Simultaneous magnetic and electrostatic driving of microcantilevers

Experimental study of the effect of hydrodynamic coupling of micro-cantilever array on the dynamic response of micro-cantilever

“…To check the parasitic driving due to electrostatic coupling or proximity effects [23] between the cantilever and the substrate underneath, the operating-cantilever was driven by the same current level (20 mV) without magnets. The frequency response of the operatingcantilever by parasitic driving (without magnets) is much smaller than that by magnetic driving (with magnets).…”

Tunable mechanical resonator with aluminium nitride piezoelectric actuation

“…Due to the inherent high speed of the APD and the broad bandwidth of the detection electronics used, the system allows to measure frequencies above 2 MHz. This technique was previously tested with one-side clamped bars or cantilevers 21 ; it allowed us to detect the thermal motion of the cantilevers with root mean squared displacements below 10 -10 m. Unfortunately, the thermal motion of the doubly-clamped microbridges studied in this work is significantly below that value due to their higher stiffness. As the noise floor of the electronics lies above the thermal motion, only by applying some external driving was it possible to measure the mechanical response of the microbridges.…”

Feedback loops with electrically driven microcantilevers

“…A low cost oscillator obtained in this way is thus highly desirable, and to build one of these oscillating loops, the electrical signal of the time-varying position of the cantilever was obtained by laser interferometry 4 . A driving by a magnetic torque 5 proportional to the current of a solenoid was planned to close the oscillator loop, but studying the transfer function of this driving we found an unintentional electrostatic driving (ED) of the cantilevers in our setup 6 . This ED contaminated the loop making difficult (if not impossible at low cost) its self-oscillation exactly at f 0 , where the maximum slope of the phase-frequency transfer function of the cantilever leads to the best frequency stability of the oscillating mass sensor we are looking for.…”

“…1) due to its good thermal control of the cantilever temperature and we looked for another way to drive these AFM cantilevers while keeping in mind the future use of 1-D linear arrays of cantilevers and also 2-D ones. From the long working distance (several mm) and excellent phase control in the frequency range of interest 6 found for ED with the electrical arrangement of Fig. 1, we adopt it as the driving mechanism to close the loop of the readout oscillator to be built around each cantilever being scanned.…”

“…1, we adopt it as the driving mechanism to close the loop of the readout oscillator to be built around each cantilever being scanned. This ED that has proven to be a good driver for short working distances 2,7 and for long ones in the mm range 6 has been used to apply electrostatic forces to the cantilevers with a tight phase control (e.g. in phase or in quadrature with their displacement z).…”