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Biomimetic Nanowalkers
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
Nanomotors (or alternatively called molecular motors) are nanoscale machines capable of self-propelled directional motion driven by chemical fuels or other energy sources. Nanomotors are not just one more type of nanodevices or loosely defined nanomachines. Instead, nanomotors satisfy the strictest machine definition from modern engineering that separates heat engines from any earlier “machines.” Differing from any other devices, nanomotors and heat engines are both the basic enabling machine that combines such fundamental physical elements as energy conversion, force generation, and directional motion (i.e., precise control over space and time)—all within a single (molecular) system. The three physical elements—energy, force, spatial– temporal control—make possible many new machines and functions. It’s not accidental that the Great Industrial Revolution was triggered by heat engines but not any machines of earlier civilizations. Nanomotors further extend the spatial/motion control down to nanometers (i.e., the dimension of individual molecules), and extend the energy conversion to a single fuel molecule at a time (hence higher efficiency than heat engines based on massive fuel burning). Thus nanomotors are a key to machinize nanoscopic or molecular systems, as heat engines do for macroscopic systems to bring us into the machine civilization. Likewise, a nanotechnology without nanomotors is a rickshaw nanotechnology at best, whose prospect to materialize into the next industrial revolution is questionable.
Artificial Nanomachines and Nanorobotics
Published in Shaker A. Mousa, Raj Bawa, Gerald F. Audette, The Road from Nanomedicine to Precision Medicine, 2020
Alexandre Loukanov, Hristo Gagov, Seiichiro Nakabayashi
Molecular motors are nanometer-sized devices based on proteins, DNA, supramolecular self-assemblies, etc., which are involved in a wide range of physiological processes and are often described as the workhorses of the living cell [11]. These nanoscale devices are capable of converting energy (chemical, light, electrical, thermal) into mechanical movement and typically generate force in the piconewton range [12, 13]. In an effort to study and manipulate the complex operations of natural molecular motors, researchers have designed and created corresponding synthetic analogues. There are two general approaches for the designing of molecular nanomotors [14]. The first one is inspired by the existing classical mechanical machines in the macroscopic world and their scaling down to nanosize. For example, nanocars, molecular elevators, molecular wheelbarrows, molecular pistons, etc., were designed and synthesized to imitate the macroscopic machines at molecular level [15]. The second, approach, known as biomimetic, is to design synthetic nanomotor based on the concepts already established in nanotechnology, molecular biology and bioengineering. Its efficient design requires generation of sufficient forces to power the nanomotor and precise control of the produced motion. DNA-based self-assemblies are ideal building blocks for the creation of artificial nanomotors with mechanical functions, including nanotweezers, nanogears, motors, and nanowalkers as shown in Fig. 14.2.
Artificial Nanomachines and Nanorobotics
Published in Shaker A. Mousa, Raj Bawa, Gerald F. Audette, The Road from Nanomedicine to Precision Medicine, 2019
Alexandre Loukanov, Hristo Gagov, Seiichiro Nakabayashi
Molecular motors are nanometer-sized devices based on proteins, DNA, supramolecular self-assemblies, etc., which are involved in a wide range of physiological processes and are often described as the workhorses of the living cell [11]. These nanoscale devices are capable of converting energy (chemical, light, electrical, thermal) into mechanical movement and typically generate force in the piconewton range [12, 13]. In an effort to study and manipulate the complex operations of natural molecular motors, researchers have designed and created corresponding synthetic analogues. There are two general approaches for the designing of molecular nanomotors [14]. The first one is inspired by the existing classical mechanical machines in the macroscopic world and their scaling down to nanosize. For example, nanocars, molecular elevators, molecular wheelbarrows, molecular pistons, etc., were designed and synthesized to imitate the macroscopic machines at molecular level [15]. The second, approach, known as biomimetic, is to design synthetic nanomotor based on the concepts already established in nanotechnology, molecular biology and bioengineering. Its efficient design requires generation of sufficient forces to power the nanomotor and precise control of the produced motion. DNA-based self-assemblies are ideal building blocks for the creation of artificial nanomotors with mechanical functions, including nanotweezers, nanogears, motors, and nanowalkers as shown in Fig. 14.2.
Flapwise bending vibration analysis of rotary tapered functionally graded nanobeam in thermal environment
Published in Mechanics of Advanced Materials and Structures, 2019
Navvab Shafiei, Majid Ghadiri, Mohammad Mahinzare
In this paper, the transverse vibration of a rotating functionally graded tapered Euler–Bernoulli nanobeam in thermal environments at low temperature was investigated based on Eringen's nonlocal elasticity theory. A power function determines material distribution along thickness of nanobeam. It is considered that beam is made of SUS304 and Al2O3 as metal and ceramic phases, respectively. It is assumed that all mechanical properties of utilized materials change by temperature variation. Governing equation and boundary conditions are derived by utilizing Hamiltonian's principle. To get understandable results, derived equation is transformed into a nondimensional form by using a suitable change of variable. Validations are done by modifying DQM with available results of Eringen's nonlocal theory. Results are presented for cantilever (clamped-free) and propped cantilever (clamped-simply supported) through illustrations, which investigates the effects of variable cross section along length, length scale parameter, nondimensional angular velocity and FG index on nanobeam's vibrational behavior working in low-temperature environments. Unlike all conditions which increasing rate of thickness change decreases all frequencies, fundamental frequency of cantilever boundary condition has a different behavior with respect to cross-section change along length in which fundamental nondimensional frequency increases by increasing rate of thickness changes continuously. Briefly, results represented that increase in nondimensional angular velocity and FG index, causes increasing and decreasing the nondimensional frequencies, respectively. Also, with increasing nonlocal parameter and rate of thickness change, all frequencies except the fundamental frequency of cantilever nanobeam were decreased. The results of this article can be used to design nanoturbines, nanomotors and nanbalades. In total, it was observed that effective parameters have affect on the nondinmentional first, second and third frequencies are boundary condition, rate of thickness change along length, nonlocal parameter, FG-power index and angular velocity.