The authors would like to thank Professor Yuzuru Takashima at the University of Arizona for discussions on optical imaging, Mr. Karl Urbanek for assistance with high power lasers, and Max Yuen for discussions of Brownian motion. The authors send further thanks to Professor Kenneth Crozier at Harvard University for helpful discussions on optical trapping experiments. Funding was provided in part by the United States National Science Foundation (award number 1028372).

<ol>
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The authors have nothing to disclose.

NOCBのみ、従来の集束ビーム技術のための長い利用可能な粒子を輸送するために強力なトラップ力と能力を備えたプラズモニックアプローチの小さなトラップサイズを兼ね備えています。 NOCBにユニークな、システムのトラップおよび輸送特性は、表面パターンの結果ではなく、照射ビームを整形します。提供される照明は十分に明るく、その偏光または波長を調節することができる粒子が保...

シングルナノ粒子の捕獲、尋問や操作はナノテクノロジーの成長に重要です。光ピンセットは、彼らがそのような単一DNA分子4の機械的特性の測定などの画期的な実験を有効にしている分子生物学1-4、5-7化学とナノアセンブリ7-10に実験に特に成功した操作技術となっていると、その光学特性11,12による細胞の選別。これらのフロンティア上の発見があっても小規模なシステムの研究を開き、彼らは新しい事実上有益な製品や技術のエンジニアリングのための方法を作ります。今度は、この傾向はより小さく、より基本的な粒子を操作するための新しい技術の必要性を駆動します。また、外の化学的および生物学的試験をもたらすために、より安く、より小さなパッケージでこれらの機能を実行するには、「ラボオンチップ」デバイスを構築するためのプッシュがあります医療や他の目的13,14のための実験室とフィールドへ。 残念ながら、従来の光トラッピング（COT）は、ナノテクノロジーの増大する要求をすべて満たすことができません。 COTは、光強度と電磁界エネルギーの高い勾配の局所的ピークを作成し、タイトな焦点にレーザー光をもたらすために、高開口数（NA）の対物レンズを使用するメカニズムで動作します。これらのエネルギー密度勾配は、一般に、焦点の中心に向かってそれらを描画する光散乱粒子上に正味の力を及ぼします。小さい粒子を捕捉することは、より高い光パワーやタイトなフォーカスが必要です。しかし、光の集束ビームの焦点の最小サイズを制限し、エネルギー密度勾配に上限を課す回折の原理を、従います。 COTが効率的にトラップ小さなオブジェクトをすることができず、COTのトラブル近接した粒子とを判別、トラッピング解像度を持っています。これは、2つの即時の結果を有します制限は「脂肪指の問題として知られています。さらに、COTで複数の粒子トラップの実装は大幅に光トラッピングシステムのコストと複雑さを増大させるビームステアリング光学素子または空間光変調器、コンポーネントのシステムを必要とします。 光の従来の集束ビームの基本的な制限を回避する1つの方法は、ファーフィールドに伝播するように言った、代わりに近接場光学電磁エネルギーの勾配を利用することです。近接場は、非常にこれらの供給源に局在し、それは、そのエネルギー密度が非常に高い勾配を示すだけでなくことを意味し、指数関数的に離れた電磁界の発生源から減衰します。さらに近いINFRで金と銀のプラズモン作用によって強化された近くに、このようなボウタイ開口、ナ​​ノ柱、およびC形の彫刻などのナノ金属共振器の分野、電磁エネルギーの異常な濃度を示すことが示されています、aredと光の波長。これらの共振器は、高効率と解像度15-22のトラップ非常に小さい粒子に使用されています。この技術は、小さな粒子を捕捉するのに有効であることが証明されているが、それはまた、近接場システムは、遠視野システムまたはマイクロ流体とインターフェースするようにされている場合に必要となる、かなりの範囲に亘って粒子を輸送する能力が制限されることが証明されています。 最近、我々のグループは、この問題に対する解決策を提案しています。共振器は、互いに非常に近接して配置される場合、粒子は、原理的には表面から放出されることなく、次の1つの近接場光トラップから移動することができます。隣接トラップが別々にオン・オフすることができれば搬送方向を決定することができます。各共振器は、そのネイバーとは異なる光の偏光または波長に敏感である、三つ以上のアドレス可能な共振器の線形アレイは、nanopartiを輸送、光コンベヤーベルトとして機能しますチップ上に数ミクロンの距離にわたってクル。 それが所定の位置に粒子を保持することができ、それはまた、パターン化されたトラックに沿って高速で移動したりすることができ、収集または粒子を分散させるだけでなく、として、いわゆる「ナノ光コンベヤーベルト」（NOCB）は、プラズモン共振器の捕獲スキームの中で一意ですミックスし、それらをキューに入れ、さらにはそのような彼らのモビリティ23などの特性により、それらを並べ替えます。これらの機能の全ては、ビームステアリング光学系を必要とせず、照明の偏光又は波長を調節することによって制御されます。近接場光学トラップとして、NOCB捕捉分解能は、従来の集束ビーム光トラップよりも高いので、近接した粒子を区別することができます。それがうまくトラップに光を集中させる金属ナノ構造を使用しているため、それが電力効率であり、そのような高NAの対物レンズなどの高価な光学部品を必要としません。さらに、多くのNOCBsは高い充填デンで、並列に動作することができます同一基板上にsity、および電源の1 Wは1200以上の開口部23を駆動することができます。 我々は最近、スムーズに4.5μmのトラック24に沿って前後にナノ粒子を推進、第一の偏光駆動型NOCBを示しました。この記事では、光学的に、デバイスを設計し、製造するために必要な手順を提示し、それを活性化し、輸送実験を再現します。我々は、この技術が広く利用できるようにするマイクロフルイディクス、遠視野光学、ナノスケールデバイスと実験の間のサイズのギャップを埋めるのに役立ちますことを願っています。

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>HSQ e-beam resist</td>
			<td>Dow Corning</td>
			<td>XR-1541-006</td>
			<td></td>
		</tr>
		<tr>
			<td>PMMA</td>
			<td>MicroChem</td>
			<td>950A2 M230002</td>
			<td></td>
		</tr>
		<tr>
			<td>Fast curing optical adhesive</td>
			<td>Norland Optical Adhesive</td>
			<td>NOA 81</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescent carboxyl microspheres</td>
			<td>Bangs Laboratories</td>
			<td>FC02F, FC03F</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescent carboxylate-modified microspheres</td>
			<td>Molecular Probes</td>
			<td>F-8888</td>
			<td></td>
		</tr>
		<tr>
			<td>Quartz slide</td>
			<td>SPI Supplies</td>
			<td>1020-AB</td>
			<td></td>
		</tr>
		<tr>
			<td>Inverted fluorescent microscope</td>
			<td>Nikon</td>
			<td>ECLIPSE TE2000-U</td>
			<td></td>
		</tr>
		<tr>
			<td>Nd:YAG laser</td>
			<td>Lightwave Electronics</td>
			<td>221-HD-V04</td>
			<td></td>
		</tr>
		<tr>
			<td>sCMOS camera</td>
			<td>PCO</td>
			<td>EDGE55</td>
			<td></td>
		</tr>
		<tr>
			<td>CCD camera</td>
			<td>Watec</td>
			<td>WAT-120N</td>
			<td></td>
		</tr>
		<tr>
			<td>Zero-order half-wave plate</td>
			<td>Thorlabs</td>
			<td>WPH05M-1064</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma-Aldrich</td>
			<td>T8787</td>
			<td></td>
		</tr>
		<tr>
			<td>Distilled water</td>
			<td>Invitrogen</td>
			<td>10977-023</td>
			<td></td>
		</tr>
		<tr>
			<td>Si Wafer</td>
			<td>Silicon Quest International</td>
			<td>708069</td>
			<td></td>
		</tr>
		<tr>
			<td>Optical lenses</td>
			<td>Thorlabs</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

fabrication and operation of a nano-optical conveyor belt

トラップに集束レーザービームを用いる技術と小さな粒子に力を発揮するには、過去数十年にわたりナノスケールの生物学的および物理学の多くの重要な発見を可能にしました。この分野での進展をより容易に分散され、より広く利用可能にすることができたツールを使って、さらに小さなシステムの、大規模でのさらなる研究を誘います。トラップにハード直径半波長よりも粒子が小さくなり、一般に、1つの半分以上互いに接近している粒子とを区別からオペレータを防ぎ、レーザビームの焦点スポットの残念ながら、回折限界の基本法則は、最小サイズ、 -wavelength。これは、多くの密集したナノ粒子の光学的操作を排除し、光学機械システムの分解能を制限します。また、収束ビームを使用して操作が非常にかさばるし、高価になることができ、ビーム形成またはステアリング光学系を必要とします。対処するために、これらの制限は、従来の光トラッピングのシステムのスケーラビリティに私たちの研究室は、チップ全体の粒子を移動させるために、近接場光学系を利用した代替技術を考案しました。代わりに、遠視野でのレーザビームの集束、プラズモン共振器の近接場光は、回折の制限を克服し、より高い解像度で粒子を操作するために必要な局所光強度強化を生み出します。密集した共振器は、コンベヤーベルト状の次に1からの粒子のハンドオフを媒介するために対処することができる強力な光トラップを生成します。ここでは、設計と生産プラズモンC字型共振器を用いてパターニング金表面を使用して、コンベアベルトをし、超解像のナノ粒子の操作と輸送を達成するために、偏光レーザ光とそれを操作する方法する方法について説明します。ナノ光学コンベヤベルトチップは、リソグラフィー技術を用いて製造され、容易にパッケージ化して配布することができます。

図7は 、最終的なデバイスの写真です。 cmで1×1 cmでの中心金表面にわずかに傾斜した図から分かるCSEコンベヤパターンの行列である。 図6に、最終的なデバイス例のCSEのパターンの走査型電子顕微鏡の画像です。 長さのナノ光コンベヤーベルト5μmの上を移動する390ナノメートルのポリスチレンビーズの粒子運動は、 図9に示されて?...

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Fabrication and Operation of a Nano-Optical Conveyor Belt

The scalability and resolution of conventional optical manipulation techniques are limited by diffraction. We circumvent the diffraction limit and describe a method of optically transporting nanoparticles across a chip using a gold surface patterned with a path of closely spaced C-shaped plasmonic resonators.

ナノ光学コンベヤーベルトの作製と運用

The technique of using focused laser beams to trap and exert forces on small particles has enabled many pivotal discoveries in the nanoscale biological ...

fabrication-and-operation-of-a-nano-optical-conveyor-belt

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Education

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Unit 1

Electromagnetic Waves

SCIENTISTS IN ACTION

11.5K ビュー.  Stanford University. The scalability and resolution of conventional optical manipulation techniques are limited by diffraction. We circumvent the diffraction limit and describe a method of optically transporting nanoparticles across a chip using a gold surface patterned with a path of closely spaced C-shaped plasmonic resonators.

ビデオ: Fabrication and Operation of a Nano-Optical Conveyor Belt

Fabrication, Densification, and Replica Molding of 3D Carbon Nanotube Microstructures

The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip devices, and their applications. In particular, capabilities for cost-effective fabrication of polymer microstructures were transformed by the advent of soft lithography and other micromolding techniques 1, 2, and this led a revolution in applications of microfabrication to biomedical engineering and biology. Nevertheless, it remains challenging to fabricate microstructures with well-defined nanoscale surface textures, and to fabricate arbitrary 3D shapes at the micro-scale. Robustness of master molds and maintenance of shape integrity is especially important to achieve high fidelity replication of complex structures and preserving their nanoscale surface texture. The combination of hierarchical textures, and heterogeneous shapes, is a profound challenge to existing microfabrication methods that largely rely upon top-down etching using fixed mask templates. On the other hand, the bottom-up synthesis of nanostructures such as nanotubes and nanowires can offer new capabilities to microfabrication, in particular by taking advantage of the collective self-organization of nanostructures, and local control of their growth behavior with respect to microfabricated patterns. 
Our goal is to introduce vertically aligned carbon nanotubes (CNTs), which we refer to as CNT "forests", as a new microfabrication material. We present details of a suite of related methods recently developed by our group: fabrication of CNT forest microstructures by thermal CVD from lithographically patterned catalyst thin films; self-directed elastocapillary densification of CNT microstructures; and replica molding of polymer microstructures using CNT composite master molds. In particular, our work shows that self-directed capillary densification ("capillary forming"), which is performed by condensation of a solvent onto the substrate with CNT microstructures, significantly increases the packing density of CNTs. This process enables directed transformation of vertical CNT microstructures into straight, inclined, and twisted shapes, which have robust mechanical properties exceeding those of typical microfabrication polymers. This in turn enables formation of nanocomposite CNT master molds by capillary-driven infiltration of polymers. The replica structures exhibit the anisotropic nanoscale texture of the aligned CNTs, and can have walls with sub-micron thickness and aspect ratios exceeding 50:1. Integration of CNT microstructures in fabrication offers further opportunity to exploit the electrical and thermal properties of CNTs, and diverse capabilities for chemical and biochemical functionalization 3.

We present methods for fabrication of patterned microstructures of vertically aligned carbon nanotubes (CNTs), and their use as master molds for production of polymer microstructures with organized nanoscale surface texture. The CNT forests are densified by condensation of solvent onto the substrate, which significantly increases their packing density and enables self-directed formation of 3D shapes.

製造、ち密化、および3Dカーボンナノチューブの微細構造のレプリカ成形

The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip ...

工学

Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing

This paper discusses fluorescent core microcavity-based sensors that can operate in a microfluidic analysis setup. These structures are based on the formation of a fluorescent quantum-dot (QD) coating on the channel surface of a conventional microcapillary. Silicon QDs are especially attractive for this application, owing in part to their negligible toxicity compared to the II-VI and II-VI compound QDs, which are legislatively controlled substances in many countries. While the ensemble emission spectrum is broad and featureless, an Si-QD film on the channel wall of a capillary features a set of sharp, narrow peaks in the fluorescence spectrum, corresponding to the electromagnetic resonances for light trapped within the film. The peak wavelength of these resonances is sensitive to the external medium, thus permitting the device to function as a refractometric sensor in which the QDs never come into physical contact with the analyte. The experimental methods associated with the fabrication of the fluorescent-core microcapillaries are discussed in detail, as well as the analysis methods. Finally, a comparison is made between these structures and the more widely investigated liquid-core optical ring resonators, in terms of microfluidic sensing capabilities.

Fluorescent-core microcavity sensors employ a high-index quantum-dot coating in the channel of silica microcapillaries. Changes in the refractive index of fluids pumped into the capillary channel cause shifts in the microcavity fluorescence spectrum that can be used to analyze the channel medium.

Refractometricセンシング用蛍光コアマイクロキャビティの合成と操作

This paper discusses  fluorescent core microcavity-based sensors that can operate in a microfluidic  analysis setup. These structures are based on the ...

Fabrication, Operation and Flow Visualization in Surface-acoustic-wave-driven Acoustic-counterflow Microfluidics

Surface acoustic waves (SAWs) can be used to drive liquids in portable microfluidic chips via the acoustic counterflow phenomenon. In this video we present the fabrication protocol for a multilayered SAW acoustic counterflow device. The device is fabricated starting from a lithium niobate (LN) substrate onto which two interdigital transducers (IDTs) and appropriate markers are patterned. A polydimethylsiloxane (PDMS) channel cast on an SU8 master mold is finally bonded on the patterned substrate. Following the fabrication procedure, we show the techniques that allow the characterization and operation of the acoustic counterflow device in order to pump fluids through the PDMS channel grid. We finally present the procedure to visualize liquid flow in the channels. The protocol is used to show on-chip fluid pumping under different flow regimes such as laminar flow and more complicated dynamics characterized by vortices and particle accumulation domains.

In this video we first describe fabrication and operation procedures of a surface acoustic wave (SAW) acoustic counterflow device. We then demonstrate an experimental setup that allows for both qualitative flow visualization and quantitative analysis of complex flows within the SAW pumping device.

表面弾性波駆動型アコースティック·逆流マイクロフルイディクスで製作、操作と流れの可視化

Surface acoustic waves (SAWs) can be used to drive liquids in portable microfluidic chips via the acoustic counterflow phenomenon. In this video we ...

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including microresonators. However, because of the increased acoustic radiative losses during direct liquid immersion of optomechanical devices, almost all published optomechanical experiments have been performed in solid phase. This paper discusses a recently introduced hollow microfluidic optomechanical resonator. Detailed methodology is provided to fabricate these ultra-high-Q microfluidic resonators, perform optomechanical testing, and measure radiation pressure-driven breathing mode and SBS-driven whispering gallery mode parametric vibrations. By confining liquids inside the capillary resonator, high mechanical- and optical- quality factors are simultaneously maintained.

Parametric optomechanical excitations have recently been experimentally demonstrated in microfluidic optomechanical resonators by means of optical radiation pressure and stimulated Brillouin scattering. This paper describes the fabrication of these microfluidic resonators along with methodologies for generating and verifying optomechanical oscillations.

作製とマイクロ流体光力学発振器のテスト

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including ...

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an elastomeric dielectric membrane sandwiched between two compliant electrodes. The large actuation strains of these transducers when used as actuators (over 300% area strain) and their soft and compliant nature has been exploited for a wide range of applications, including electrically tunable optics, haptic feedback devices, wave-energy harvesting, deformable cell-culture devices, compliant grippers, and propulsion of a bio-inspired fish-like airship. In most cases, DETs are made with a commercial proprietary acrylic elastomer and with hand-applied electrodes of carbon powder or carbon grease. This combination leads to non-reproducible and slow actuators exhibiting viscoelastic creep and a short lifetime. We present here a complete process flow for the reproducible fabrication of DETs based on thin elastomeric silicone films, including casting of thin silicone membranes, membrane release and prestretching, patterning of robust compliant electrodes, assembly and testing. The membranes are cast on flexible polyethylene terephthalate (PET) substrates coated with a water-soluble sacrificial layer for ease of release. The electrodes consist of carbon black particles dispersed into a silicone matrix and patterned using a stamping technique, which leads to precisely-defined compliant electrodes that present a high adhesion to the dielectric membrane on which they are applied.

This manuscript shows the fabrication process for the manufacture of dielectric elastomer soft actuators based on silicone membranes. The three key stages of production are presented in detail: blade casting of thin silicone membranes; pad printing of compliant electrodes; and the assembly of all the components.

シリコーン系誘電エラストマーアクチュエータの製造工程

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an ...

Fabrication and Operation of Acoustofluidic Devices Supporting Bulk Acoustic Standing Waves for Sheathless Focusing of Particles

Acoustophoresis refers to the displacement of suspended objects in response to directional forces from sound energy. Given that the suspended objects must be smaller than the incident wavelength of sound and the width of the fluidic channels are typically tens to hundreds of micrometers across, acoustofluidic devices typically use ultrasonic waves generated from a piezoelectric transducer pulsating at high frequencies (in the megahertz range). At characteristic frequencies that depend on the geometry of the device, it is possible to induce the formation of standing waves that can focus particles along desired fluidic streamlines within a bulk flow. Here, we describe a method for the fabrication of acoustophoretic devices from common materials and clean room equipment. We show representative results for the focusing of particles with positive or negative acoustic contrast factors, which move towards the pressure nodes or antinodes of the standing waves, respectively. These devices offer enormous practical utility for precisely positioning large numbers of microscopic entities (e.g., cells) in stationary or flowing fluids for applications ranging from cytometry to assembly.

Acoustofluidic devices use ultrasonic waves within microfluidic channels to manipulate, concentrate and isolate suspended micro and nanoscopic entities. This protocol describes the fabrication and operation of such a device supporting bulk acoustic standing waves to focus particles in a central streamline without the aid of sheath fluids.

作製とAcoustofluidicのデバイスの動作は、粒子のフォーカシングSheathlessためのバルク弾性定在波を支援

Acoustophoresis refers to the displacement of suspended objects in response to directional forces from sound energy. Given that the suspended objects must ...

Fabrication and Characterization of Superconducting Resonators

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors (MKIDs) for the detection of faint astrophysical signatures, as well as for quantum computing applications and materials characterization. In this paper, procedures are presented for the fabrication and characterization of thin-film superconducting microwave resonators. The fabrication methodology allows for the realization of superconducting transmission-line resonators with features on both sides of an atomically smooth single-crystal silicon dielectric. This work describes the procedure for the installation of resonator devices into a cryogenic microwave testbed and for cool-down below the superconducting transition temperature. The set-up of the cryogenic microwave testbed allows one to do careful measurements of the complex microwave transmission of these resonator devices, enabling the extraction of the properties of the superconducting lines and dielectric substrate (e.g., internal quality factors, loss and kinetic inductance fractions), which are important for device design and performance.

Superconducting microwave resonators are of interest for detection of light, quantum computing applications and materials characterization. This work presents a detailed procedure for fabrication and characterization of superconducting microwave resonator scattering parameters.

超伝導共振器の作製と評価

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors ...

Solvent Bonding for Fabrication of PMMA and COP Microfluidic Devices

Thermoplastic microfluidic devices offer many advantages over those made from silicone elastomers, but bonding procedures must be developed for each thermoplastic of interest. Solvent bonding is a simple and versatile method that can be used to fabricate devices from a variety of plastics. An appropriate solvent is added between two device layers to be bonded, and heat and pressure are applied to the device to facilitate the bonding. By using an appropriate combination of solvent, plastic, heat, and pressure, the device can be sealed with a high quality bond, characterized as having high bond coverage, bond strength, optical clarity, durability over time, and low deformation or damage to microfeature geometry. We describe the procedure for bonding devices made from two popular thermoplastics, poly(methyl-methacrylate) (PMMA), and cyclo-olefin polymer (COP), as well as a variety of methods to characterize the quality of the resulting bonds, and strategies to troubleshoot low quality bonds. These methods can be used to develop new solvent bonding protocols for other plastic-solvent systems.

Solvent bonding is a simple and versatile method for fabricating thermoplastic microfluidic devices with high quality bonds. We describe a protocol to achieve strong, optically clear bonds in PMMA and COP microfluidic devices that preserve microfeature details, by a judicious combination of pressure, temperature, an appropriate solvent, and device geometry.

PMMAおよびCOPマイクロ流体デバイスの作製のための溶剤接着

Thermoplastic microfluidic devices offer many advantages over those made from silicone elastomers, but bonding procedures must be developed for each ...

Construction and Operation of a Light-driven Gold Nanorod Rotary Motor System

The possibility to generate and measure rotation and torque at the nanoscale is of fundamental interest to the study and application of biological and artificial nanomotors and may provide new routes towards single cell analysis, studies of non-equilibrium thermodynamics, and mechanical actuation of nanoscale systems. A facile way to drive rotation is to use focused circularly polarized laser light in optical tweezers. Using this approach, metallic nanoparticles can be operated as highly efficient scattering-driven rotary motors spinning at unprecedented rotation frequencies in water.
In this protocol, we outline the construction and operation of circularly-polarized optical tweezers for nanoparticle rotation and describe the instrumentation needed for recording the Brownian dynamics and Rayleigh scattering of the trapped particle. The rotational motion and the scattering spectra provides independent information on the properties of the nanoparticle and its immediate environment. The experimental platform has proven useful as a nanoscopic gauge of viscosity and local temperature, for tracking morphological changes of nanorods and molecular coatings, and as a transducer and probe of photothermal and thermodynamic processes.

Plasmonic gold nanorods can be trapped in liquids and rotated at kHz frequencies using circularly-polarized optical tweezers. Introducing tools for Brownian dynamics analysis and light scatteringspectroscopy leads to a powerful system for research and application in numerous fields of science.

金ナノロッドの光駆動ロータリー モーター システムの構築と運用

The possibility to generate and measure rotation and torque at the nanoscale is of fundamental interest to the study and application of biological and ...

Fabrication of Refractive-index-matched Devices for Biomedical Microfluidics

The use of microfluidic devices has emerged as a defining tool for biomedical applications. When combined with modern microscopy techniques, these devices can be implemented as part of a robust platform capable of making simultaneous complementary measurements. The primary challenge created by the combination of these two techniques is the mismatch in refractive index between the materials traditionally used to make microfluidic devices and the aqueous solutions typically used in biomedicine. This mismatch can create optical artifacts near the channel or device edges. One solution is to reduce the refractive index of the material used to fabricate the device by using a fluorinated polymer such as MY133-V2000 whose refractive index is similar to that of water (n = 1.33). Here, the construction of a microfluidic device made out of MY133-V2000 using soft lithography techniques is demonstrated, using O2 plasma in conjunction with an acrylic holder to increase the adhesion between the MY133-V2000 fabricated device and the polydimethylsiloxane (PDMS) substrate. The device is then tested by incubating it filled with cell culture media for 24 h to demonstrate the ability of the device to maintain cell culture conditions during the course of a typical imaging experiment. Finally, quantitative phase microscopy (QPM) is used to measure the distribution of mass within the live adherent cells in the microchannel. This way, the increased precision, enabled by fabricating the device from a low index of refraction polymer such as MY133-V2000 in lieu of traditional soft lithography materials such as PDMS, is demonstrated. Overall, this approach for fabricating microfluidic devices can be readily integrated into existing soft lithography workflows in order to reduce optical artifacts and increase measurement precision.

This protocol describes the fabrication of microfluidic devices from MY133-V2000 to eliminate artifacts that often arise in microchannels due to the mismatching refractive indices between microchannel structures and an aqueous solution. This protocol uses an acrylic holder to compress the encapsulated device, improving adhesion both chemically and mechanically.

生体の屈折率-屈折率整合素子の作製

The use of microfluidic devices has emerged as a defining tool for biomedical applications. When combined with modern microscopy techniques, these devices ...