Abstract:
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, S F , of the cantilevers to determine the optimum bias power, P in . A sub-aN/VHz 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.
Abstract:
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 Cl 2 /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.
Abstract:
A neural probe is provided. The probe includes: a base that includes an optical demultiplexer, and one or more shanks extending from the base, with each shank including one or more waveguides. In the neural probe, the optical demultiplexer is optically connected to the one or more waveguides of each shank. A system including the neural probe and an optical multiplexer optically connected to the demultiplexer of the neural probe is also provided. Further, a method of emitting light from a neural probe is provided. The method includes receiving and demultiplexing multiplexed optical signals at a base of a neural probe, and emitting the demultiplexed optical signals from one or more shanks of the neural probe.
Abstract:
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.
Abstract:
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, S F , of the cantilevers to determine the optimum bias power, P in . A sub-aN/VHz 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.
Abstract:
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.
Abstract:
A doubly clamped beam (30) has an asymmetric piezoelectric layer within the beam with a gate (32) proximate to the beam within a submicron distance with a gate and beam dipole.
Abstract:
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.
Abstract:
A bioNEMS device comprises a piezoresistive cantilever having flexing legs of which attach the cantilever to a support and a biofunctionalized portion at the tip. A bias current applied to the legs is limited by a maximal acceptable temperature increase at the biofunctionalized tip. The length of the cantilever has a magnitude chosen to minimize background Johnson noise. A catalyzed receptor on the device binds to a ligand whose binding rate coefficient is enhanced. The catalyst lowers the receptor-ligand binding activation energy and is designed by forced evolution to preferentially bind with the ligand. A carrier signal is injected by a magnetic film disposed on the cantilever which is electromagnetically coupled to a source of the carrier signal. A plurality of NEMS fluidicly coupled transducers generate a plurality of output signals from which a collective output signal is derived, either by averaging or thresholding. The NEMS devices are disposed in microfluidic flow channels and fabricated in a membrane. A linking molecule is attached to the tip of the transducer and a fluffball attached to the linking molecule to increase damping.
Abstract:
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.