摘要:
Systems and methods for thermally actuating piezoresistive cantilevers are described. One embodiment includes a nanoelectromechanical resonator connected in at least one location to a substrate, an electrically conductive path formed on the resonator and a signal source connected to the electrically conductive path and configured to provide an oscillating actuation signal capable of exciting a resonant mode in the resonator.
摘要:
A system containing a micro-mechanical or nano-mechanical device and a method of operating the same is provided. The device includes a resonator and a piezoresistive element connected to the resonator. The method includes AC biasing the piezoresistive element at a first frequency, driving the resonator at a second frequency different from the first frequency, and detecting a mechanical response of the resonator at one or both of a difference frequency and a sum frequency of the first and second frequencies.
摘要:
A system containing a micro-mechanical or nano-mechanical device and a method of operating the same is provided. The device includes a resonator and a piezoresistive element connected to the resonator. The method includes AC biasing the piezoresistive element at a first frequency, driving the resonator at a second frequency different from the first frequency, and detecting a mechanical response of the resonator at one or both of a difference frequency and a sum frequency of the first and second frequencies.
摘要:
A biosensor is comprised of a free and a biofunctionalized recognition self-sensing nanocantilever, a dock adjacent to the ends of the nanocantilevers, and a gap between the nanocantilevers and dock. The self-sensing cantilevers each include a semiconductor piezoresistor defined in a pair of legs about which the cantilevers flex. A bias power or current is applied to the piezoresistor. The sensitivity of the cantilevers is optimized for a given ambient temperature and geometry of the cantilevers and dock by minimizing the force spectral density, SF, of the cantilevers to determine the optimum bias power, Pin. A sub-aN/√Hz force sensitivity is obtained by scaling down the dimensions of the cantilevers and supplying an optimum bias power as a function of temperature and geometry.
摘要:
A doubly clamped beam has an asymmetric piezoelectric layer within the beam with a gate proximate to the beam within a submicron distance with a gate and beam dipole. A suspended beam is formed using a Cl2/He plasma etch supplied at a flow rate ratio of 1:9 respectively into a plasma chamber. A parametric amplifier comprises a NEMS signal beam driven at resonance and a pair of pump beams driven at twice resonance to generate a modulated Lorentz force on the pump beams to perturb the spring constant of the signal beam. A bridge circuit provides two out-of-phase components of an excitation signal to a first and second NEMS beam in a first and second arm. A DC current is supplied to an AC driven NEMS device to tune the resonant frequency. An analyzer comprises a plurality of piezoresistive NEMS cantilevers with different resonant frequencies and a plurality of drive/sense elements, or an interacting plurality of beams to form an optical diffraction grating, or a plurality of strain-sensing NEMS cantilevers, each responsive to a different analyte, or a plurality of piezoresistive NEMS cantilevers with different IR absorbers.