Nanomechanical resonators

Figure 1. A nanomechanical resonator the thin central bar is coated with a conductor (gold) which also forms the T-shaped control electrode to the left. The thin line parallel to the resonator is the central island of a single-electron transistor which serves as the position sensor. 

Li, C. Chou, T. W. (2003). Single-Walled Carbon Nanotubes as Ultrahigh Frequency Nanomechanical Resonators. Phys. Rev. B, 68, 073405. 

Li CY, Chou TW (2004) Mass detection using carbon nanotube-based nanomechanical resonators. Appl Phys Lett 84 5246-5248... 

Sekaric L, et al. Nanomechanical resonant structnres in nanocrystalline diamond. Appl Phys Lett 2002. 

J. Arcamone, G. Rius, G. Abadal, J. Teva, N. Barniol, and F. Perez-Murano, Micro/nanomechanical resonators for distributed mass sensing with capacitive detection. Microelectron. Eng., 83,1216-1220 [2006]. 

Lavrik, N. V., Datskos, R G. (2003). Fem-togram mass detection using photothermally actuated nanomechanical resonators. Applied Physics Letters, 82, 2697-2699. 

J.H. Lee, K.S. Hwang, J. Park, K.H. Yoon, D.S. Yoon, and T.S. Kim, Immunoassay of prostate-specific antigen (PSA) using resonant frequency shift of piezoelectric nanomechanical microcantilever. Biosens. Bioelectron. 20, 2157-2162 (2005). 

The use of polymer-coated cantilevers such as microfabricated beams of silicon is becoming more popular as the basis of nanomechanical sensors [11]. These devices detect physical and chemical interactions between the reactive layer on the surface and the environment [8]. When the polymer interacts with a gaseous species, it swells and causes the cantilever to bend as a result of surface stresses when used in the static mode. In the dynamic mode, the cantilever acts as a microbalance, which responds to changes in resonance frequency. Savran s group at Purdue University has been researching the micromechanical detection of proteins by use of aptamer-based receptor molecules [12]. 

The known structures largely comprise the rod-like domain of the vimentin dimer, as illustrated in Fig. 3a. However, some segments have unknown structures. Experimental work using diffraction techniques has identified certain structural characteristics, and work based on Electron Paramagnetic Resonance measurements have revealed that the local stiffness of the LI and L2 domains (both helical structures) is close to that of the rod-like domain [65]. There appear to be persistent experimental challenges in identifying the remaining parts of vimentin IF structures. However, the intrinsic limitations in experimental methods call for the development of complementary computational methods that can provide a more controlled condition to assess the relation between the nanostructure and the nanomechanics of this class of materials. 

Badzey, R.L. Mohanty, R (2005). Coherent signal amplification in bistable nanomechanical oscillators by stochastic resonance. Nature, vol. 437, pp. 995-998. 

Several nanomechanical characterization techniques have been suggested to measure the elastic properties of individual electrospun nanofibers, such as AFM cantilevers, universal tensile tester, and AFM-based nanoindentation system [133, 134]. Among them AFM-based techniques have been widely used to measure the mechanical properties of single electrospun nanofibers. This technique was carried out by attaching nanofiber to two AFM cantilever tips and recording the cantilever resonances for both the free cantilever vibrations and for the case where the microcantilever system has nanofibers attached. The Young s modulus of the nanofiber is then derived from the measured resonant frequency shift resulting from the nanofiber. A similar experiment has been carried out for electros-... 

Nanomechanical, electtonmagnetic devices, resonators, composite materials... 

Because AFM is based on forces between the nanoprobe tip and the surface, the method is inherently suited to analyze mechanical properties of polymers. This has been realized experimentally very early [35]. For polymers, the determination of nanomechanical response of polymers, measurements of viscoelasticity by contact resonance force microscopy [36] and AFM nanorheology [37] have been reported. These more specialized modes are not further discussed as they are not considered to be standard methods. 

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