Precise position and angular control of optical trapping and manipulation via a single vortex-pair beam

Author(s):

Jisen Wen, Binjie Gao, Guiyuan Zhu, DadongLiu, Li-GangWang

Abstract:

“Optical trapping and manipulation using structured laser beams now attract increasing attention in many areas including biology, atomic science, and nanofabrication. Here we propose and demonstrate experimentally the use of a single vortex-pair beam in two-dimensional optical trapping and manipulation. Using the focal properties of such vortex-pair beams, we successfully manipulate two spherical microparticles simultaneously, and obtain the precise position-control on the microparticles by adjusting the off-axis parameter of the vortex-pair beam. Furthermore, we also realize the high-precision angular-controllable rotation of cylindrical microrods by rotating the initial phase structure of such vortex-pair beams, which is like an optical wrench due to two focused bright spots at the focal plane of objective lens. Our experimental result provides an alternative manipulation of microparticles and may have potential applications in biological area, and optically driven micromachines or motors.”

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Publication: Optics and Lasers in Engineering
Issue/Year: Optics and Lasers in Engineering, Volume 148, 106773 (2022)
DOI: 10.1016/j.optlaseng.2021.106773

Metamachines of pluripotent colloids

Author(s):

Aubret, Antoine; Martinet, Quentin & Palacci, Jeremie

Abstract:

“Machines enabled the Industrial Revolution and are central to modern technological progress: A machine’s parts transmit forces, motion, and energy to one another in a predetermined manner. Today’s engineering frontier, building artificial micromachines that emulate the biological machinery of living organisms, requires faithful assembly and energy consumption at the microscale. Here, we demonstrate the programmable assembly of active particles into autonomous metamachines using optical templates. Metamachines, or machines made of machines, are stable, mobile and autonomous architectures, whose dynamics stems from the geometry. We use the interplay between anisotropic force generation of the active colloids with the control of their orientation by local geometry. This allows autonomous reprogramming of active particles of the metamachines to achieve multiple functions. It permits the modular assembly of metamachines by fusion, reconfiguration of metamachines and, we anticipate, a shift in focus of self-assembly towards active matter and reprogrammable materials.”

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Publication: Nature Communications
Issue/Year: Nature Communications, Volume 12; Number 1; 2021
DOI: 10.1038/s41467-021-26699-6

Towards non-blind optical tweezing by finding 3D refractive index changes through off-focus interferometric tracking

Author(s):

Landenberger, Benjamin; Yatish & Rohrbach, Alexander

Abstract:

“In modern 3D microscopy, holding and orienting arbitrary biological objects with optical forces instead of using coverslips and gel cylinders is still a vision. Although optical trapping forces are strong enough and related photodamage is acceptable, the precise (re-) orientation of large specimen with multiple optical traps is difficult, since they grab blindly at the object and often slip off. Here, we present an approach to localize and track regions with increased refractive index using several holographic optical traps with a single camera in an off-focus position. We estimate the 3D grabbing positions around several trapping foci in parallel through analysis of the beam deformations, which are continuously measured by defocused camera images of cellular structures inside cell clusters. Although non-blind optical trapping is still a vision, this is an important step towards fully computer-controlled orientation and feature-optimized laser scanning of sub-mm sized biological specimen for future 3D light microscopy.”

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Publication: Nature Communications
Issue/Year: Nature Communications, Volume 12; Number 1; 2021
DOI: 10.1038/s41467-021-27262-z

Singular Warped Beams Controlled by Tangent Phase Modulation

Author(s):

Funes, Gustavo; Peters, Eduardo & Anguita, Jaime

Abstract:

“We analyze the effect of spatial phase modulation using non-linear functions applied to singular warped beams to control their topological states and intensity distribution. Such beams are candidates for optical trapping and particle manipulation for their controllable pattern of intensities and singularities. We first simulate several kinds of warped beams to analyze their intensity profiles and propagation characteristics. Secondly, we experimentally validate the simulations and investigate the far-field profiles. By calculating the intensity gradients, we describe how these beams are qualified candidates for optical manipulation and trapping.”

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Publication: Photonics
Issue/Year: Photonics, Volume 8; Number 8; Pages 343; 2021
DOI: 10.3390/photonics8080343

Manipulating aqueous droplets by light-induced virtual electrodes

Author(s):

Zamboni, Riccardo; Imbrock, Jörg & Denz, Cornelia

Abstract:

“The precise spatio-temporal manipulation of droplets is fundamental for many lab-on-a-chip systems with applications in biology, healthcare and chemistry. Different approaches have been investigated, including thermal, chemical and electrical methodologies. Among this latter, electrophoresis (EP) and dielectrophoresis (DEP) play a key role, since they are highly compatible with microfluidic systems and provide sufficiently strong forces to control up to microliter volume aqueous droplets. However, EP and DEP techniques typically require the presence of metallic electrodes to create the desired electric fields, making these approaches less flexible and efficient than those exploiting pure optical techniques. Iron-doped lithium niobate (LiNbO3:Fe) allows for the generation of strong electric field modulation due to an inhomogenous illumination, thanks to its photovoltaic properties. These photoinduced fields interact as EP and DEP forces with microdroplets, while guaranteeing the flexibility provided by optical field-based modulation. Indeed, the combination with well-known techniques to control and modulate light fields can be exploited to generate virtual electrodes on the material, achieving reliable as well as flexible devices for water droplets control. In our approach, the photoinduced fields generated by the complex illumination of LiNbO3:Fe are exploited to control motion and trajectory of water droplets inside microfluidic channel. Moreover, the crystal is integrated in standard droplet microfluidic polymeric device, substituting the usual glass substrate and, thus without hindering the portability. This feature combined with the control of positions of aqueous droplets represents a key tool for several applications of customized lab-on-a-chip systems, highlighting the capabilities of LinbO3:Fe-based virtual electrodes.”

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Publication: SPIE Proceedings
Issue/Year: Proc. SPIE 11798, Optical Trapping and Optical Micromanipulation XVIII, 1179824, 2021
DOI: 10.1117/12.2594165

Optically Manipulated Microtools to Measure Adhesion of the Nanoparticle-Targeting Ligand Glutathione to Brain Endothelial Cells

Author(s):

Tamás Fekete, Mária Mészáros, Zsolt Szegletes, Gaszton Vizsnyiczai, László Zimányi, Mária A. Deli, Szilvia Veszelka*, and Lóránd Kelemen

Abstract:

“Targeting nanoparticles as drug delivery platforms is crucial to facilitate their cellular entry. Docking of nanoparticles by targeting ligands on cell membranes is the first step for the initiation of cellular uptake. As a model system, we studied brain microvascular endothelial cells, which form the anatomical basis of the blood–brain barrier, and the tripeptide glutathione, one of the most effective targeting ligands of nanoparticles to cross the blood–brain barrier. To investigate this initial docking step between glutathione and the membrane of living brain endothelial cells, we applied our recently developed innovative optical method. We present a microtool, with a task-specific geometry used as a probe, actuated by multifocus optical tweezers to characterize the adhesion probability and strength of glutathione-coated surfaces to the cell membrane of endothelial cells. The binding probability of the glutathione-coated surface and the adhesion force between the microtool and cell membrane was measured in a novel arrangement: cells were cultured on a vertical polymer wall and the mechanical forces were generated laterally and at the same time, perpendicularly to the plasma membrane. The adhesion force values were also determined with more conventional atomic force microscopy (AFM) measurements using functionalized colloidal probes. The optical trapping-based method was found to be suitable to measure very low adhesion forces (≤ 20 pN) without a high level of noise, which is characteristic for AFM measurements in this range. The holographic optical tweezers-directed functionalized microtools may help characterize the adhesion step of nanoparticles initiating transcytosis and select ligands to target nanoparticles.”

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Publication: ACS Applied Materials & Interfaces
Issue/Year: ACS Applied Materials & Interfaces, Volume 13; Number 33; Pages 39018–39029; 2021
DOI: 10.1021/acsami.1c08454

Optical vortex lattice: an exploitation of orbital angular momentum

Author(s):

Zhu, Liuhao; Tang, Miaomiao; Li, Hehe; Tai, Yuping & Li, Xinzhong

Abstract:

“Generally, an optical vortex lattice (OVL) is generated via the superposition of two specific vortex beams. Thus far, OVL has been successfully employed to trap atoms via the dark cores. The topological charge (TC) on each optical vortex (OV) in the lattice is only ±1. Consequently, the orbital angular momentum (OAM) on the lattice is ignored. To expand the potential applications, it is necessary to rediscover and exploit OAM. Here we propose a novel high-order OVL (HO-OVL) that combines the phase multiplication and the arbitrary mode-controllable techniques. TC on each OV in the lattice is up to 51, which generates sufficient OAM to manipulate microparticles. Thereafter, the entire lattice can be modulated to desirable arbitrary modes. Finally, yeast cells are trapped and rotated by the proposed HO-OVL. To the best of our knowledge, this is the first realization of the complex motion of microparticles via OVL. Thus, this work successfully exploits OAM on OVL, thereby revealing potential applications in particle manipulation and optical tweezers.”

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Publication: Nanophotonics
Issue/Year: Nanophotonics, Volume 10; Number 9; Pages 2487–2496; 2021
DOI: 10.1515/nanoph-2021-0139

Twin curvilinear vortex beams

Author(s):

Wang, Zhuang; Yuan, Zheng; Gao, Yuan; Yan, Wenxiang; Liang, Chunjuan; Ren, Zhi-Cheng; Wang, Xi-Lin; Ding, Jianping & Wang, Hui-Tian

Abstract:

“We report on a novel curvilinear optical vortex beam named twin curvilinear vortex beams (TCVBs) with intensity and phase distribution along a pair of two- or three-dimensional curves, both of which share the same shape and the same topological charge. The TCVBs also possess the character of perfect optical vortex, namely having a size independent of topological charge. We theoretically demonstrate that a TCVB rather than a single-curve vortex beam can be created by the Fourier transform of a cylindrically polarized beam. The behavior of TCVBs generated through our method is investigated by simulation and experiment, including interference experiments for identifying the vortex property of the TCVBs. The TCVBs may find applications in optical tweezers, such as trapping low refractive index particles in the dark region between two curves and driving them moving along the curvilinear trajectory.”

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Publication: Optics Express
Issue/Year: Optics Express, Volume 29; Number 9; Pages 14112; 2021
DOI: 10.1364/oe.423803

Direct axial plane imaging of particle manipulation with nondiffracting Bessel beams

Author(s):

An, Sha; Peng, Tong; Yan, Shaohui; Zhang, Peng; Li, Manman & Yao, Baoli

Abstract:

“Optical manipulation with nondiffracting beams has been attracting great interest and finding widespread applications in many fields such as chemistry, physics, and biomedicine. Generally, optical manipulation is conducted in an optical microscopy system, which, in general, only allows for imaging motions of particles in the transverse plane, rendering the observation of dynamics processes occurring in the axial plane impractical. We propose and demonstrate an optical manipulation system that incorporates an axial plane imaging module. With this system, the trapping behavior in the transverse plane and the transportation process in the axial plane of a particle immersed in a Bessel beam were acquired simultaneously in real time.”

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Publication: Applied Optics
Issue/Year: Applied Optics, Volume 60; Number 11; Pages 2974; 2021
DOI: 10.1364/ao.417854

Flexible rotation of transverse optical field for 2D self-accelerating beams with a designated trajectory

Author(s):

Li, Zongtao; Cao, Kai; Li, Jiasheng; Tang, Yong; Ding, Xinrui & Yu, Binhai

Abstract:

“Self-accelerating beams have the unusual ability to remain diffraction-free while undergo the transverse shift during the free-space propagation. We theoretically identify that the transverse optical field distribution of 2D self-accelerating beam is determined by the selection of the transverse Cartesian coordinates, when the caustic method is utilized for its trajectory design. Based on the coordinate-rotation method, we experimentally demonstrate a scheme to flexibly manipulate the rotation of transverse optical field for 2D self-accelerating beams under the condition of a designated trajectory. With this scheme, the transverse optical field can be rotated within a range of 90 degrees, especially when the trajectory of 2D self-accelerating beams needs to be maintained for free-space photonic interconnection.”

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Publication: Opto-Electronic Advances
Issue/Year: Opto-Electronic Advances, Volume 4; Number 3; Pages 20002101–20002115; 2021
DOI: 10.29026/oea.2021.200021
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