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DOI

Development of Elastomeric Optofluidic Devices for Lasing and Sensing

01 Jan 2012-
TL;DR: In this article, a batch of optofluidic devices that are based on PDMS material and soft-lithography are presented, which can provide a broad spectrum of toolbox with different optical functions that can be easily integrated into many other PDMS microfluidic chips.
Abstract: The term of optofluidics defines an emergent research field that combines microfluidics and optics. In many lab-on-a-chip applications, these two technologies are used in combining the microfluidics for sample delivery and optics for sensing and controlling. Optofluidic represents the implementation of optics in microfluidic platform that produces an unprecedented level of integration. Moreover, optofluidic devices are easily and highly reconfigurable, which can be a significant advantage to the traditional solid optical components. As an elastomer, PDMS (polydimethylsiloxane) is one of the most popular materials in microfluidics. It exhibits excellent elasticity, bio-compatibility and optical transparence. Most microfluidic chips are made of PDMS using soft lithography. And multi-layer soft lithography has enabled large-scale integration of monolithic microfluidic valves and pumps on a single chip. Thus to develop the optofluidic elements within PDMS microfluidic chip is one of the most promising and desirable ways towards further integration of optofluidic and microfluidic functions together for more complex lab-on-a-chip applications. During my doctoral research, we worked on a batch of optofluidic devices that are based on PDMS material and soft lithography. They include the optofluidic dye lasers, optofluidic interferometer, optofluidic switch, and optofluidic differential spectroscopy. Such optofluidic elements provide a broad spectrum of toolbox with different optical functions that can be easily into many other PDMS microfluidic chips. They are compatible to the conventional PDMS microfluidic chip in terms of fabrication, operation and control. And they could provide important optical functions in lab-on-a-chip systems. For examples, the optofluidic dye laser can be integrated as a widely tunable coherent source for chip-scale fluorescence spectroscopy or cell flow cytometry. The optofluidic membrane interferometer can be easily integrated into conventional PDMS microfluidic chip for multi-site pressure and flow monitoring with high precision. Optofluidic switch can compose a reconfigurable optical circuit on single microfluidic chip. Optofluidic differential spectroscopy provides a simple and highly sensitive method for in-line measuring of solution concentration. Among these devices, we have also developed and summarized a series of novel optofluidic turning methods that are controlled by pneumatic actuation. These simple turning methods also take the advantages of high precision and reliability. In addition to these elastomeric optofluidic devices, we are also working on several other optofluidic projects. In the last chapter of this thesis, we will give a partial preview of these works and also our perspective on the nano-optofluidics which represents a new trend of optofluidics.
Citations
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01 Jan 2007
TL;DR: In this paper, the authors proposed a recursive positioning of air mirrors, propagating multiple internal reflection (PMIR) systems for high-sensitivity measurements, and the results confirm the validity of the proposed system for high sensitivity measurements.
Abstract: Compact poly(dimethylsiloxane)-based (PDMS) multiple internal reflection systems which comprise self-alignment systems, lenses, microfluidic channels and mirrors have been developed for highly sensitive absorbance measurements. With the proper definition of air mirrors at both sides of the sensing region, the optical path of the light from the LED has been meaningfully lengthened without a dramatic increase of the mean flow cell volume. By recursive positioning of such air mirrors, propagating multiple internal reflection (PMIR) systems have been designed, simulated and characterized. Experimental results confirm the ray-tracing predictions and allow the determining that there are some regions of the mean flow cell volume that do not contribute to the increase of the sensitivity. The tailoring of the sensing region, following the optical path, results in a similar limit of detection (110 nM) for fluorescein diluted in phosphate buffer. Finally, a ring configuration, labelled RMIR, has also been developed. With the addition of a third air mirror, the LOD can be decreased to 41 nM with the additional advantage of a substantial decrease of the length of the sensing region. These results confirm the validity of the proposed systems for high sensitivity measurements.

93 citations

Journal Article
TL;DR: In this article, a high-speed microfluidic approach for measuring dynamical pressure drop variations along a micrometer-sized channel was proposed and demonstrated by presenting measurements of the additional pressure drop produced at the scale of individual flowing cells.
Abstract: We propose a broadly applicable high-speed microfluidic approach for measuring dynamical pressure-drop variations along a micrometer-sized channel and illustrate the potential of the technique by presenting measurements of the additional pressure drop produced at the scale of individual flowing cells. The influence of drug-modified mechanical properties of the cell membrane is shown. Finally, single hemolysis events during flow are recorded simultaneously with the critical pressure drop for the rupture of the membrane. This scale-independent measurement approach can be applied to any dynamical process or event that changes the hydrodynamic resistance of micro- or nanochannels.

20 citations

Proceedings Article
04 May 2008
TL;DR: Optofluidic 1x4 switch made of a blazed grating in silicon elastomer integrated with microfluidic channel was designed, fabricated and tested as mentioned in this paper, and experiments show 1.7dB insertion loss, extinction ratio of 9.8dB, and response time of 60ms.
Abstract: Optofluidic 1x4 switch made of a blazed grating in silicon elastomer integrated with microfluidic channel was designed, fabricated and tested. Experiments show 1.7dB insertion loss, extinction ratio of 9.8dB, and response time of 60ms.

8 citations

06 May 2005
TL;DR: Remote detection of the NMR signal both overcomes the sensitivity limitation of NMR and enables time-of-flight measurement in addition to spatially resolved imaging, gaining detailed insight into the effects of flow, diffusion, and mixing in specific geometries.
Abstract: Miniaturized fluid handling devices have recently attracted considerable interest in many areas of science1. Such microfluidic chips perform a variety of functions, ranging from analysis of biological macromolecules2,3 to catalysis of reactions and sensing in the gas phase4,5. To enable precise fluid handling, accurate knowledge of the flow properties within these devices is important. Due to low Reynolds numbers, laminar flow is usually assumed. However, either by design or unintentionally, the flow characteristic in small channels is often altered, for example by surface interactions, viscous and diffusional effects, or electrical potentials. Therefore, its prediction is not always straight-forward6-8. Currently, most microfluidic flow measurements rely on optical detection of markers9,10, requiring the injection of tracers and transparent devices. Here, we show profiles of microfluidic gas flow in capillaries and chip devices obtained by NMR in the remote detection modality11,12. Through the transient measurement of dispersion13, NMR is well adaptable for non-invasive, yet sensitive determination of the flow field and provides a novel and potentially more powerful tool to profile flow in capillaries and miniaturized flow devices.

6 citations

References
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Book
01 Jan 1978
TL;DR: This book presents those parts of the theory which are especially useful in calculations and stresses the representation of splines as linear combinations of B-splines as well as specific approximation methods, interpolation, smoothing and least-squares approximation, the solution of an ordinary differential equation by collocation, curve fitting, and surface fitting.
Abstract: This book is based on the author's experience with calculations involving polynomial splines. It presents those parts of the theory which are especially useful in calculations and stresses the representation of splines as linear combinations of B-splines. After two chapters summarizing polynomial approximation, a rigorous discussion of elementary spline theory is given involving linear, cubic and parabolic splines. The computational handling of piecewise polynomial functions (of one variable) of arbitrary order is the subject of chapters VII and VIII, while chapters IX, X, and XI are devoted to B-splines. The distances from splines with fixed and with variable knots is discussed in chapter XII. The remaining five chapters concern specific approximation methods, interpolation, smoothing and least-squares approximation, the solution of an ordinary differential equation by collocation, curve fitting, and surface fitting. The present text version differs from the original in several respects. The book is now typeset (in plain TeX), the Fortran programs now make use of Fortran 77 features. The figures have been redrawn with the aid of Matlab, various errors have been corrected, and many more formal statements have been provided with proofs. Further, all formal statements and equations have been numbered by the same numbering system, to make it easier to find any particular item. A major change has occured in Chapters IX-XI where the B-spline theory is now developed directly from the recurrence relations without recourse to divided differences. This has brought in knot insertion as a powerful tool for providing simple proofs concerning the shape-preserving properties of the B-spline series.

10,258 citations


"Development of Elastomeric Optoflui..." refers methods in this paper

  • ...In order to enhance the accuracy, a third order polynomial (cubic spline) interpolation was employed [87]....

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Journal ArticleDOI
27 Jul 2006-Nature
TL;DR: The manipulation of fluids in channels with dimensions of tens of micrometres — microfluidics — has emerged as a distinct new field that has the potential to influence subject areas from chemical synthesis and biological analysis to optics and information technology.
Abstract: The manipulation of fluids in channels with dimensions of tens of micrometres--microfluidics--has emerged as a distinct new field. Microfluidics has the potential to influence subject areas from chemical synthesis and biological analysis to optics and information technology. But the field is still at an early stage of development. Even as the basic science and technological demonstrations develop, other problems must be addressed: choosing and focusing on initial applications, and developing strategies to complete the cycle of development, including commercialization. The solutions to these problems will require imagination and ingenuity.

8,260 citations


"Development of Elastomeric Optoflui..." refers background in this paper

  • ...Optical absorbance measurement is also a very common way to determine protein’s concentration in water solution [109-110]; Integration of optical functions with microfluidic has been becoming an important approach in developing “Lab-on-a-chip” devices [111-113]....

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  • ...52 As a fast-growing field, microfluidics and lab on chip systems have found numerous applications in the areas of biochemical detection, analysis, synthesis and separations [3, 67-69]....

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  • ...They also hold the promise of integrating an entire laboratory onto a single chip which is so called “Lab-on-a-chip” [3, 104-105]....

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  • ...The field of optofluidics formally began to emerge in the mid-2000s when the fields of microfluidics and micro/nano photonics were maturing and the researchers began to look for the synergies between these two areas [2-4]....

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Book
01 Jan 1965
TL;DR: Low Reynolds number flow theory finds wide application in such diverse fields as sedimentation, fluidization, particle-size classification, dust and mist collection, filtration, centrifugation, polymer and suspension rheology, and a host of other disciplines.
Abstract: Low Reynolds number flow theory finds wide application in such diverse fields as sedimentation, fluidization, particle-size classification, dust and mist collection, filtration, centrifugation, polymer and suspension rheology, flow through porous media, colloid science, aerosol and hydrosal technology, lubrication theory, blood flow, Brownian motion, geophysics, meteorology, and a host of other disciplines. This text provides a comprehensive and detailed account of the physical and mathematical principles underlying such phenomena, heretofore available only in the original literature.

4,648 citations


"Development of Elastomeric Optoflui..." refers background in this paper

  • ...For a steady laminar flow in a rectangular channel with constant cross-sectional areas, the pressure gradient is linearly proportional to the flow rate Q [88],...

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Journal ArticleDOI
Ekmel Ozbay1
13 Jan 2006-Science
TL;DR: The current status and future prospects of plAsmonics in various applications including plasmonic chips, light generation, and nanolithography are reviewed.
Abstract: Electronic circuits provide us with the ability to control the transport and storage of electrons. However, the performance of electronic circuits is now becoming rather limited when digital information needs to be sent from one point to another. Photonics offers an effective solution to this problem by implementing optical communication systems based on optical fibers and photonic circuits. Unfortunately, the micrometer-scale bulky components of photonics have limited the integration of these components into electronic chips, which are now measured in nanometers. Surface plasmon-based circuits, which merge electronics and photonics at the nanoscale, may offer a solution to this size-compatibility problem. Here we review the current status and future prospects of plasmonics in various applications including plasmonic chips, light generation, and nanolithography.

4,371 citations


"Development of Elastomeric Optoflui..." refers background in this paper

  • ...Different from traditionally optics where the light can be only controlled on the length scale down to a little below of optical diffraction limit, a new paradigm called plasmonics is emerging [138]....

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Journal ArticleDOI
07 Apr 2000-Science
TL;DR: An extension to the soft lithography paradigm, multilayersoft lithography, with which devices consisting of multiple layers may be fabricated from soft materials is described, to build active microfluidic systems containing on-off valves, switching valves, and pumps entirely out of elastomer.
Abstract: Soft lithography is an alternative to silicon-based micromachining that uses replica molding of nontraditional elastomeric materials to fabricate stamps and microfluidic channels. We describe here an extension to the soft lithography paradigm, multilayer soft lithography, with which devices consisting of multiple layers may be fabricated from soft materials. We used this technique to build active microfluidic systems containing on-off valves, switching valves, and pumps entirely out of elastomer. The softness of these materials allows the device areas to be reduced by more than two orders of magnitude compared with silicon-based devices. The other advantages of soft lithography, such as rapid prototyping, ease of fabrication, and biocompatibility, are retained.

4,218 citations


"Development of Elastomeric Optoflui..." refers background or methods in this paper

  • ...As being compatible with the normal microfluidic in terms of both fabrication and characterization [20], this device can be easily integrated into a lab-on-a-chip system for in situ measuring the pressure and flow rate....

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  • ...The optofluidic chip was fabricated by multilayer soft lithography (MSL), which has been widely utilized to make the membrane valves and pumps on microfluidic devices [20]....

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  • ...For example, the compressed air has become one of the dominated methods to manipulate the liquid analyte for lab-on-a-chip applications, either by pushing the liquid directly or by actuating the membrane valve [20, 57]....

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  • ...Such pneumatically control has been widely utilized in microfluidic chips for fluid control based on the membrane valves and pumps [20]....

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  • ...Multilayer soft lithography was utilized for chip fabrication [20, 123]....

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