PIEZORESISTIVE DETECTION RESONANT DEVICE WITH LARGE VIBRATION AMPLITUDE
Data di pubblicazione
Data di priorità
Politecnico di Milano; CEA-LETI
Department of Electronics, Information and Bioengineering
Giacomo Langfelder; Longoni Antonio; Stefano Dellea; Patrice Rey; Guillaume Jourdan; Philippe Robert
At the state of the art there exist devices to detect inertial forces, which rely on piezoresistive miniaturized gauges, however, they can only detect small displacements.
The invention proposes the use of piezoresistive sensing elements based on NEMS (nanoelectromechanical systems) gauges for resonators, whose displacements can be relatively large compared to the typical displacement range of the field. The goal is achieved by using a vibrational mass connected to a substrate through flexural springs, which decouple the large motion of the mass from the relatively small motion at the nano gauge tip.
The direct advantage of using this type of sensing in resonators or in resonant sensors (e.g. gyroscopes) is the elimination of capacitive coupling issues.
Campo di applicazione
Detection of large displacements in micro devices , resonant and not through nano piezoresistive gauge . The application concerns the fields of sensors consumer , automotive , medical and industrial
In most of state-of-the-art solutions, the detection of large displacement is performed with capacitive sensors (comb fingers). This detection mechanism suffers from low output signal, and therefore from a large impact of capacitive couplings of spurious harmonics. This issue is bypassed by using piezoresistive readout, as proposed in the present invention. Further, compared to capacitive readout, piezoresistive readout enables the design of electronic circuit with a lower power consumption.