TY - GEN
T1 - Feedback delays for ultrasensitive sensing
AU - Daqaq, Mohammed F.
AU - Jalili, Nader
AU - Bradley, Calvin
AU - Alhazza, Khaled
PY - 2008
Y1 - 2008
N2 - Nanomechanical Cantilever Sensors (NMCS) have recently emerged as an effective means for label-free chemical and biological species detection. Their high selectivity, low cost, and easy mass production make them an enabling technology for micro- and nanodetection techniques. Sensitivity constitutes one of the most desirable characteristics of NMCS. However, sensitivity of current NMCS is predominately limited by their size. In other words, smaller sensors are more sensitive than larger ones. The detection of ultra-small masses or frequency variations is therefore obstructed by the availability of more advanced fabrication techniques that are capable of manufacturing smaller and smaller sensors. Even in that case, other issues such as noise, damping, and measurement difficulties become more evident. Therefore, techniques for sensitivity enhancement should be studied and implemented to allow for accurate and precise detection of even smaller parameter variations. Along that line of reasoning, we propose a simple, but effective concept to enhance sensitivity of NMCS. The proposed methodology is based on utilizing feedback delays to create a limit-cycle response whose amplitude is ultra-sensitive to frequency variations. In this paper, we explain, analyze, and derive the equations that verify the proposed concept. We then experimentally implement the sensitivity enhancement technique on a macrocantilever beam and demonstrate more than two-orders-of-magnitude sensitivity enhancement over the frequency-shift method.
AB - Nanomechanical Cantilever Sensors (NMCS) have recently emerged as an effective means for label-free chemical and biological species detection. Their high selectivity, low cost, and easy mass production make them an enabling technology for micro- and nanodetection techniques. Sensitivity constitutes one of the most desirable characteristics of NMCS. However, sensitivity of current NMCS is predominately limited by their size. In other words, smaller sensors are more sensitive than larger ones. The detection of ultra-small masses or frequency variations is therefore obstructed by the availability of more advanced fabrication techniques that are capable of manufacturing smaller and smaller sensors. Even in that case, other issues such as noise, damping, and measurement difficulties become more evident. Therefore, techniques for sensitivity enhancement should be studied and implemented to allow for accurate and precise detection of even smaller parameter variations. Along that line of reasoning, we propose a simple, but effective concept to enhance sensitivity of NMCS. The proposed methodology is based on utilizing feedback delays to create a limit-cycle response whose amplitude is ultra-sensitive to frequency variations. In this paper, we explain, analyze, and derive the equations that verify the proposed concept. We then experimentally implement the sensitivity enhancement technique on a macrocantilever beam and demonstrate more than two-orders-of-magnitude sensitivity enhancement over the frequency-shift method.
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U2 - 10.1115/DETC2007-35088
DO - 10.1115/DETC2007-35088
M3 - Conference contribution
AN - SCOPUS:44849117183
SN - 0791848027
SN - 9780791848029
SN - 0791848027
SN - 9780791848029
T3 - 2007 Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, DETC2007
SP - 743
EP - 750
BT - 2007 Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, DETC2007
T2 - 21st Biennial Conference on Mechanical Vibration and Noise, presented at - 2007 ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, IDETC/CIE2007
Y2 - 4 September 2007 through 7 September 2007
ER -