Manipulation Of Nano-objects Research Articles

Special Section Guest Editorial: Diffractive Optics and Nanophotonics

Manipulation of optical fields by micro- and nanostructured media has undergone millions of years of evolution. The structural color identified in some animals is one example that permits the study of the role of light in ecosystems and its evolution history. To transfer this natural concept of subwavelength-structured optical interfaces to provide state-of-the-art optical systems, diffractive optics’ essential role must be thoroughly understood. Diffractive optics is widely recognized as an important growth area in modern optics. The successful insight into the field of optical engineering and photonics offered by diffractive optics proves tremendous advantages over conventional bulk optics. The increasing demands and desire to improve telecommunication, optical computing, consumer electronics, laser material processing, biomedical sciences, and manipulation of nano-objects through micro-optical systems have driven the advance in diffractive optics, which creates a large number of new avenues in optical research and new directions in nanophotonics research.

Resonance optical manipulation of nano-objects based on nonlinear optical response

Optical manipulation is a technique to control the mechanical motion of small objects by using electromagnetic radiation force. Optical tweezers are the most popular tool to trap and move microparticles suspended in a medium. Recent interest has been shifting to manipulating nano-objects considerably smaller than the wavelength of light. Since the radiation force exerted on nano-objects is extremely small, an innovative method is necessary to make this concept feasible. Utilizing the resonant optical response of the objects to electronic transitions is one of the promising ways to approach nanoscale optical manipulation, and several advances in this direction have been made recently. Despite experimental studies on resonance optical tweezers showing favorable results, conventional theories have been unable to explain the results though demonstrations of resonant manipulations for traveling and standing waves have shown favorable results. In the present article, we provide a perspective view of resonance optical manipulation based on nonlinear optical response that we have recently proposed. This idea coherently elucidates recently reported puzzling phenomena appearing in studies concerning resonance optical tweezers that contradict the conventional understanding of resonance optical trapping. Further, this concept opens up the possibility to develop potentially powerful manipulation techniques because the nonlinear optical response involves processes with considerably greater degrees of freedom than those of the linear optical response. As examples, we propose a method for trapping single organic molecules that is more effective than ever before, selectively pulling the molecules with a particular transition energy, and our proposed method allows for high-spatial-resolution optical manipulation beyond the diffraction limit.

Development of laminated nanocomposites on the bases of magnetic and non-magnetic shape memory alloys: Towards new tools for nanotechnology

Abstract New composite functional material with shape memory effect (SME) has recently been proposed and tested for actuation on microscale. The composite nanotweezers have been designed and tested in manipulation of nano-objects. This report presents the new experiments on shape memory alloy’s (SMAs) properties on submicron scale of dimensions and the development of the technology of nanomanipulation on their bases. The minimal thickness of shape memory layer that undergoes SME was experimentally estimated for Ti 2 NiCu alloy. Impact of the focused ion beam modification of SMA superficial layer on the shape memory properties of micro-sized samples is discussed. Composite actuator of Ni–Mn–Ga magnetic SMA with the size of 20 × 4 × 2 μm 3 was fabricated for the first time and its thermal actuation was experimentally demonstrated ( http://www.smwsm.org/microactuators/NiMnGa.html ).

Micro and nanotechnological tools for study of RNA

Micro and nanotechnologies have originally contributed to engineering, especially in electronics. These technologies enable fabrication and assembly of materials at micrometer and nanometer scales and the manipulation of nano-objects. The power of these technologies has now been exploited in analyzes of biologically relevant molecules. In this review, the use of micro and nanotechnological tools in RNA research is described.

Optoelectrofluidic Manipulation of Nanoparticles and Biomolecules

This paper presents optoelectrofluidic technologies for manipulation of nanoparticles and biomolecules. Optoelectrofluidics provides an elegant scheme for the programmable manipulation of particles or fluids in microenvironments based on optically induced electrokinetics. Recent progress on the optoelectrofluidic manipulation of nanoobjects, which include nanospheres, nanowires, nanotubes, and biomolecules, is introduced. Some potential applications of the optoelectrofluidic nanoparticle manipulation, such as nanoparticles separation, nanostructures manufacturing, molecular physics, and clinical diagnostics, and their future directions are also discussed.

Composite Au Nanostructures for Fluorescence Studies in Visible Light

We present results from composite plasmonic nanostructures designed to achieve the cascaded enhancement of electromagnetic fields at optical frequencies. Our structures comprise a small metallic nanodisc suspended above a larger disk. We probe the optical properties of these structures by coating them with a layer of a visible-light fluorophore and observing fluorescence signals with the help of scanning confocal microscopy. A 43 +/- 5-fold increase in the far-field fluorescence signal has been observed for two-tier composite nanostructures, when compared to the signal obtained from individual nanodiscs. Our results offer the prospect of using such nanostructures for field concentration, optical manipulation of nanoobjects, chemical and biological sensing.

Surface-plasmon-resonance enhancement: effects on optical trapping and manipulation of nano-objects

The utilization of the enhanced local field near trapped metallic nanoparticles due to surface-plasmon resonance (SPR) for the optical trapping of dielectric fluorescent nano-objects is of considerable interest for single-molecule manipulation. Theoretical calculations as well as experimental measurements show that even with moderate SPR based field enhancement factors, gradient force based trapping of fluorescent molecules would be rather difficult. While trapping of the fluorescent molecule at resonance wavelength showed decreased stiffness, at wavelengths far away from resonance, increase in stiffness was found which was attributed to interplay of SPR-enhanced absorption and gradient forces.

Development of Hybrid MEMS/FIB Processes and Applications of Three-pronged Active Nanotweezers For Manipulation of Nano Objects

AbstractWe report recent development of a three-probe micromachined nanomanipulator for manipulation and in-situ characterization of nanomaterials in scanning electron microscope (SEM). The nanomanipulator consists of three independent probes having thermal bimetallic actuators and nanoscopic end-effectors. Nanoscale end-effectors with sub-100-nm spacing are created using focused ion beam (FIB) milling to directly interface with nanoscopic objects (e.g., nanotubes, nanowires). Handling of individual carbon nanotubes (CNTs) was successfully realized with the nanomanipulator in an SEM.

PRESENCE: the sense of believability of inaccessible worlds

With the development of new instruments as telecommunication, teleoperation, computer representation tools, human beings are commonly in situation to perceive and act on spaces that are more and more distant or different from our physical world. These new tools raise nowadays the question of Presence of these distant spaces with a growing intensity. This question crosses disciplines as different as computer arts or nanosciences. Through two experimental situations in each of these fields, (1) the playing of a musical virtual instrument and (2) the manipulation of nano-objects, the paper analyses the minimal conditions that the computer models and the human–computer interactions have to satisfy to trigger the sense of presence of distant inaccessible objects, whatever they are. After examining the evolution of instrumental tools, machines and concepts from real means to televirtual ones via the teleoperation and telecommunication chains and via experiments for the investigated fields, the paper shows that the primary condition able to generate ab initio the sense of presence, should be the instillation of a minimal physical coherence in the representation of distant worlds, and the introduction of the “evoked matter” concept as a central paradigm for the Presence issue.

Optical Trapping and Manipulation of Nano-objects with an Apertureless Probe

We propose a novel way to trap and manipulate nano-objects above a dielectric substrate using an apertureless near-field probe. A combination of evanescent illumination and light scattering at the probe apex is used to shape the optical field into a localized, three-dimensional optical trap. We use the coupled-dipole method and the Maxwell stress tensor to provide a self-consistent description of the optical force, including retardation and the influence of the substrate. We show that small objects can be selectively captured and manipulated under realistic conditions.