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Based on the annular-core capillary fiber, we propose and demonstrate an optical machine gun that uses photodynamic to achieve directional continuous emission of particles. By grinding the oblique cone at one end of the fiber and soldering it with the single-mode fiber, the liquid containing particles is injected into the air hole while the ring core is illuminated. A 12° cone structure is processed at the other end of the annular-core capillary fiber. The light is reflected by the cone structure to form a cone-shell light field, which realizes the guidance of the particle. The effects of different fluid injection pressures on particle velocity and the relationship between particle velocity and optical power were studied. The experimental results show that under the condition of a certain injection pressure, the greater the output power of the fiber end, the greater the particle velocity; when the output power is constant, the change of liquid injection pressure has little effect on the particle velocity. Finally, when the liquid injection pressure is 40 mbar, the path changes before and after the annular core is illuminated are compared. When the output power of the fiber end is 0 mW, the particle path is divergent. When the output power of the fiber end is 150 mW, the particle path is in linear motion. Due to the unique fiber structure, the proposed fiber device achieves continuous directional continuous emission of particles. It has important value and application prospects in cell manipulation and analysis in microfluidic chip systems and directional drug particle delivery of cells.
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http://dx.doi.org/10.1364/OE.554337 | DOI Listing |
Bioinspir Biomim
September 2025
Mechanical Engineering, University of Massachusetts Dartmouth, 285 Old Westport Road, Dartmouth, Massachusetts, 02747-2300, UNITED STATES.
Harbor seals possess a remarkable ability to detect hydrodynamic footprints left by moving objects, even long after the objects have passed, through interactions between wake flows and their uniquely shaped whiskers. While the flow-induced vibration (FIV) of harbor seal whisker models has been extensively studied, their response to unsteady wakes generated by upstream moving bodies remains poorly understood. This study investigates the wake-induced vibration (WIV) of a flexibly mounted harbor seal-inspired whisker positioned downstream of a forced-oscillating circular cylinder, simulating the hydrodynamic footprint of a moving object.
View Article and Find Full Text PDFJ Sci Food Agric
September 2025
State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, China.
Background: Understanding starch behavior under various processing conditions is important for the development of novel food products with tailored nutritional profiles. This study investigated changes to the structure and properties of native corn starch (NCS) and biomimetic starch-entrapped microspheres following thermal and enzymatic treatments.
Results: Heat-treated microspheres showed more birefringence and structural order than native starch, indicating incomplete gelatinization due to the alginate matrix.
Small
September 2025
Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO, 80303, USA.
Adoptive cell transfers (ACTs) can interact specifically with inflamed tissues, but lack a mechanism for transport through viscous biological barriers such as mucus when administered locally. Further, maintaining cell function is challenging due to the loss of cellular phenotypes in diseased microenvironments. In this work, the use of magnetically controlled helical microrobots is examined to transport macrophages through physiologically representative mucus and maintain functional phenotypes through drug elution for improved cell delivery.
View Article and Find Full Text PDFChaos
September 2025
Institut für Theoretische Physik II - Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany.
We investigate the impact of intermittent energy injections on a Brownian particle, modeled as stochastic renewals of its kinetic energy to a fixed value. Between renewals, the particle follows standard underdamped Langevin dynamics. For energy renewals occurring at a constant rate, we find non-Boltzmannian energy distributions that undergo a shape transition driven by the competition between the velocity relaxation timescale and the renewal timescale.
View Article and Find Full Text PDFJ Chem Phys
September 2025
Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
We numerically examine the dynamics of a probe particle driven at a constant force through an assembly of particles with competing long-range repulsion and short-range attraction that forms a bubble or stripe state. In the bubble regime, we identify several distinct types of motion, including an elastic or pinned regime where the probe particle remains inside a bubble and drags all other bubbles with it. There is also a plastic bubble phase where the bubble in which the probe particle is trapped is able to move past the adjacent bubbles.
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