Characterization of silver–gallium nanowires for force and mass sensing applications


(a) A schematic diagram of the laser Doppler Vibrometer. (b) SEM image and (c) the measured displacement PSD of a thermally excited Ag2Ga NanoCantilever (NCL) as it clearly reveals the 2nd through 9th eigenfrequencies. The colored tick marks above the spectral peaks indicate the expected theoretical location of each eigenfrequency. (c-inset) NCL displacement detected by scanning the laser beam along the NCL.

 

High Sensitivity Deflection Detection of Nanowires




(a) The calculated local intensities as a 166 nm radius nanowire translates across the focus of a 632.8 nm wavelength Gaussian beam with a full width of 1044 nm, in air. (b) The profile of the simulated signal on the split photodiode as the Ag2Ga NanoCantilever is translated across the beam, in normalized ordinate units. The spot-NanoCantilever separations shown in (a) are marked with Roman numerals. (c) Optical layout of the detection scheme. (d) Scanning electron microscopy (SEM) image of a representative Ag2Ga Nanocantilever, with a magnified inset of the tip. This nanowire is 59 µm long, with a radius of 166 nm.


Imaging soft materials in fluids by Ag2Ga NanoCantilevers



Sub-Angstrom-resolution sensing of NanoCantilevers is leading the way to a gentle physical probe for surfaces of materials such as living cells.  (left) A conceptual drawing of the nanowire detection scheme. (right) Photo of a portion of the optics.


Visual force sensing with flexible nanowire buckling springs

Deflections of a polymer fiber with the nanoneedle. (a) Nanoneedle approaching fiber. (b) Minimum and (c) maximum deflections of the needle. Computed geometries of the needle (dashed lines) are superimposed on top of SEM images of the needle.


Mass and stiffness calibration of Ag2Ga NanoCantilvers using thermally driven vibration

(a) SEM images of an Ag2Ga NanoCantilever. (b) Schematic of a perfectly circular NanoCantilever vs an asymmetry NanoCantilevers, when the thermal vibration is detected by Laser Doppler Vibrometer (LDV). (c) Experimental power spectral density (PSD) measurements using an LDV of a typical NanoCantilever at various rotation angles.