Doubly Clamped Nanobeam as a Piezoresistive Mass Sensor

In this paper, we present a novel technology to realize a doubly clamped nanobeam, which is preferred to cantilever because of its higher natural frequency with a same dimension, as a piezoresistive mass sensor. Ar selective bombardment was applied on a 200 nm thick doubly clamped nanobeam to form a piezoresistor in a Wheaston bridge along with other ordinary resistors. The device was electrostatically actuated and readout piezoresistively. The achieved merit product of Q-factor and f₀ in air is as high as 3.5 times 10⁸ , which hints a better mass detection resolution compared with its counterpart of micro cantilever, while our approach is simple and easily controlled.