Article
Optics
Byungjoo Kim, Marjan Ghasemi, Yong Soo Lee, Mingyu Lee, Seokjin Kim, Kyunghwan Oh
Summary: We experimentally demonstrated a tunable microsecond passively Q-switched fiber laser using deionized water as a saturable absorber. The deionized water saturable absorber was integrated into an all-fiber device by filling the gap between two cleaved fiber facets with deionized water, which were enclosed in a glass ferrule. By using a fiber-optic Fabry-Perot interference filter within the cavity, we achieved tunable and robust Q-switching of the fiber laser, avoiding water absorption while maintaining stable operation. The experiment opens up a new avenue of nonlinear aqua-photonics.
JOURNAL OF LUMINESCENCE
(2023)
Article
Optics
Xizhen Xu, Jun He, Jia He, Baijie Xu, Runxiao Chen, Ying Wang, Yatao Yang, Yiping Wang
Summary: SFBGs fabricated using filamentation process exhibit enhanced reflectivity and increased cross-sectional area of refractive index modulations. The fabrication process is efficient and cost-effective, with a production time of only 1.1 seconds. These high-temperature resistant SFBGs can be utilized as quasi-distributed high-temperature sensors, showing great potential in various industries such as metallurgical, chemical, and aviation.
Article
Multidisciplinary Sciences
Ryota Kiya, Tao Tang, Yo Tanaka, Yoichiroh Hosokawa, Yaxiaer Yalikun
Summary: Femtosecond-laser-assisted cell manipulation is a high throughput cell sorting technique that utilizes controlled impulse force for single-step multiple sorting. This paper focuses femtosecond laser pulses within a pocket structure to induce an impulse force on flowing objects. The controllable impulse force allows precise manipulation of objects with various physical qualities. The method is validated in sorting experiments and shows the potential to sort arbitrary subpopulations and develop a single-step multi-selective system.
SCIENTIFIC REPORTS
(2023)
Article
Biochemical Research Methods
Jun ZHang, Christine Rrank, Patrick Byers, Sasa Djordjevic, Denitsa Docheva, Hauke Clausen-Schaumann, Stefanie Sudhop, Heinz P. huber
Summary: In this study, the dynamics of femtosecond laser induced bio-printing with cell-free and cell-laden jets were investigated under varying laser pulse energy and focus depth. The thresholds for the first and second jet were exceeded by increasing the laser pulse energy or decreasing the focus depth, resulting in more laser pulse energy converted to kinetic jet energy. The observed jet forms were quantified using dimensionless hydrodynamic Weber and Rayleigh numbers, and the Rayleigh breakup regime was identified as the preferred process window for single cell bioprinting. The best spatial printing resolution of 42 +/- 3 μm and single cell positioning precision of 12.4 μm were achieved within this window, which is less than one single cell diameter of about 15 μm.
BIOMEDICAL OPTICS EXPRESS
(2023)
Article
Multidisciplinary Sciences
Hong-Yi Lei, Fang-Zheng Sun, Tian-Ze Wang, Hao Chen, Dan Wang, Yan-Yu Wei, Jing-Long Ma, Guo-Qian Liao, Yu-Tong Li
Summary: This research focuses on the highly efficient production of millijoule-level terahertz pulses by irradiating the rear side of a metal foil with a 10-TW femtosecond laser pulse. By analyzing the terahertz and electron emission and conducting particle-in-cell simulations, the physical reasons for the efficient terahertz generation are discussed. The resulting focused terahertz electric field strength exceeding 2 GV/m is experimentally justified.
Article
Chemistry, Physical
Dong Hao, Xiangqian Tang, Yang An, Lihuan Sun, Jianmei Li, Anning Dong, Xinyan Shan, Xinghua Lu
Summary: Through the use of a laser-assisted scanning tunneling microscope, the orientation switching of individual azobenzene molecules on a Au(111) surface was investigated. It was found that rotational motion of the molecule can be controlled by both sample bias and laser wavelength, with thresholds in bias voltage and minimal photon energy derived. The study revealed the significant contribution of tip-induced local electrostatic potential to reducing the hopping barrier, and identified distinct roles played by tunneling electrons and photons in controlling the rotational dynamics of single azobenzene molecules.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Optics
Ajanta Barh, Alexander Nussbaum-Lapping, Jonas Heidrich, Marco Gaulke, Matthias Golling, Christopher R. Phillips, Ursula Keller
Summary: We have developed a dual-modelocked femtosecond oscillator that operates at wavelengths beyond 2 pm. This laser utilizes a Cr:ZnS gain medium, an InGaSb SESAM for modelocking, and a reflective device for spatial duplexing of the pulse trains. The laser achieves a FWHM spectral bandwidth of 30 nm, average power over 200 mW, and pulse duration close to 200 fs at a wavelength of 2.36 pm. The stable modelocked pulses can be produced over a wide range of output powers, making it suitable for dual-comb applications above 2 pm.
Article
Optics
H. T. Olgun, W. Tian, G. Cirmi, K. Ravi, C. Rentschler, H. Cankaya, M. Pergament, M. Hemmer, Y. Hua, D. N. Schimpf, N. H. Matlis, F. X. Kaertner
Summary: In this study, a novel laser source was used to achieve efficient conversion of light to terahertz (THz) radiation, with a record efficiency of 0.9%. The generation of THz radiation in magnesium-doped periodically poled lithium niobate (PPLN) crystals was explored under different conditions. This work addresses the problem of low optical-to-THz radiation conversion efficiencies, which has limited the demand for high-field THz radiation pulses.
Article
Multidisciplinary Sciences
Vojtech Horny, Sophia N. Chen, Xavier Davoine, Vincent Lelasseux, Laurent Gremillet, Julien Fuchs
Summary: By utilizing numerical simulations, this study explores strategies to optimize neutron sources from ion-induced nuclear reactions. It is found that using ultrathin solid foils as targets, along with near-critical density plasma layers, can enhance ion acceleration and increase neutron yield. These findings have significant implications for experimental studies.
SCIENTIFIC REPORTS
(2022)
Article
Optics
Kevin M. Dorney, Tingting Fan, Quynh L. D. Nguyen, Jennifer L. Ellis, Daniel D. Hickstein, Nathan Brooks, Dmitriy Zusin, Christian Gentry, Carlos Hernandez-Garcia, Henry C. Kapteyn, Margaret M. Murnane
Summary: The study extends the photon energy range of circularly polarized high-harmonics and generates single-helicity HHG spectra using counter-rotating femtosecond laser pulses. Circularly polarized soft x-ray harmonics beyond 170 eV are produced in helium, while dense spectra at high photon energies are generated in an argon medium, consistent with the generation of circularly polarized attosecond pulses. Theoretically, it is shown that circularly polarized HHG photon energies can extend beyond the carbon K edge, broadening the range of accessible molecular and materials systems for dynamic HHG chiral spectro-microscopies.
Article
Multidisciplinary Sciences
Enrico Brunetti, R. Neil Campbell, Jack Lovell, Dino A. Jaroszynski
Summary: A numerical study shows that CO2 lasers with a wavelength of 10.6μm and peak powers of 100-800TW can produce high-charge electron beams, surpassing the capabilities of femtosecond near-infrared laser driven laser-wakefield accelerators (LWFAs) by up to three orders of magnitude. These CO2 laser driven LWFAs can generate electron beams with energies ranging from tens of MeV to GeV and charges from 1-100nC in plasma or gas media without requiring external guiding.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Evelina I. Nikelshparg, Ekaterina S. Prikhozhdenko, Roman A. Verkhovskii, Vsevolod S. Atkin, Vitaly A. Khanadeev, Boris N. Khlebtsov, Daniil N. Bratashov
Summary: A new type of flat substrate utilizing stabilized aggregates of gold nanostars and a polymer layer has been used for visualizing structures and studying biochemical processes within living cells via surface-enhanced Raman scattering (SERS). The long tips of the gold nanostars can penetrate the cell membrane to receive the SERS signal from biomolecules inside the cell, aiding in the study of biomolecular distribution in different cell compartments.
Article
Optics
Qianni Li, Xinrong Xu, Yanbo Wu, Yan Yin, Debin Zou, Tongpu Yu
Summary: By mixing two circularly polarized lasers with different frequencies, stronger harmonics and shorter attosecond pulses can be generated in overdense plasma.
Article
Optics
Xue Zhou, Jiatong Li, Jiajia Mao, Ping Hu, Hongkun Nie, Huahang Wang, Ruihua Wang, Tao Li, Baitao Zhang, Jingliang He, Kejian Yang
Summary: A diode-pumped passively mode-locked Tm3+-doped YLF bulk laser operating at around 2.3 μm is achieved successfully using a GaAs-based SESAM. Stable ultrashort pulses with a duration of 52.5 ps and a repetition rate of 67 MHz are generated in the continuous mode-locking regime, with a maximum dual-output power of 284 mW. The radio-frequency spectrum of the output pulses demonstrates a high signal-to-noise ratio of 60 dB. This is the first report of a diode-pumped all-solid-state passively mode-locked thulium-doped laser operating at around 2.3 μm.
Article
Optics
J. Molinuevo, E. Rodriguez-Vidal, I Quintana, M. Morales, C. Molpeceres
Summary: This study investigated the use of ultrashort laser pulses on Polypropylene and found that using bursts of pulses improves quality and removal rates.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Zemin Liu, Meng Li, Xiaoguang Dong, Ziyu Ren, Wenqi Hu, Metin Sitti
Summary: The authors propose a molding-integrated direct laser writing fabrication protocol to create 3D micron-scale devices with programmable magnetization and multi-material integration. This method enables diverse motions and functionalities, showcasing its versatility in various fields such as healthcare, robotics, metamaterials, microfluidics, and programmable matter.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Mingtong Li, Yichao Tang, Ren Hao Soon, Bin Dong, Wenqi Hu, Metin Sitti
Summary: Wireless small-scale soft actuators, utilizing the interactions between coiled artificial muscle and radio frequency-magnetic heating, have been developed to address the constraints of current miniature soft actuators. These wirelessly controlled actuators exhibit a large output force and high work capacity, and can be designed into various functional devices for minimally invasive medical applications.
Article
Chemistry, Multidisciplinary
Yichao Tang, Mingtong Li, Tianlu Wang, Xiaoguang Dong, Wenqi Hu, Metin Sitti
Summary: The article introduces a miniature magnetic phase-change soft composite actuator with large output force and work capacity, which can be used in potential applications in medical and robotic fields. Experiments demonstrate that the actuator performs well under remote magnetic radio frequency heating, showing its promising prospects for diverse applications.
ADVANCED MATERIALS
(2022)
Article
Multidisciplinary Sciences
Ren Hao Soon, Ziyu Ren, Wenqi Hu, Ugur Bozuyuk, Erdost Yildiz, Meng Li, Metin Sitti
Summary: This article presents a wireless spring-preloaded barbed needle release mechanism for anchoring untethered soft miniature robots. The mechanism is wirelessly triggered using radio-frequency remote heating and can be easily integrated into existing robotic platforms. It provides robust anchoring in biological tissues and extends the operating depth of the device inside the body. This mechanism opens up new possibilities for biomedical functionalities in untethered soft medical robots.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Multidisciplinary Sciences
Tianlu Wang, Halim Ugurlu, Yingbo Yan, Mingtong Li, Meng Li, Anna-Maria Wild, Erdost Yildiz, Martina Schneider, Devin Sheehan, Wenqi Hu, Metin Sitti
Summary: A wireless stent-shaped magnetic soft robot is proposed for performing endovascular operations. The robot demonstrates shape-adaptive locomotion capabilities in complex arterial environments and can be used for various medical functions, making it a powerful tool for new distal endovascular operations.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Jiachen Zhang, Ren Hao Soon, Zihan Wei, Wenqi Hu, Metin Sitti
Summary: Miniature untethered robots have gained increasing interest, with soft robots exhibiting compliance, versatility, and agility. This study reports a liquid metal-elastomer composite that uses dual energy transmission modes (ETM) of magnetic field and radio-frequency induction to enable shape-morphing and provide power and excess heat for multifunctional miniature robots.
Article
Multidisciplinary Sciences
Ziyu Ren, Mingchao Zhang, Shanyuan Song, Zemin Liu, Chong Hong, Tianlu Wang, Xiaoguang Dong, Wenqi Hu, Metin Sitti
Summary: In this study, we propose an electrically driven soft-robotic ciliated epidermis with multiple independently controlled polypyrrole bending actuators. The beating kinematics and coordination of multiple actuators can be reconfigured to control fluid transportation, enabling fluid manipulation on various surfaces.
Article
Energy & Fuels
Ci Ao, Suying Yan, Sitong Zhao, Wenqi Hu, Long Zhao, Yuting Wu
Summary: In this study, SA/EG composite phase change material was prepared by incorporating EG into melted SA. The addition of EG significantly improved the thermal conductivity, melting enthalpy, and melting temperature of the composite material. Furthermore, the composite PCM exhibited enhanced heat storage and release rates, as well as excellent thermal stability, chemical stability, and cyclic stability.
Article
Chemistry, Multidisciplinary
Jianfeng Yang, Hang Zhang, Alex Berdin, Wenqi Hu, Hao Zeng
Summary: The rise of stimuli-responsive polymers has greatly expanded the materials available for small-scale, wirelessly controlled soft-bodied robots. Inspired by the dandelion seed, researchers have designed an artificial seed with a soft actuator made of light-responsive liquid crystalline elastomer. This artificial seed demonstrates optically controlled wind-assisted dispersal and lift-off/landing actions, as well as light-induced local accumulation in descending structures. These findings provide novel approaches for wirelessly controlled, miniature devices that can navigate over a large aerial space.
Article
Multidisciplinary Sciences
Tianlu Wang, Hyeong-Joon Joo, Shanyuan Song, Wenqi Hu, Christoph Keplinger, Metin Sitti
Summary: Researchers have developed a jellyfish-like robotic platform that enables noise-free and gentle interactions with underwater species. The platform has various functions, including fluid flow control, object manipulation, shape adaptation, navigation, wireless swimming, and cooperation of multiple robots. This study introduces a versatile jellyfish-like robotic platform for diverse applications.
Article
Biochemical Research Methods
Wenqi Hu, Yidan Zhu, Qu Tang, Xiaolei Ji, Lei Wang, Weijun Ou, Guo Li, Li Wu, Hui Cong, Yuling Qin
Summary: This study presents a simple digital microfluidic chip driven by centrifugal force for digital PCR analysis. Regardless of the surface properties, an efficient digitization process can be achieved. The chip design allows for the quantification of nucleic acids and has the potential for multi-target detection.
BIOTECHNOLOGY JOURNAL
(2023)
Article
Multidisciplinary Sciences
Dan Wang, Zhaomin Chen, Mingtong Li, Zhen Hou, Changsong Zhan, Qijun Zheng, Dalei Wang, Xin Wang, Mengjiao Cheng, Wenqi Hu, Bin Dong, Feng Shi, Metin Sitti
Summary: The authors report a rotary flying photoactuator with fast rotation and rapid response, which is achieved through the synergistic interactions between photothermal graphene and hygroscopic agar/silk fibroin components. This photoactuator exhibits ultrafast rotation and rapid response, making it suitable for applications in soft robotics and miniature devices.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Yingbo Yan, Tianlu Wang, Rongjing Zhang, Yilun Liu, Wenqi Hu, Metin Sitti
Summary: Methodologies based on intravascular imaging have revolutionized the diagnosis and treatment of endovascular diseases. However, current methods are limited in detecting complicated occluded vessels. Therefore, a miniature soft tool has been proposed to visualize and cross occlusions with various morphologies, which could enhance the efficacy of minimally invasive medicine for the diagnosis and treatment of occlusions in various circulatory systems.
Article
Automation & Control Systems
Wenkang Wang, Shanyuan Song, Wenqi Hu
Summary: This study investigates artificial cilia that can both actuate and sense, inspired by natural motile cilia. These artificial cilia can independently sense flow speed and collaboratively transport objects, and also sense fluid viscosity and distance from the wall by feeling their own motion. Two sensing modes are proposed and studied for low and high Reynolds numbers. The results show that mode 1 can sense a wall distance up to 3 times the body length of the cilium, while mode 2 can sense up to 2 times. This work has applications in small-scale soft robots working inside fluid and flow control.
ADVANCED INTELLIGENT SYSTEMS
(2023)
Article
Chemistry, Multidisciplinary
Wenqi Hu, Mohammad A. Kher-Elden, Hexu Zhang, Peng Cheng, Lan Chen, Ignacio Piquero-Zulaica, Zakaria M. Abd El-Fattah, Johannes V. Barth, Kehui Wu, Yi-Qi Zhang
Summary: In this study, the tailoring of Shockley surface-state electrons using complex interfacial supramolecular tessellations was investigated. Experimental and modeling results showed the possibility of realizing novel two-dimensional electronic structures through quantum dot coupling, which could provide a complementary and versatile route for controlling surface electronic landscapes.
