The present work analyzes theoretically and verifies the advantage of utilizing rectangular microcantilevers with long-slits in microsensing applications. The deflection profile of these microcantilevers is compared with that of typical rectangular microcantilevers under the action of dynamic disturbances. Various force-loading conditions are considered. The theory of linear elasticity for thin beams is used to obtain the deflection-related quantities. The disturbance in these quantities is obtained based on wave propagation and beam vibration theories. It is found that detections of rectangular microcantilevers with long-slits based on maximum slit opening length can be more than 100 times the deflections of typical rectangular microcantilevers. Moreover, the disturbance (noise effect) in the detection quantities of the microcantilever with long-slits is found to be always smaller than that of typical microcantilevers, regardless of the wavelength, force amplitude, and the frequency of the dynamic disturbance. Eventually, the detection quantities of the microcantilever with long-slits are found to be almost unaffected by dynamic disturbances, as long as the wavelengths of these disturbances are larger than 3.5 times the microcantilever width. Finally, the present work recommends implementation of microcantilevers with long-slits as microsensors in robust applications, including real analyte environments and out of laboratory testing.
References
[1]
Alkamine, S.; Barrett, R.C.; Quate, C.F. Improved atomic force microscope images using microcantilevers with sharp tips. Appl. Phys. Lett. 1990, 57, 316–318.
[2]
Arntz, Y.; Seelig, J.D.; Lang, H.P.; Zhang, J.; Hunziker, P.; Ramseyer, J.P.; Meyer, E.; Hegner, M.; Gerber, C. Label-free protein assay based on a nanomechanical cantilever array. Nanotechnology 2003, 14, 86–90.
[3]
Suri, C.R.; Kaur, J.; Gandhi, S.; Shekhawat, G.S. Label-free ultra-sensitive detection of atrazine based on nanomechanics. Nanotechnology 2008, 19, 235502–235600.
[4]
Calleja, M.; Nordstrom, M.; Alvarez, M.; Tamayo, J.; Lechuga, L.M.; Boisen, A. Highly sensitive polymer-based cantilever-sensors for DNA detection. Ultramicroscopy 2005, 105, 215–222.
[5]
Wu, G.; Ji, H.; Hansen, K.; Thundat, T.; Datar, R.; Cote, R.; Hagan, M.F.; Chakraborty, A.K.; Majumdar, A. Origin of nanomechanical cantilever motion generated from biomolecular interactions. Proc. Natl. Acad. Sci. USA 2001, 98, 1560–1564.
[6]
Khaled, A.-R.A.; Vafai, K.; Yang, M.; Zhang, X.; Ozkan, C.S. Analysis, control and augmentation of microcantilever deflections in bio-sensing systems. Sens. Actuators B 2003, 94, 103–115.
[7]
Boisen, A.; Thaysen, J.; Jensenius, H.; Hansen, O. Environmental sensors based on micromachined cantilevers with integrated read-out. Ultramicroscopy 2000, 82, 11–16.
[8]
Zuo, G.; Li, X.; Zhang, Z.; Yang, T.; Wang, Y.; Cheng, Z.; Feng, S. Dual-SAM functionalization on integrated cantilevers for specific trace-explosive sensing and non-specific adsorption suppression. Nanotechnology 2007, 18, doi:10.1088/0957-4484/18/25/255501.
[9]
Zhang, G.; Zhao, L.; Jiang, Z.; Yang, S.; Zhao, Y.; Huang, E.; Hebibul, R.; Wang, X.; Liu, Z. Suface stress-induced deflection of a microcantilver with various widths and overall microcantilever sensitivity enhancement via geometry modification. J. Phys. D Appl. Phys. 2011, 44, doi:10.1088/0022-3727/44/42/425402.
Lee, H.J.; Chang, Y.S.; Lee, Y.P.; Jeong, K.-H.; Kim, H.-Y. Deflection of microcantilever by growing vapor bubble. Sens. Actuators A 2007, 136, 717–722.
[12]
Jeon, S.; Jung, N.; Thundat, T. Nanomechanics of self-assembled monolayer on microcantilever sensors measured by a multiple-point deflection technique. Sens. Actuators B 2007, 122, 365–368.
[13]
Yang, M.; Zhang, X.; Vafai, K.; Ozkan, C.S. High sensitivity piezoresistive cantilever design and optimization for an analyte-receptor binding. J. Micromech. Microeng. 2003, 13, 864–872.
[14]
Vafai, K.; Ozkan, C.; Haddon, R.; Khaled, A.-R.A.; Yang, M. Microcantilevers for Biological and Chemical Assays and Methods of Making and Using Thereof. U.S. Patent 7,288,404, 30 October 2007.
[15]
Zhu, Q.; Shih, W.Y.; Shih, W.-Y. Enhanced detection resonance frequency shift of a piezoelectric microcantilever sensor by a DC bias electric field in humidity detection. Sens. Actuators B 2008, 138, 1–4.
[16]
Yen, Y.-K.; Huang, C.-Y.; Chen, C.-H.; Hung, C.-M.; Wu, K.-C.; Lee, C.-K.; Chang, J.-S.; Lin, S.; Huang, L.-S. A novel, eclectically protein-manipulated microcantilever biosensor for enhancement of capture antibody immobilization. Sens. Actuators B 2009, 141, 498–505.
[17]
Ansari, M.Z.; Cho, C. Deflection, Frequency, and Stress Characteristics of Rectangular, Triangular, and Step Profile Microcantilevers for Biosensors. Sensors 2009, 9, 6046–6057.
[18]
Vafai, K.; Khaled, A.-R.A. Innovative biosensors for chemical and biological assays. U.S. Patent 7,695,951, 13 April 2010.
[19]
Khaled, A.-R.A.; Vafai, K. Optimization modelling of analyte adhesion over an inclined microcantilever-based biosensor. J. Micromech. Microeng. 2004, 14, 1220–1229.
[20]
Khanafer, K.; Khaled, A.-R.A.; Vafai, K. Spatial optimization of an array of aligned microcantilever based sensors. J. Micromech. Microeng. 2004, 14, 1328–1336.
[21]
Khanafer, K.; Vafai, K. Geometrical and flow configurations for enhanced microcantilever detection within a fluidic cell. Int. J. Heat Mass Transf. 2005, 48, 2886–2895.
[22]
Vafai, K.; Khaled, A.-R.A. Methods and devices comprising flexible seals, flexible microchannels, or both for modulating or controlling flow and heat. U.S. Patent 7,770,809, 10 August 2010.
[23]
Khaled, A.-R.A.; Vafai, K. Analysis of Deflection Enhancement Using Epsilon Assembly Microcantilevers Based Sensors. Sensors 2011, 11, 9260–9274.
[24]
Rao, S.S. Mechanical Vibrations, 5th ed. ed.; Addison-Wesley: New York, NY, USA, 2010.
[25]
Sader, J. Frequency response of cantilever beams immersed in viscous fluids with applications to the atomic force microscope. J. Appl. Phys. 1998, 84, 64–76.
