow rate and, in combination with a mass changing, chemically responsive layer different analyte concentrations. By using an array of such sensors different environmental parameters can be simultaneously determined in a complex environment; we have designed and fabricated such an array for the simultaneous measurement of temperature and pressure.