Optofluidics is a rising technology that combines microfluidics and optics.Its goal is to manipulate light and flowing liquids on the micro/nanoscale and exploiting their interaction in optofluidic chips.The fluid flo...Optofluidics is a rising technology that combines microfluidics and optics.Its goal is to manipulate light and flowing liquids on the micro/nanoscale and exploiting their interaction in optofluidic chips.The fluid flow in the on-chip devices is reconfigurable,non-uniform and usually transports substances being analyzed,offering a new idea in the accurate manipulation of lights and biochemical samples.In this paper,we summarized the light modulation in heterogeneous media by unique fluid dynamic properties such as molecular diffusion,heat conduction,centrifugation effect,light-matter interaction and others.By understanding the novel phenomena due to the interaction of light and flowing liquids,quantities of tunable and reconfigurable optofluidic devices such as waveguides,lenses,and lasers are introduced.Those novel applications bring us firm conviction that optofluidics would provide better solutions to high-efficient and high-quality lab-on-chip systems in terms of biochemical analysis and environment monitoring.展开更多
Digital enzyme-linked immunoassays(dELISA)have been successfully applied to the ultrasensitive quantification of analytes,including nucleic acids,proteins,cells,and extracellular vesicles,achieving robust detection li...Digital enzyme-linked immunoassays(dELISA)have been successfully applied to the ultrasensitive quantification of analytes,including nucleic acids,proteins,cells,and extracellular vesicles,achieving robust detection limits in complex clinical specimens such as blood,and demonstrating utility across a broad range of clinical applications.The ultrasensitivity of dELISA comes from partitioning single analytes,captured onto a microbead,into millions of compartments so that they can be counted individually.There is particular interest in using dELISA for multiplexed measurements,but generating and detecting the billions of compartments necessary to perform multiplexed ultrasensitive dELISA remains a challenge.To address this,we have developed a high-throughput,optofluidic platform that performs quantitative fluorescence measurements on five populations of microbeads,each encoded with distinct ratios of two fluorescent dyes,for digital assays.The key innovation of our work is the parallelization of droplet generation and detection,combined with time-domain encoding of the excitation sources into distinct patterns that barcode the emission signal of both dyes within each bead,achieving high throughput(6×10^(6) droplets/min)and accurate readout.Additionally,we modulate the exposure settings of the digital camera,capturing images of multiplexed beads and the droplet fluorescent substrate in consecutive frames,a method inspired by high dynamic range(HDR)photography.Our platform accurately classifies five populations of dual-encoded beads(accuracy>99%)and detects bead-bound streptavidin-horseradish peroxidase molecules in a third fluorescence channel.This work establishes the technological foundation to combine high multiplexing and high throughput for droplet digital assays.展开更多
Bio-imaging generally indicates imaging techniques that acquire biological information from living forms.Recently, the ability to detect, diagnose, and monitor pathological, physiological, and molecular dynamics is in...Bio-imaging generally indicates imaging techniques that acquire biological information from living forms.Recently, the ability to detect, diagnose, and monitor pathological, physiological, and molecular dynamics is in great demand, while scaling down the observing angle, achieving precise alignment, fast actuation, and a miniaturized platform become key elements in next-generation optical imaging systems. Optofluidics, nominally merging optic and microfluidic technologies, is a relatively new research field, and it has drawn great attention since the last decade. Given its abilities to manipulate both optic and fluidic functions/elements in the micro-/nanometer regime, optofluidics shows great potential in bio-imaging to elevate our cognition in the subcellular and/or molecular level. In this paper, we emphasize the development of optofluidics in bio-imaging, from individual components to representative applications in a more modularized, systematic sense. Further, we expound our expectations for the near future of the optofluidic imaging discipline.展开更多
In this study,we developed a single-beam optical trap-based surface-enhanced Raman scattering(SERS)optofluidic molecular fingerprint spectroscopy detection system.This system utilizes a single-beam optical trap to con...In this study,we developed a single-beam optical trap-based surface-enhanced Raman scattering(SERS)optofluidic molecular fingerprint spectroscopy detection system.This system utilizes a single-beam optical trap to concentrate free silver nanoparticles(AgNPs)within an optofluidic chip,significantly enhancing SERS performance.We investigated the optical field distribution characteristics within the tapered fiber using COMSOL simulation software and established a MATLAB simulation model to validate the single-beam optical trap's effectiveness in capturing AgNPs,demonstrating the theoretical feasibility of our approach.To verify the particle capture efficacy of the system,we experimentally controlled the optical trap's on-off state to manage the capture and release of particles precisely.The experimental results indicated that the Raman signal intensity in the capture state was significantly higher than in the non-capture state,confirming that the single-beam optical trap effectively enhances the SERS detection capability of the optofluidic detection system.Furthermore,we employed Raman mapping techniques to investigate the impact of the capture area on the SERS effect,revealing that the spectral intensity of molecular fingerprints in the laser-trapping region is significantly improved.We successfully detected the Raman spectrum of crystal violet at a concentration of 10^(−9)mol/L and pesticide thiram at a concentration of 10^(−5)mol/L,further demonstrating the ability of the single-beam optical trap in enhancing the molecular fingerprint spectrum identification capability of the SERS optofluidic chips.The optical trapping SERS optofluidic detection system developed in this study,as a key component of an integrated optoelectronic sensing system,holds the potential for integration with portable high-power lasers and high-performance Raman spectrometers.This integration is expected to advance highly integrated technologies and significantly enhance the overall performance and portability of optoelectronic sensing systems.展开更多
Based on optofluidics and whispering gallery mode(WGM)theory,here an optofluidic refractive index sensor with microtube-coupled suspended core fiber(SCF)is proposed.It solves the issues of general sensors with microca...Based on optofluidics and whispering gallery mode(WGM)theory,here an optofluidic refractive index sensor with microtube-coupled suspended core fiber(SCF)is proposed.It solves the issues of general sensors with microcavity-coupled fiber taper such as too fragile,unstable performance due to open coupling,poor portability and repeatability,while overcoming the poor performance of low refractive index sensing in general full-package fiber sensors.The sensor only needs a very small amount of liquid sample(about 1.8 nL).The proposed sensor combines the excellent performance of full package,optofluidics and WGM resonator.The resonant characteristics and sensing performance of the sensor are analyzed and discussed by the theoretical simulation.The simulation results indicate that the sensor has a wide refractive index sensing range(1.330-1.700)and good performance.The resonance wavelength shift has a good linear relationship with the liquid refractive index variation.In the low refractive index region,the sensitivity is 222.5-247.5 nm/RIU,Q-factor is 1.03×10^(3) and the detection limit is 3.64×10^(-4) RIU.In the medium and high refractive index regions,the sensitivity is 564.4-846.2 nm/RIU,Q-factor is up to 8.62×10^(4),and the detection limit can be as low as 1.29×10^(-6) RIU.The sensor exhibits a high sensitivity,a high Q-factor and a very low detection limit.展开更多
A tunable plasmofluidic lens consisting of nanoslit arrays on a metal film is proposed for subwavelength imaging in far field at different wavelengths.The nanoslit arrays with constant depths but varying widths could ...A tunable plasmofluidic lens consisting of nanoslit arrays on a metal film is proposed for subwavelength imaging in far field at different wavelengths.The nanoslit arrays with constant depths but varying widths could generate desired optical phase retardations based on the propagation property of the surface plasmon polaritons(SPPs)through the metal-dielectric-metal(MDM)nanoslit waveguide.We demonstrate the tunability of the plasmofluidic lens for subwavelength imaging by changing the surrounding dielectric fluid.This work provides a novel approach for developing integrative tunable plasmofluidic lens for a variety of lab-on-chip applications.展开更多
Optical axial scanning is essential process to obtain 3D information of biological specimens. To realize optical axial scanning without moving, the tunable lens is a solution. However, the conventional tunable lenses ...Optical axial scanning is essential process to obtain 3D information of biological specimens. To realize optical axial scanning without moving, the tunable lens is a solution. However, the conventional tunable lenses usually induce non-uniform magnification and resolution issues. In this paper, we report a movable electrowetting optofluidic lens. Unlike the conventional tunable lens, our proposed optofluidic lens has two liquid-liquid (L-L) interfaces, which can move in the cell by an external voltage. The object distance and image distance are adjusted by shifting the L-L interface position. Therefore, the proposed lens can realize optical axial scanning with uniform magnification and resolution in microscopy. To prove the concept, we fabricate an optofluidic lens and use it in optical axial scanning. The scanning distance is more than 1 mm with uniform magnification and good imaging quality. Widespread application of such a new adaptive zoom lens is foreseeable.展开更多
Bending optofluidic waveguides are essential for developing high-performance fluid-based photonic circuits and systems.The combination of femtosecond(fs)-laser-assisted etching of high-precision microchannels and vacu...Bending optofluidic waveguides are essential for developing high-performance fluid-based photonic circuits and systems.The combination of femtosecond(fs)-laser-assisted etching of high-precision microchannels and vacuum-assisted liquid-core filling allows the controllable fabrication of low-loss optofluidic waveguides in fused silica.展开更多
Optical fiber sensors have gained significant attention in recent years owing to their remarkable advantages of remote operation and rapid response.The integration of optical fiber sensing with the microfluidics techn...Optical fiber sensors have gained significant attention in recent years owing to their remarkable advantages of remote operation and rapid response.The integration of optical fiber sensing with the microfluidics technology has paved the way for the establishment of optical fiber optofluidic sensing.Optical fiber optofluidic systems possess the advantages of the low invasiveness,compact structure,excellent biocompatibility,and the ability to handle small analyte volumes,rendering them particularly suitable for serving as chemical sensors and biosensors.In this paper,we present an in-depth overview of optical fiber optofluidic chemical sensors and biosensors.Firstly,we provide a comprehensive summary of the types of optical fibers commonly employed in optofluidic chemical and biosensing,elucidating their distinct attributes and performance characteristics.Subsequently,we introduce and thoroughly analyze several representative sensing mechanisms employed in optical fiber optofluidic systems and main performance parameters.Furthermore,this review delves into the modification and functionalization of optical fibers.Additionally,we showcase typical biosensing and chemical sensing applications to demonstrate the practicality and versatility of optical fiber optofluidic sensing.Finally,the conclusion and outlook are given.展开更多
Infectious diseases such as coronavirus disease 2019(COVID-19)continue to pose significant global health challenges.Effective management of reinfection risks depends on sustained levels of binding and neutralizing ant...Infectious diseases such as coronavirus disease 2019(COVID-19)continue to pose significant global health challenges.Effective management of reinfection risks depends on sustained levels of binding and neutralizing antibodies.However,conventional methods—such as enzyme-linked immunosorbent assays(ELISA)and virus neutralization tests(VNT)—are limited by complex workflows,long assay durations,and high sample volume requirements,making them less suit-able for routine,decentralized,or time-sensitive surveillance.This study presents a custom-developed tip optofluidic immunoassay(TOI)platform that enables rapid,multiplexed antibody profiling using only 1 mL offingertip blood.The system integrates batch-fabricated microfluidic immunoreactors with a portable chemiluminescent imaging station,completing both binding and neutralization capability assessments within 40 min.TOI achieves a broad dynamic range(3–4 orders of magnitude),high signal-to-noise ratio(10,000),and excellent sensitivity for immunoglobulin G(IgG)detection.A renovated version of the rapid in vitro inhibition assay(RIVIA)is incorporated to evaluate neutralizing an-tibodies against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)with greater speed and cost-effi-ciency.In clinical studies,TOI successfully quantified antibody protection against multiple variants,identifying individ-uals with broad-spectrum immunity to both wild-type and XBB strains.With its high-precision,rapid turnaround,and minimal sample requirement,TOI offers a valuable tool for decentralized immune surveillance and personalized immu-nization strategy development.展开更多
Developing a portable yet affordable method for the discrimination of chemical substances with good sensitivity and selectivity is essential for on-site visual detection of unknown substances.Herein,we propose an opto...Developing a portable yet affordable method for the discrimination of chemical substances with good sensitivity and selectivity is essential for on-site visual detection of unknown substances.Herein,we propose an optofluidic paper-based analytical device(PAD)that consists of a macromolecule-driven flow(MDF)gate and photonic crystal(PhC)coding units,enabling portable and scalable detection and discrimination of various organic chemical,mimicking the olfactory system.The MDF gate is designed for precise flow control of liquid analytes,which depends on intermolecular interactions between the polymer at the MDF gate and the liquid analytes.Subsequently,the PhC coding unit allows for visualizing the result obtained from the MDF gate and generating differential optical patterns.We fabricate an optofluidic PAD by integrating two coding units into a three-dimensional(3D)microfluidic paper within a 3D-printed cartridge.The optofluidic PADs clearly distinguish 11 organic chemicals with digital readout of pattern recognition from colorimetric signals.We believe that our optofluidic coding strategy mimicking the olfactory system opens up a wide range of potential applications in colorimetric monitoring of chemicals observed in environment.展开更多
We have developed a self-contained,liquid tunable microlens based on polyacrylate membranes integrated with compact on-chip thermo-pneumatic actuation fabricated using full-wafer processing.Silicone oil is used as the...We have developed a self-contained,liquid tunable microlens based on polyacrylate membranes integrated with compact on-chip thermo-pneumatic actuation fabricated using full-wafer processing.Silicone oil is used as the optical liquid,which is pushed or pulled into the lens cavity via an extended microfluidic channel structure without any pumps,valves or other mechanical means.The heat load generated by the thermal actuator is physically isolated from the lens chamber.The back focal length may be tuned from infinity to 4 mm with a maximum power consumption of 300 mW.The principal application is fine tuning of the back focal length,for which tuning time constants as small as 100 ms are suitable.展开更多
Understanding light–matter interaction lies at the core of our ability to harness physical effects and to translate them into new capabilities realized in modern integrated photonics platforms.Here,we present the des...Understanding light–matter interaction lies at the core of our ability to harness physical effects and to translate them into new capabilities realized in modern integrated photonics platforms.Here,we present the design and characterization of optofluidic components in an integrated photonics platform and computationally predict a series of physical effects that rely on thermocapillary-driven interaction between waveguide modes and topography changes of optically thin liquid dielectric film.Our results indicate that this coupling introduces substantial self-induced phase change and transmittance change in a single channel waveguide,transmittance through the Bragg grating waveguide,and nonlocal interaction between adjacent waveguides.We then employ the self-induced effects together with the inherent built-in finite relaxation time of the liquid film,to demonstrate that the light-driven deformation can serve as a reservoir computer capable of performing digital and analog tasks,where the gas–liquid interface operates both as a nonlinear actuator and as an optical memory element.展开更多
The use of optical tweezers to measure forces acting upon microscopic particles has revolutionised fields from material science to cell biology.However,despite optical control capabilities,this technology is highly co...The use of optical tweezers to measure forces acting upon microscopic particles has revolutionised fields from material science to cell biology.However,despite optical control capabilities,this technology is highly constrained by the material properties of the probe,and its use may be limited due to concerns about the effect on biological processes.Here we present a novel,optically controlled trapping method based on light-induced hydrodynamic flows.Specifically,we leverage optical control capabilities to convert a translationally invariant topological defect of a flow field into an attractor for colloids in an effectively one-dimensional harmonic,yet freely rotatable system.Circumventing the need to stabilise particle dynamics along an unstable axis,this novel trap closely resembles the isotropic dynamics of optical tweezers.Using magnetic beads,we explicitly show the existence of a linear force-extension relationship that can be used to detect femtoNewton-range forces with sensitivity close to the thermal limit.Our force measurements remove the need for laser-particle contact,while also lifting material constraints,which renders them a particu-larly interesting tool for the life sciences and engineering.展开更多
Optical metamaterials and metasurfaces,which emerged in the course of the last few decades,have revolutionized our understanding of light and light–matter interaction.While solid materials are naturally employed as k...Optical metamaterials and metasurfaces,which emerged in the course of the last few decades,have revolutionized our understanding of light and light–matter interaction.While solid materials are naturally employed as key building elements for construction of optical metamaterials mainly due to their structural stability,practically no attention was given to study of liquid-made optical two-dimensional(2-D)metasurfaces and the underlying interaction regimes between surface optical modes and liquids.We theoretically demonstrate that surface plasmon polaritons and slab waveguide modes that propagate within a thin liquid dielectric film trigger optical self-induced interaction facilitated by surface tension effects,which leads to the formation of 2-D optical liquid-made lattices/metasurfaces with tunable symmetry and can be leveraged for tuning of lasing modes.Furthermore,we show that the symmetry breaking of the 2-D optical liquid lattice leads to phase transition and tuning of its topological properties,which allows the formation,destruction,and movement of Dirac-points in the k-space.Our results indicate that optical liquid lattices support extremely low lasing threshold relative to solid dielectric films and have the potential to serve as configurable analogous computation platform.展开更多
We demonstrate a tunable imaging system based on the functionality of the mammalian eye using soft-matter micro-optical components.Inspired by the structure of the eye,as well as by the means through which nature tune...We demonstrate a tunable imaging system based on the functionality of the mammalian eye using soft-matter micro-optical components.Inspired by the structure of the eye,as well as by the means through which nature tunes its optical behavior,we show that the technologies of microsystems engineering and micro-optics may be used to realize a technical imaging system whose biomimetic functionality is entirely distinct from that of conventional optics.The engineered eyeball integrates a deformable elastomeric refractive structure whose shape is mechanically controlled through application of strain using liquid crystal elastomer(LCE)actuators;two forms of tunable iris,one based on optofluidics and the other on LCEs with embedded heaters;a fixed lens arrangement;and a commercial imaging sensor chip.The complete microsystem,optimized to yield optical characteristics close to those of the human eye,represents the first fully functional,soft-matter-based tunable single-aperture eye-like imager.展开更多
The shape of liquid interfaces can be precisely controlled using electrowetting,an actuation mechanism which has been widely used for tunable optofluidic micro-optical components such as lenses or irises.We have expan...The shape of liquid interfaces can be precisely controlled using electrowetting,an actuation mechanism which has been widely used for tunable optofluidic micro-optical components such as lenses or irises.We have expanded the considerable flexibility inherent in electrowetting actuation to realize a variable optofluidic slit,a tunable and reconfigurable two-dimensional aperture with no mechanically moving parts.This optofluidic slit is formed by precisely controlled movement of the liquid interfaces of two highly opaque ink droplets.The 1.5mmlong slit aperture,with controllably variable discrete widths down to 45 mm,may be scanned across a length of 1.5mmwith switching times between adjacent slit positions of less than 120 ms.In addition,for a fixed slit aperture position,the width may be tuned to a minimum of 3 mmwith high uniformity and linearity over the entire slit length.This compact,purely fluidic device offers an electrically controlled aperture tuning range not achievable with extant mechanical alternatives of a similar size.展开更多
We discuss the implementation and performance of an adaptive optics(AO)system that uses two cascaded deformable phase plates(DPPs),which are transparent optofluidic phase modulators,mimicking the common woofer/tweeter...We discuss the implementation and performance of an adaptive optics(AO)system that uses two cascaded deformable phase plates(DPPs),which are transparent optofluidic phase modulators,mimicking the common woofer/tweeter-type astronomical AO systems.One of the DPPs has 25 electrodes forming a keystone pattern best suited for the correction of low-order and radially symmetric modes;the second device has 37 hexagonally packed electrodes better suited for high-order correction.We also present simulation results and experimental validation for a new open-loop control strategy enabling simultaneous control of both DPPs,which ensures optimum correction for both large-amplitude low-order,and complex combinations of low-and high-order aberrations.The resulting system can reproduce Zernike modes up to the sixth radial order with stroke and fidelity up to twice better than what is attainable with either of the DPPs individually.The performance of the new AO configuration is also verified in a custom-developed fluorescence microscope with sensorless aberration correction.展开更多
The high-precision integration of three-dimensional(3D)microoptical components into microfluidics in a customizable manner is crucial for optical sensing,fluorescence analysis,and cell detection in optofluidic applica...The high-precision integration of three-dimensional(3D)microoptical components into microfluidics in a customizable manner is crucial for optical sensing,fluorescence analysis,and cell detection in optofluidic applications;however,it remains challenging for current microfabrication technologies.This paper reports the in-channel integration of flexible two-dimensional(2D)and 3D polymer microoptical devices into glass microfluidics by developing a novel technique:flat scaffold-supported hybrid femtosecond laser microfabrication(FSS-HFLM).The scaffold with an optimal thickness of 1–5 μm is fabricated on the lower internal surface of a microfluidic channel to improve the integration of high-precision microoptical devices on the scaffold by eliminating any undulated internal channel surface caused by wet etching.As a proof of demonstration,two types of typical microoptical devices,namely,2D Fresnel zone plates(FZPs)and 3D refractive microlens arrays(MLAs),are integrated.These devices exhibit multicolor focal spots,elongated(>three times)focal length and imaging of the characters‘RIKEN’in a liquid channel.The resulting optofluidic chips are further used for coupling-free white-light cell counting with a success rate as high as 93%.An optofluidic system with two MLAs and a W-filter is also designed and fabricated for more advanced cell filtering/counting applications.展开更多
The ultrafast monitoring of deoxyribonucleic acid(DNA)dynamic structural changes is an emerging and rapidly growing research topic in biotechnology.The existing optical spectroscopy used to identify different dynamica...The ultrafast monitoring of deoxyribonucleic acid(DNA)dynamic structural changes is an emerging and rapidly growing research topic in biotechnology.The existing optical spectroscopy used to identify different dynamical DNA structures lacks quick response while requiring large consumption of samples and bulky instrumental facilities.It is highly demanded to develop an ultrafast technique that monitors DNA structural changes with the external stimulus or cancer-related disease scenarios.Here,we demonstrate a novel photonic integrated graphene-optofluidic device to monitor DNA structural changes with the ultrafast response time.Our approach is featured with an effective and straightforward design of decoding the electronic structure change of graphene induced by its interactions with DNAs in different conformations using ultrafast nanosecond pulse laser and achieving refractive index sensitivity of~3×10^(−5) RIU.This innovative technique for the first time allows us to perform ultrafast monitoring of the conformational changes of special DNA molecules structures,including G-quadruplex formation by K+ions and i-motif formation by the low pH stimulus.The graphene-optofluidic device as presented here provides a new class of label-free,ultrafast,ultrasensitive,compact,and cost-effective optical biosensors for medical and healthcare applications.展开更多
基金This work is financially supported by National Natural Science Foundation of China(No.11774274)National Key R&D Program of China(2018YFC1003200)+1 种基金Open Financial Grant from Qingdao National Laboratory for Marine Science and Technology(No.QNLM2016ORP0410)Foundation Research Fund of Shenzhen Science and Technology Program(No.JCYJ20170818112939064).
文摘Optofluidics is a rising technology that combines microfluidics and optics.Its goal is to manipulate light and flowing liquids on the micro/nanoscale and exploiting their interaction in optofluidic chips.The fluid flow in the on-chip devices is reconfigurable,non-uniform and usually transports substances being analyzed,offering a new idea in the accurate manipulation of lights and biochemical samples.In this paper,we summarized the light modulation in heterogeneous media by unique fluid dynamic properties such as molecular diffusion,heat conduction,centrifugation effect,light-matter interaction and others.By understanding the novel phenomena due to the interaction of light and flowing liquids,quantities of tunable and reconfigurable optofluidic devices such as waveguides,lenses,and lasers are introduced.Those novel applications bring us firm conviction that optofluidics would provide better solutions to high-efficient and high-quality lab-on-chip systems in terms of biochemical analysis and environment monitoring.
基金funding from the following sources:National Human Genome Research Institute(RM1-HG-010023)National Cancer Institute(R21CA236653,R33CA278551)+2 种基金National Institute of Mental Health(R33-NIMH-118170)National Institute of Allergy and Infectious Diseases(R33-AI-147406)National Defense Science and Engineering Graduate Fellowship.
文摘Digital enzyme-linked immunoassays(dELISA)have been successfully applied to the ultrasensitive quantification of analytes,including nucleic acids,proteins,cells,and extracellular vesicles,achieving robust detection limits in complex clinical specimens such as blood,and demonstrating utility across a broad range of clinical applications.The ultrasensitivity of dELISA comes from partitioning single analytes,captured onto a microbead,into millions of compartments so that they can be counted individually.There is particular interest in using dELISA for multiplexed measurements,but generating and detecting the billions of compartments necessary to perform multiplexed ultrasensitive dELISA remains a challenge.To address this,we have developed a high-throughput,optofluidic platform that performs quantitative fluorescence measurements on five populations of microbeads,each encoded with distinct ratios of two fluorescent dyes,for digital assays.The key innovation of our work is the parallelization of droplet generation and detection,combined with time-domain encoding of the excitation sources into distinct patterns that barcode the emission signal of both dyes within each bead,achieving high throughput(6×10^(6) droplets/min)and accurate readout.Additionally,we modulate the exposure settings of the digital camera,capturing images of multiplexed beads and the droplet fluorescent substrate in consecutive frames,a method inspired by high dynamic range(HDR)photography.Our platform accurately classifies five populations of dual-encoded beads(accuracy>99%)and detects bead-bound streptavidin-horseradish peroxidase molecules in a third fluorescence channel.This work establishes the technological foundation to combine high multiplexing and high throughput for droplet digital assays.
基金National Natural Science Foundation of China(NSFC)(61805271)Guangdong Province Introduction of Innovative and Entrepreneurial Teams(2016ZT06D631)Shenzhen Science and Technology Innovation Commission(JCYJ20170818154035069)
文摘Bio-imaging generally indicates imaging techniques that acquire biological information from living forms.Recently, the ability to detect, diagnose, and monitor pathological, physiological, and molecular dynamics is in great demand, while scaling down the observing angle, achieving precise alignment, fast actuation, and a miniaturized platform become key elements in next-generation optical imaging systems. Optofluidics, nominally merging optic and microfluidic technologies, is a relatively new research field, and it has drawn great attention since the last decade. Given its abilities to manipulate both optic and fluidic functions/elements in the micro-/nanometer regime, optofluidics shows great potential in bio-imaging to elevate our cognition in the subcellular and/or molecular level. In this paper, we emphasize the development of optofluidics in bio-imaging, from individual components to representative applications in a more modularized, systematic sense. Further, we expound our expectations for the near future of the optofluidic imaging discipline.
基金financial supports from National Natural Science Foundation of China(62175023).
文摘In this study,we developed a single-beam optical trap-based surface-enhanced Raman scattering(SERS)optofluidic molecular fingerprint spectroscopy detection system.This system utilizes a single-beam optical trap to concentrate free silver nanoparticles(AgNPs)within an optofluidic chip,significantly enhancing SERS performance.We investigated the optical field distribution characteristics within the tapered fiber using COMSOL simulation software and established a MATLAB simulation model to validate the single-beam optical trap's effectiveness in capturing AgNPs,demonstrating the theoretical feasibility of our approach.To verify the particle capture efficacy of the system,we experimentally controlled the optical trap's on-off state to manage the capture and release of particles precisely.The experimental results indicated that the Raman signal intensity in the capture state was significantly higher than in the non-capture state,confirming that the single-beam optical trap effectively enhances the SERS detection capability of the optofluidic detection system.Furthermore,we employed Raman mapping techniques to investigate the impact of the capture area on the SERS effect,revealing that the spectral intensity of molecular fingerprints in the laser-trapping region is significantly improved.We successfully detected the Raman spectrum of crystal violet at a concentration of 10^(−9)mol/L and pesticide thiram at a concentration of 10^(−5)mol/L,further demonstrating the ability of the single-beam optical trap in enhancing the molecular fingerprint spectrum identification capability of the SERS optofluidic chips.The optical trapping SERS optofluidic detection system developed in this study,as a key component of an integrated optoelectronic sensing system,holds the potential for integration with portable high-power lasers and high-performance Raman spectrometers.This integration is expected to advance highly integrated technologies and significantly enhance the overall performance and portability of optoelectronic sensing systems.
基金supported by the National Natural Science Foundation of China(No.12174199)the Wanjing Horizontal Research and Development Fund for Nature(No.HJ1060319960015).
文摘Based on optofluidics and whispering gallery mode(WGM)theory,here an optofluidic refractive index sensor with microtube-coupled suspended core fiber(SCF)is proposed.It solves the issues of general sensors with microcavity-coupled fiber taper such as too fragile,unstable performance due to open coupling,poor portability and repeatability,while overcoming the poor performance of low refractive index sensing in general full-package fiber sensors.The sensor only needs a very small amount of liquid sample(about 1.8 nL).The proposed sensor combines the excellent performance of full package,optofluidics and WGM resonator.The resonant characteristics and sensing performance of the sensor are analyzed and discussed by the theoretical simulation.The simulation results indicate that the sensor has a wide refractive index sensing range(1.330-1.700)and good performance.The resonance wavelength shift has a good linear relationship with the liquid refractive index variation.In the low refractive index region,the sensitivity is 222.5-247.5 nm/RIU,Q-factor is 1.03×10^(3) and the detection limit is 3.64×10^(-4) RIU.In the medium and high refractive index regions,the sensitivity is 564.4-846.2 nm/RIU,Q-factor is up to 8.62×10^(4),and the detection limit can be as low as 1.29×10^(-6) RIU.The sensor exhibits a high sensitivity,a high Q-factor and a very low detection limit.
文摘A tunable plasmofluidic lens consisting of nanoslit arrays on a metal film is proposed for subwavelength imaging in far field at different wavelengths.The nanoslit arrays with constant depths but varying widths could generate desired optical phase retardations based on the propagation property of the surface plasmon polaritons(SPPs)through the metal-dielectric-metal(MDM)nanoslit waveguide.We demonstrate the tunability of the plasmofluidic lens for subwavelength imaging by changing the surrounding dielectric fluid.This work provides a novel approach for developing integrative tunable plasmofluidic lens for a variety of lab-on-chip applications.
文摘Optical axial scanning is essential process to obtain 3D information of biological specimens. To realize optical axial scanning without moving, the tunable lens is a solution. However, the conventional tunable lenses usually induce non-uniform magnification and resolution issues. In this paper, we report a movable electrowetting optofluidic lens. Unlike the conventional tunable lens, our proposed optofluidic lens has two liquid-liquid (L-L) interfaces, which can move in the cell by an external voltage. The object distance and image distance are adjusted by shifting the L-L interface position. Therefore, the proposed lens can realize optical axial scanning with uniform magnification and resolution in microscopy. To prove the concept, we fabricate an optofluidic lens and use it in optical axial scanning. The scanning distance is more than 1 mm with uniform magnification and good imaging quality. Widespread application of such a new adaptive zoom lens is foreseeable.
基金National Natural Science Foundation of China(12174107,11933005,61991444,12192251,12334014)National Key Research and Development Program of China(2019YFA0705000)Fundamental Research Funds for the Central Universities.
文摘Bending optofluidic waveguides are essential for developing high-performance fluid-based photonic circuits and systems.The combination of femtosecond(fs)-laser-assisted etching of high-precision microchannels and vacuum-assisted liquid-core filling allows the controllable fabrication of low-loss optofluidic waveguides in fused silica.
基金supported by the Heilongjiang Provincial Natural Science Foundation of China(Grant No.LH2021F019)Fundamental Research Funds for the Central Universities,China(Grant No.3072022CF2506)National Natural Science Foundation of China(Grant Nos.62305082,11574061,and 62065001).
文摘Optical fiber sensors have gained significant attention in recent years owing to their remarkable advantages of remote operation and rapid response.The integration of optical fiber sensing with the microfluidics technology has paved the way for the establishment of optical fiber optofluidic sensing.Optical fiber optofluidic systems possess the advantages of the low invasiveness,compact structure,excellent biocompatibility,and the ability to handle small analyte volumes,rendering them particularly suitable for serving as chemical sensors and biosensors.In this paper,we present an in-depth overview of optical fiber optofluidic chemical sensors and biosensors.Firstly,we provide a comprehensive summary of the types of optical fibers commonly employed in optofluidic chemical and biosensing,elucidating their distinct attributes and performance characteristics.Subsequently,we introduce and thoroughly analyze several representative sensing mechanisms employed in optical fiber optofluidic systems and main performance parameters.Furthermore,this review delves into the modification and functionalization of optical fibers.Additionally,we showcase typical biosensing and chemical sensing applications to demonstrate the practicality and versatility of optical fiber optofluidic sensing.Finally,the conclusion and outlook are given.
基金supported by the Outstanding Young Innovator Fund,Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences(to X.T.)the State Key Laboratory of Biomedical Imaging Science and System+5 种基金Shenzhen Basic Research Project of Natural Science Foundation(JCYJ20230808105701004 to Y.C.)Shenzhen Science and Technology Innovations Committee(JSGGZD20220822095200001 to H.Y.)National Science Foundation of China(32270937 to F.Y.)Ministry of Science and Technology of China(2021D0102 to Y.C.)Guangdong Basic and Applied Basic Research Foundation(2025A1515012136 to H.L.)Medicine Plus Program of Shenzhen University(2024YG015 to Y.C.).
文摘Infectious diseases such as coronavirus disease 2019(COVID-19)continue to pose significant global health challenges.Effective management of reinfection risks depends on sustained levels of binding and neutralizing antibodies.However,conventional methods—such as enzyme-linked immunosorbent assays(ELISA)and virus neutralization tests(VNT)—are limited by complex workflows,long assay durations,and high sample volume requirements,making them less suit-able for routine,decentralized,or time-sensitive surveillance.This study presents a custom-developed tip optofluidic immunoassay(TOI)platform that enables rapid,multiplexed antibody profiling using only 1 mL offingertip blood.The system integrates batch-fabricated microfluidic immunoreactors with a portable chemiluminescent imaging station,completing both binding and neutralization capability assessments within 40 min.TOI achieves a broad dynamic range(3–4 orders of magnitude),high signal-to-noise ratio(10,000),and excellent sensitivity for immunoglobulin G(IgG)detection.A renovated version of the rapid in vitro inhibition assay(RIVIA)is incorporated to evaluate neutralizing an-tibodies against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)with greater speed and cost-effi-ciency.In clinical studies,TOI successfully quantified antibody protection against multiple variants,identifying individ-uals with broad-spectrum immunity to both wild-type and XBB strains.With its high-precision,rapid turnaround,and minimal sample requirement,TOI offers a valuable tool for decentralized immune surveillance and personalized immu-nization strategy development.
基金supported by the National Research Foundation of Korea(NRF)Grant funded by the Korea Government(NRF-2020R1C1C1005505 and NRF-2022R1F1A106519512).
文摘Developing a portable yet affordable method for the discrimination of chemical substances with good sensitivity and selectivity is essential for on-site visual detection of unknown substances.Herein,we propose an optofluidic paper-based analytical device(PAD)that consists of a macromolecule-driven flow(MDF)gate and photonic crystal(PhC)coding units,enabling portable and scalable detection and discrimination of various organic chemical,mimicking the olfactory system.The MDF gate is designed for precise flow control of liquid analytes,which depends on intermolecular interactions between the polymer at the MDF gate and the liquid analytes.Subsequently,the PhC coding unit allows for visualizing the result obtained from the MDF gate and generating differential optical patterns.We fabricate an optofluidic PAD by integrating two coding units into a three-dimensional(3D)microfluidic paper within a 3D-printed cartridge.The optofluidic PADs clearly distinguish 11 organic chemicals with digital readout of pattern recognition from colorimetric signals.We believe that our optofluidic coding strategy mimicking the olfactory system opens up a wide range of potential applications in colorimetric monitoring of chemicals observed in environment.
文摘We have developed a self-contained,liquid tunable microlens based on polyacrylate membranes integrated with compact on-chip thermo-pneumatic actuation fabricated using full-wafer processing.Silicone oil is used as the optical liquid,which is pushed or pulled into the lens cavity via an extended microfluidic channel structure without any pumps,valves or other mechanical means.The heat load generated by the thermal actuator is physically isolated from the lens chamber.The back focal length may be tuned from infinity to 4 mm with a maximum power consumption of 300 mW.The principal application is fine tuning of the back focal length,for which tuning time constants as small as 100 ms are suitable.
基金supported by the DARPA Defense Sciences Office NAC(HR00112090009)NLM Programs,the Office of Naval Research(ONR)+5 种基金the National Science Foundation(NSF),grants CBET-1704085,DMR-1707641,NSF ECCS-180789,NSF ECCS-190184,NSF ECCS-2023730the Army Research Office(ARO)the San Diego Nanotechnology Infrastructure(SDNI)supported by the NSF National Nanotechnology Coordinated Infrastructure(grant ECCS-2025752)the Quantum Materials for Energy Efficient Neuromorphic Computing-an Energy Frontier Research Center,funded by the U.S.Department of Energy(DOE)Office of Science,Basic Energy Sciences,under award#DE-SC0019273the Cymer Corporation。
文摘Understanding light–matter interaction lies at the core of our ability to harness physical effects and to translate them into new capabilities realized in modern integrated photonics platforms.Here,we present the design and characterization of optofluidic components in an integrated photonics platform and computationally predict a series of physical effects that rely on thermocapillary-driven interaction between waveguide modes and topography changes of optically thin liquid dielectric film.Our results indicate that this coupling introduces substantial self-induced phase change and transmittance change in a single channel waveguide,transmittance through the Bragg grating waveguide,and nonlocal interaction between adjacent waveguides.We then employ the self-induced effects together with the inherent built-in finite relaxation time of the liquid film,to demonstrate that the light-driven deformation can serve as a reservoir computer capable of performing digital and analog tasks,where the gas–liquid interface operates both as a nonlinear actuator and as an optical memory element.
基金We thank Iain Patten for valuable discussions on the structure and layout of the manuscript.IDS kindly acknowledges funding from the Life grant by Volkswagen Foundation(Grant No.92772).
文摘The use of optical tweezers to measure forces acting upon microscopic particles has revolutionised fields from material science to cell biology.However,despite optical control capabilities,this technology is highly constrained by the material properties of the probe,and its use may be limited due to concerns about the effect on biological processes.Here we present a novel,optically controlled trapping method based on light-induced hydrodynamic flows.Specifically,we leverage optical control capabilities to convert a translationally invariant topological defect of a flow field into an attractor for colloids in an effectively one-dimensional harmonic,yet freely rotatable system.Circumventing the need to stabilise particle dynamics along an unstable axis,this novel trap closely resembles the isotropic dynamics of optical tweezers.Using magnetic beads,we explicitly show the existence of a linear force-extension relationship that can be used to detect femtoNewton-range forces with sensitivity close to the thermal limit.Our force measurements remove the need for laser-particle contact,while also lifting material constraints,which renders them a particu-larly interesting tool for the life sciences and engineering.
基金the Defense Advanced Research Projects Agency(DARPA)DSO’s NAC(HR00112090009)NLM,the U.S.Office of Naval Research(ONR)Multidisciplinary University Research Initiative(MURI),the U.S.National Science Foundation(NSF)Grant Nos.CCF-1640227the Semiconductor Research Corporation(SRC),and the Cymer Corporation.The authors have no relevant financial interests in the manuscript and no other potential conflicts of interest to disclose.
文摘Optical metamaterials and metasurfaces,which emerged in the course of the last few decades,have revolutionized our understanding of light and light–matter interaction.While solid materials are naturally employed as key building elements for construction of optical metamaterials mainly due to their structural stability,practically no attention was given to study of liquid-made optical two-dimensional(2-D)metasurfaces and the underlying interaction regimes between surface optical modes and liquids.We theoretically demonstrate that surface plasmon polaritons and slab waveguide modes that propagate within a thin liquid dielectric film trigger optical self-induced interaction facilitated by surface tension effects,which leads to the formation of 2-D optical liquid-made lattices/metasurfaces with tunable symmetry and can be leveraged for tuning of lasing modes.Furthermore,we show that the symmetry breaking of the 2-D optical liquid lattice leads to phase transition and tuning of its topological properties,which allows the formation,destruction,and movement of Dirac-points in the k-space.Our results indicate that optical liquid lattices support extremely low lasing threshold relative to solid dielectric films and have the potential to serve as configurable analogous computation platform.
基金supported by the Priority Program‘Active Micro-optics’funded by the German Research Foundation(DFG).
文摘We demonstrate a tunable imaging system based on the functionality of the mammalian eye using soft-matter micro-optical components.Inspired by the structure of the eye,as well as by the means through which nature tunes its optical behavior,we show that the technologies of microsystems engineering and micro-optics may be used to realize a technical imaging system whose biomimetic functionality is entirely distinct from that of conventional optics.The engineered eyeball integrates a deformable elastomeric refractive structure whose shape is mechanically controlled through application of strain using liquid crystal elastomer(LCE)actuators;two forms of tunable iris,one based on optofluidics and the other on LCEs with embedded heaters;a fixed lens arrangement;and a commercial imaging sensor chip.The complete microsystem,optimized to yield optical characteristics close to those of the human eye,represents the first fully functional,soft-matter-based tunable single-aperture eye-like imager.
基金funded by the German Research Foundation DFG within the Priority Program Active Micro-optics(SPP 1337).
文摘The shape of liquid interfaces can be precisely controlled using electrowetting,an actuation mechanism which has been widely used for tunable optofluidic micro-optical components such as lenses or irises.We have expanded the considerable flexibility inherent in electrowetting actuation to realize a variable optofluidic slit,a tunable and reconfigurable two-dimensional aperture with no mechanically moving parts.This optofluidic slit is formed by precisely controlled movement of the liquid interfaces of two highly opaque ink droplets.The 1.5mmlong slit aperture,with controllably variable discrete widths down to 45 mm,may be scanned across a length of 1.5mmwith switching times between adjacent slit positions of less than 120 ms.In addition,for a fixed slit aperture position,the width may be tuned to a minimum of 3 mmwith high uniformity and linearity over the entire slit length.This compact,purely fluidic device offers an electrically controlled aperture tuning range not achievable with extant mechanical alternatives of a similar size.
文摘We discuss the implementation and performance of an adaptive optics(AO)system that uses two cascaded deformable phase plates(DPPs),which are transparent optofluidic phase modulators,mimicking the common woofer/tweeter-type astronomical AO systems.One of the DPPs has 25 electrodes forming a keystone pattern best suited for the correction of low-order and radially symmetric modes;the second device has 37 hexagonally packed electrodes better suited for high-order correction.We also present simulation results and experimental validation for a new open-loop control strategy enabling simultaneous control of both DPPs,which ensures optimum correction for both large-amplitude low-order,and complex combinations of low-and high-order aberrations.The resulting system can reproduce Zernike modes up to the sixth radial order with stroke and fidelity up to twice better than what is attainable with either of the DPPs individually.The performance of the new AO configuration is also verified in a custom-developed fluorescence microscope with sensorless aberration correction.
基金This work was supported by JSPS KAKENHI Grant Number 25286038.
文摘The high-precision integration of three-dimensional(3D)microoptical components into microfluidics in a customizable manner is crucial for optical sensing,fluorescence analysis,and cell detection in optofluidic applications;however,it remains challenging for current microfabrication technologies.This paper reports the in-channel integration of flexible two-dimensional(2D)and 3D polymer microoptical devices into glass microfluidics by developing a novel technique:flat scaffold-supported hybrid femtosecond laser microfabrication(FSS-HFLM).The scaffold with an optimal thickness of 1–5 μm is fabricated on the lower internal surface of a microfluidic channel to improve the integration of high-precision microoptical devices on the scaffold by eliminating any undulated internal channel surface caused by wet etching.As a proof of demonstration,two types of typical microoptical devices,namely,2D Fresnel zone plates(FZPs)and 3D refractive microlens arrays(MLAs),are integrated.These devices exhibit multicolor focal spots,elongated(>three times)focal length and imaging of the characters‘RIKEN’in a liquid channel.The resulting optofluidic chips are further used for coupling-free white-light cell counting with a success rate as high as 93%.An optofluidic system with two MLAs and a W-filter is also designed and fabricated for more advanced cell filtering/counting applications.
基金from the National Natural Science Foundation of China(21874096,21575095,51602305,61604102 and 61875139)the 111 Project,and the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)+2 种基金the China Postdoctoral Science Foundation(2018M633118)Shenzhen Nanshan District Pilotage Team Program(LHTD20170006)Australian Research Council(ARC,FT150100450,IH150100006 and CE170100039).Q.Bao acknowledges support from the Australian Research Council(ARC)Centre of Excellence in Future Low-Energy Electronics Technologies(FLEET).
文摘The ultrafast monitoring of deoxyribonucleic acid(DNA)dynamic structural changes is an emerging and rapidly growing research topic in biotechnology.The existing optical spectroscopy used to identify different dynamical DNA structures lacks quick response while requiring large consumption of samples and bulky instrumental facilities.It is highly demanded to develop an ultrafast technique that monitors DNA structural changes with the external stimulus or cancer-related disease scenarios.Here,we demonstrate a novel photonic integrated graphene-optofluidic device to monitor DNA structural changes with the ultrafast response time.Our approach is featured with an effective and straightforward design of decoding the electronic structure change of graphene induced by its interactions with DNAs in different conformations using ultrafast nanosecond pulse laser and achieving refractive index sensitivity of~3×10^(−5) RIU.This innovative technique for the first time allows us to perform ultrafast monitoring of the conformational changes of special DNA molecules structures,including G-quadruplex formation by K+ions and i-motif formation by the low pH stimulus.The graphene-optofluidic device as presented here provides a new class of label-free,ultrafast,ultrasensitive,compact,and cost-effective optical biosensors for medical and healthcare applications.
