Dynamic range of nanoresonators with random rough surfaces in the presence of thermomechanical and momentum exchange noise

Abstract

Citation for published version (APA): Palasantzas, G. (2007). Dynamic range of nanoresonators with random rough surfaces in the presence of thermomechanical and momentum exchange noise. Applied Physics Letters, 91(2), [021901].

Influence of surface modification on the quality factor of microresonators

“…For consistency an analytical estimation of S total was performed. For this we used the rough area calculation 18,25,26 S rough /S smooth…”

“…16 Recently it was shown theoretically that random surface roughness affects the quality factor, limit to mass sensitivity, Allan variance, and dynamic range of resonators. 17,18 However, so far a systematic experimental study of the influence of surface roughness on the quality factor of resonators is still missing. This will be the topic of the present paper, where we explore the dependence of the Q factor on the surface morphology of commercial microcantilevers (Table I) at various gas pressures covering the whole range from the free molecular up to the continuous regime (ambient regime ∼1 atm).…”

“…14 In addition a variety of studies have shown that surface roughness influences the quality factor for operation in vacuum. [15][16][17][18] In Si nanowires with 45 nm beamwidths and 380 MHz resonating frequencies, the quality factor was decreased from ∼3000 to 500 by an increment of the surface area to volume ratio from ∼0.02 to 0.07. 15 Studies for SiC/Si resonators have shown that devices operational in the UHF/microwave regime had a low surface roughness (∼2.1 nm), while devices with rougher films (up to ∼7.1 nm)…”

Allan variance of frequency fluctuations due to momentum exchange and thermomechanical noises

“…9 Recently, random surface roughness was shown to affect the quality factor, the limit to mass sensitivity of nanoresonators, and their dynamic range. [10][11][12] In addition, another important quantity that is very often used to compare frequency standards and thus quantify frequency fluctuations is the dimensionless Allan variance ͑ A ͒. 6,13,14 The latter is defined in the time domain as the variance over time in the measured frequency of a source, where each measurement is averaged over a time interval A ͑with zero-dead time between measurement intervals͒.…”

Surface roughness influence on the quality factor of high frequency nanoresonators

“…13 Recently, within the molecular regime ͑molecule mean free path larger than the lateral nanoresonator dimensions͒, it was shown that random surface roughness can decrease the quality factor and dynamic range, and increase the limit to mass sensitivity. [14][15][16] Furthermore, under operation in dense fluid, a high resonance-frequency nanomechanical resonator generates a rapidly oscillating flow in the surrounding fluid environment. 10,11 Over a broad frequency ͑͒ and pressure ͑P͒ range explored, it was observed a sign of a transition from Newtonian to non-Newtonian flow at Ϸ 1 with a fluid relaxation time.…”