Thermal Piezoresistive Back Action Enhancement Using an Innovative Design of Silicon Nanobeam

Over the last few years, Thermal Piezoresistive Back Action (TPBA) in biased silicon nanobeams has demonstrated its potential to control the quality factor of resonant sensors and its ability to reach self-sustained oscillations regime. This paper reports an innovative beam geometry to improve TPBA efficiency, which consists of a thermal plate embedded in a silicon nanobeam used to implement TPBA. The plate increases the thermal inertia of the beam and consequently its thermal time constant that directly enhances TPBA. As a result, the efficiency of TPBA is considerably enhanced and the DC-Current biasing threshold, required to reach self-sustained oscillations regime, is substantially reduced saving up to one order of magnitude on energy consumption. This kind of beam can supersede regular nanobeam in most nanobeam based devices to improve TPBA efficiency with negligible changes on their mechanical and electrical behaviors.