This paper reports on the design and experimental verification of a new class of nanoscale gravimetric sensors based on ultra-thin-film AlN Contour-Mode Resonant Sensor (CMR-S) functionalized with ss-DNA and connected to a chip-based self-sustaining oscillator loop (fabricated in the ON Semiconductor 0.5 μm CMOS process) for direct frequency read-out. The 220 MHz oscillator based on the ultra-thin AlN CMR-S exhibits an Allan Variance of ∼20 Hz for 100 ms gate time. The sensor affinity for the adsorption of volatile organic chemicals such as 2,6 dinitroluene (DNT, a simulant for explosive vapors) is enhanced by functionalizing the top gold electrode of the device with a thiol-terminated single stranded DNA sequence (Thiol -5' CTT CTG TCT TGA TGT TTG TCA AAC 3') enabling the detection of concentrations as low as 1.5 part per billion (ppb). Disciplines Electrical and Electronics CommentsSuggested Citation: Matteo Rinaldi, Brandon Duick, Chiara Zuniga, Chengjie Zuo, and Gianluca Piazza.

Gianluca; , "Use of a single multiplexed CMOS oscillator as direct frequency read-out for an array of eight AlN Contour-Mode NEMS Resonant Sensors," Sensors, 2010 IEEE , vol., no., pp.2666-2670, 1-4 Nov. 2010 ©2010 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This paper reports on the first demonstration of a single multiplexed CMOS oscillator circuit employed as direct frequency readout for an array of 8 nanoscaled aluminum nitride Contour-Mode Resonant Sensors (CMR-S). In this first prototype 8 thin-film (250 nm) AlN CMR-S operating at 186 MHz were fabricated on the same chip and simultaneously wire-bonded to a Pierce-like oscillator circuit (fabricated in the ON Semiconductor 0.5 µm CMOS process) by means of 8 CMOS transmission gates addressed via a 3 bit on-chip decoder. The 8 CMR-S were simultaneously exposed to different concentrations of methanol (0.1-1% of the saturated vapor pressure) and their response was monitored in a time-multiplexed mode. Frequency shifts of 300 Hz corresponding to changes of mass per unit area of 7 ag/µm 2 were experimentally detected. Values of phase noise derived Allan deviation as low as 0.9 Hz were measured. Such Allan deviation translates in an estimated limit of detection of 21 zg/µm 2 . Disciplines Engineering | Engineering Science and Materials CommentsSuggested Citation: Rinaldi, Matteo; Zuniga, Chiara; Duick, Brandon; Piazza, Gianluca; , "Use of a single multiplexed CMOS oscillator as direct frequency read-out for an array of eight AlN Contour-Mode NEMS Resonant Sensors," Sensors, 2010 IEEE , vol., no., pp.2666-2670, 1-4 Nov. 2010. ©2010 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.