Optical trapping and manipulation of micrometre-sized particles was first reported in 1970. Since then, it has been successfully implemented in two size ranges: the subnanometre scale, where light-matter mechanical coupling enables cooling of atoms, ions and molecules, and the micrometre scale, where the momentum transfer resulting from light scattering allows manipulation of microscopic objects such as cells. But it has been difficult to apply these techniques to the intermediate - nanoscale - range that includes structures such as quantum dots, nanowires, nanotubes, graphene and two-dimensional crystals, all of crucial importance for nanomaterials-based applications. Recently, however, several new approaches have been developed and demonstrated for trapping plasmonic nanoparticles, semiconductor nanowires and carbon nanostructures. Here we review the state-of-the-art in optical trapping at the nanoscale, with an emphasis on some of the most promising advances, such as controlled manipulation and assembly of individual and multiple nanostructures, force measurement with femtonewton resolution, and biosensors.

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Optical trapping and manipulation of nanostructures

Optical trapping is an established field for movement of micron-size objects and cells. However, trapping of metal nanoparticles, nanowires, nanorods and molecules has received little attention. Nanoparticles are more challenging to optically trap and they offer ample new phenomena to explore, for example the plasmon resonance. Resonance and size effects have an impact upon trapping forces that causes nanoparticle trapping to differ from micromanipulation of larger micron-sized objects. There are numerous theoretical approaches to calculate optical forces exerted on trapped nanoparticles. Their combination and comparison gives the reader deeper understanding of the physical processes in an optical trap. A close look into the key experiments to date demonstrates the feasibility of trapping and provides a grasp of the enormous possibilities that remain to be explored. When constructing a single-beam optical trap, particular emphasis has to be placed on the choice of imaging for the trapping and confinement of nanoparticles.

https://www.spiedigitallibrary.org/journals/Journal-of-Nanophotonics/volume-2/issue-1/021875/Optical-manipulation-of-nanoparticles-a-review/10.1117/1.2992045.pdf

Optical manipulation of nanoparticles: a review

To provide a power storage device, an operation condition of which is easily analyzed. A secondary battery includes a sensor that is a measurement unit, a microcontroller unit that is a determination unit, and a memory that is a memory unit. With the sensor, conditions of the secondary battery such as the remaining battery power, the voltage, the current, and the temperature are measured. The microcontroller unit performs arithmetic processing of the measurement results and determines the operation condition of the secondary battery. Further, the microcontroller unit stores the measurement result in the memory in accordance with the operation condition of the secondary battery.

Power storage device and power storage system

According to one embodiment, a nonaqueous electrolyte battery is provided. The battery includes a positive electrode, a negative electrode, and a nonaqueous electrolyte. The positive electrode includes lithium iron phosphate having an olivine structure as positive electrode active material. The negative electrode includes lithium titanate having a spinel structure and a monoclinic β-type titanium complex oxide as a negative electrode active material.

Nonaqueous electrolyte battery and battery pack

We demonstrate optical alignment and rotation of individual plasmonic nanostructures with lengths from tens of nanometers to several micrometers using a single beam of linearly polarized near-infrared laser light. Silver nanorods and dimers of gold nanoparticles align parallel to the laser polarization because of the high long-axis dipole polarizability. Silver nanowires, in contrast, spontaneously turn perpendicular to the incident polarization and predominantly attach at the wire ends, in agreement with electrodynamics simulations. Wires, rods, and dimers all rotate if the incident polarization is turned. In the case of nanowires, we demonstrate spinning at an angular frequency of ∼1 Hz due to transfer of spin angular momentum from circularly polarized light.

Alignment, Rotation, and Spinning of Single Plasmonic Nanoparticles and Nanowires Using Polarization Dependent Optical Forces

High capacity silicon based anode active materials are described for lithium ion batteries. These materials are shown to be effective in combination with high capacity lithium rich cathode active materials. Supplemental lithium is shown to improve the cycling performance and reduce irreversible capacity loss for at least certain silicon based active materials. In particular silicon based active materials can be formed in composites with electrically conductive coatings, such as pyrolytic carbon coatings or metal coatings, and composites can also be formed with other electrically conductive carbon components, such as carbon nanofibers and carbon nanoparticles. Additional alloys with silicon are explored.

High capacity anode materials for lithium ion batteries

Positive electrode active materials are formed with various metal oxide coatings. Excellent results have been obtained with the coatings on lithium rich metal oxide active materials. Surprisingly improved results are obtained with metal oxide coatings with lower amounts of coating material. High specific capacity results are obtained even at higher discharge rates.

Metal oxide coated positive electrode materials for lithium-based batteries

Positive electrode active materials are described that have a very high specific discharge capacity upon cycling at room temperature and at a moderate discharge rate. Some materials of interest have the formula Li1+xNiαMnβCoγO2, where x ranges from about 0.05 to about 0.25, α ranges from about 0.1 to about 0.4, β ranges from about 0.4 to about 0.65, and γ ranges from about 0.05 to about 0.3. The materials can be coated with a metal fluoride to improve the performance of the materials especially upon cycling. Also, the coated materials can exhibit a very significant decrease in the irreversible capacity lose upon the first charge and discharge of the cell. Methods for producing these materials include, for example, a co- precipitation approach involving metal hydroxides and sol-gel approaches.

Positive electrode materials for lithium ion batteries having a high specific discharge capacity and processes for the synthesis of these materials

Optical trapping and manipulation of individually dissolved single-walled carbon nanotubes in an aqueous solution was demonstrated using an infrared laser trapping system. The trapping effect was attributed to the interaction between the electric field of the laser and the instantaneously induced dipole moments in individual nanotube molecules. Fluorescence microscopy and intensity measurements demonstrated that the amount of trapped nanotubes is dependent on the initial nanotube concentration, laser power, and irradiated volume of the laser beam. It was also demonstrated that an optical trap combined with a microfluidic device trapped and moved nanotubes in the fluid channel.

Optical Trapping of Single-Walled Carbon Nanotubes

Lithium rich and manganese rich lithium metal oxides are described that provide for excellent performance in lithium-based batteries. The specific compositions can be engineered within a specified range of compositions to provide desired performance characteristics. Selected compositions can provide high values of specific capacity with a reasonably high average voltage. Compositions of particular interest can be represented by the formula, x Li2MnO3 • (1-x) Li Niu+ΔMnu-ΔCowAyO2. The compositions undergo significant first cycle irreversible changes, but the compositions cycle stably after the first cycle.

Herman A. Lopez

Papers

High capacity anode materials for lithium ion batteries

Metal oxide coated positive electrode materials for lithium-based batteries

Positive electrode materials for lithium ion batteries having a high specific discharge capacity and processes for the synthesis of these materials

Optical Trapping of Single-Walled Carbon Nanotubes

Layer-layer lithium rich complex metal oxides with high specific capacity and excellent cycling