This work was carried out in the framework of the project &#8220;MIRAGE,&#8221; funded by the European Commission within the FP7 program.

1. assistida-LIFT flip-chip Bonding NOTA: Existem três etapas envolvidas na realização dos conjuntos de chips flip-assistida-lift, a saber-micro-colisão dos substratos, utilizando a técnica LIFT, anexando os chips optoeletrônicos aos substratos colidido com thermo-compressão método de colagem flip-chip e finalmente encapsulamento dos conjuntos ligados. Cada uma dessas etapas é discutido nas seções a seguir: <ol><li> Micro-batendo usando LIFT: <ol><li> Para a preparação dos doadores, depositar uma película fina de material dador para um substrato de suporte transparente ao laser. Para esta experiência, evaporar um filme de espessura 200 nm em metal índio em cima do veículo de substrato de vidro com dimensões: 2 polegadas de diâmetro x 0,05 centímetros de espessura. NOTA: método de preparação Dador depende da fase do material dador de, por exemplo, utilizar pulverização catódica e evaporação para materiais dadores de fase sólida e spin-coating e médico-patins em linha para o dador de fase líquidas. </li><li> Para a preparação do receptor, utilizar substratos de vidro com dimensões de 5 x 5 x 0,07 centímetros 3 como os receptores. Pattern estes substratos com as almofadas de contacto metálicos para ligação do chip de OE e fan-out estruturas usando fotolitografia sondagem. Para esta experiência, padrão de 4 mm de espessura almofadas títulos Ni-Au e fan-out sondagem faixas sobre substratos recipiente de vidro. </li><li> Em seguida, coloque o doador em contato com o receptor e montar o conjunto de doador-receptor em um computador controlado fase de tradução XY. NOTA: Dependendo da fase do material dador (por exemplo, sólido (índio) ou líquido (tinta / pasta)) e a sua espessura, o dador e o receptor são os substratos colocados em uma separação óptima, que pode ser facilmente controlado (por exemplo, pela usando espaçadores metálicos). </li><li> Concentre-se o feixe de laser incidente na interface carrier-doador empregando uma lente objetiva de 160 milímetros de comprimento focal e digitalizar o feixe (20 um tamanho spot) em todo o substrat doadore para a transferência de micro-solavancos doadores no receptor bond-pads. Use uma fonte de laser de picossegundos de 355 nm de comprimento de onda e 12 de duração do pulso psec para levantar solavancos índio no receptor obrigacionistas-pads em uma fluência de 270 mJ / cm 2. Nota: As propriedades do laser, como a energia, não. de impulsos, a altura da lente da objectiva, as coordenadas da localização precisa sobre o substrato receptor para os micro-saliências impressão doadores e o padrão desejado para ser transferido com precisão são controlados por um programa de computador. Parâmetros experimentais-chave (por exemplo, a transferência de fluência) precisam ser otimizado em caso de utilização de outra fonte laser. </li><li> Para solavancos mais espessas mover o dador para um local fresco e repita o passo 1.1.4 várias vezes. Por exemplo, repita o passo 1.1.4 seis vezes para obter uma pilha de 6 solavancos índio impressos em cima uns dos outros para esta experiência. A final levantada solavancos têm uma altura média de ~ 1,5 mm e um diâmetro de 20 mm (Figura 2). NOTA: Para estas experimentos o perfil da superfície e da espessura dos solavancos foram medidos utilizando um perfilómetro óptico. Examinou-se que as colisões tinha uma morfologia convexa / cúpula com uma espessura média de 1,5 mm, em média diâmetro colisão (conforme marcado amarelo na Figura 3). A razão para isto é atribuída ao facto de o dador derretido na zona do laser irradiada e, em seguida, transferido o sedimento re-solidificado até alcançar a superfície do receptor (índio tem um baixo ponto de fusão). A vantagem disto é que ela resulta numa boa aderência da colisão impresso para as almofadas de contacto VCSEL. </li></ol></li><li> Chip para substrato de ligação thermo-compressão (Figuras 4-6): <ol><li> Use um bonder flip-chip de semi-automático para a colagem dos chips optoeletrônicos aos substratos batido. </li><li> Coloque o receptor colidido eo chip a ser colada em suas respectivas placas de vácuo do bonder. Coloque o chip em uma posição invertida, ou seja, com a sua área ativa facing para baixo. </li><li> Use uma ferramenta de captação adequados e alinhá-lo no centro do chip. Use uma ferramenta em forma de agulha, como mostrado na Figura 5. Em seguida, escolha o chip utilizando esta ferramenta pick-up. </li><li> Alinhe o chip Bond almofadas com as almofadas de contacto correspondentes no substrato receptor usando um sistema de câmera-alinhamento. </li><li> Uma vez alinhados lugar do chip no substrato. </li><li> Aplicar calor (~ 200 ° C) e pressão (12,5 gf / colisão) simultaneamente para realizar chip para substrato interligações eléctricas e mecânicas. </li></ol></li><li> Encapsulation das assembleias aduaneiros (Figuras 4-6): <ol><li> Dispensar um adesivo opticamente transparente em torno das bordas do conjunto de ligado utilizando uma agulha de seringa. O encapsulamento aumenta a confiabilidade mecânica dos conjuntos ligados. Use um único componente UV adesivo curável como NOA 86 para encapsular os chips ligados. </li><li> Curar o adesivo utilizando uma lâmpada de UV para ~ 30 seg. </li></ol></li></ol> 2. Caracterização dos Bonded Vertical-cavidade Lasers emissores de superfície (VCSELs) NOTA: Após fabrico o próximo passo é avaliar o desempenho electro-óptico dos conjuntos ligados. A luz-corrente-tensão (LIV) curvas dos dispositivos são registrados pós-ligação usando uma estação de sonda. As seguintes etapas estão envolvidas para o ensaio: <ol><li> Coloque o flip-chip dispositivo ligado para um palco transparente feito por encomenda. A fase tem um buraco perfurado no meio para fácil acesso para a luz emitida pelos VCSEL. </li><li> Coloque um fotodetector (PD) sob o palco transparente e alinhar a sua área ativa com o chip ligado usando um microscópio. </li><li> Precisamente posicionar as agulhas de sondagem sobre o Ni-Au almofadas sondagem utilizando um microscópio. </li><li> Injectar-se a 10 mA de corrente e medir a queda de tensão através do VCSEL e a luz emitida por ele utilizar uma unidade de fonte-medidor de corrente / tensão e um medidor de potência respectivamente. </li></ol>

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The authors have nothing to disclose.

Neste artigo, demonstramos thermo-compressão flip-chip de ligação de chips VCSEL únicos usando uma técnica de gravação direta a laser chamado LIFT. As etapas de fabrico envolvidas montagem impressão das micro-saliências de índio para as almofadas de contacto do substrato, utilizando a técnica de elevador. Isto foi seguido por termo-compressão flip-chip de ligação de fichas VCSEL aos substratos batido e, finalmente, a sua encapsulação. Confiabilidade elétrica, óptica e mecâ...

Induzida por laser Transferência Forward (LIFT) é um direct-escrever método de fabricação aditiva versátil para definição do padrão de etapa única e transferência de material com micron e sub-micron-resolução. Neste artigo, apresentamos o uso de LIFT como uma técnica de bater para embalagem flip-chip vertical-cavidade emissores de superfície lasers (VCSELs) em uma escala de chip. Flip-chip é uma tecnologia-chave na embalagem e integração de componentes eletrônicos e optoeletrônicos (OE) do sistema. A fim de alcançar a integração densa de componentes de ligação passo fino é essencial. Embora passo fino de ligação foi demonstrada por algumas das técnicas padrão, mas há um vazio em termos de combinação, em conjunto as outras características importantes, tais como a flexibilidade, a relação custo-eficácia, rapidez, precisão e baixo da temperatura de processamento. A fim de atender a esses requisitos demonstramos método de ligação assistida-LIFT thermo-compressão para colagem passo fino de componentes OE. Em LIFT, uma película fina de material a ser impresso (referido como o dador) é depositado sobre uma face de um substrato de suporte transparente ao laser (referido como transportador). A figura 1 ilustra o princípio básico desta técnica. Um pulso de laser incidente de intensidade suficiente é então focada na interface transportador-doador que proporciona a força de propulsão necessária para transmitir a transferir o pixel doador da zona irradiada para outro substrato (referido como o receptor) colocado em estreita proximidade. LIFT foi relatada pela primeira vez em 1986 por Bohandy como uma técnica para imprimir linhas de cobre micronizadas para a reparação de danos foto-máscaras 3. Desde a sua primeira demonstração desta técnica tem ganho grande interesse como uma tecnologia de fabricação de micro-nano para padronização de impressão e controlada de uma vasta gama de materiais, tais como cerâmica, nanotubos de carbono 4, 5 QDs 6, as células vivas 7, gráficoene 8, para diversas aplicações, tais como bio-sensores 9, OLEDs 10, componentes optoeletrônicos 11, sensores plasmonic 12, orgânico-electronics 13 e colagem 14,15 virar-chip. LIFT oferece diversas vantagens sobre os Batendo e técnicas de colagem flip-de chips existentes, tais como simplicidade, rapidez, flexibilidade, custo-eficácia, de alta resolução e precisão para embalagem flip-chip componentes OE.

<table><tbody><tr><td>Laser source</td><td>3D MicroMac (3DMM)</td><td>2912-295</td><td></td></tr><tr><td>Photodetector</td><td>Newport&amp;nbsp;</td><td>818 series</td><td></td></tr><tr><td>Source measurement unit</td><td>Keithley&amp;nbsp;</td><td>2401</td><td></td></tr><tr><td>Power meter</td><td>Newport&amp;nbsp;</td><td>1930</td><td></td></tr><tr><td>Underfill</td><td>Norlands</td><td>NOA 86</td><td></td></tr><tr><td>UV lamp</td><td>Omnicure</td><td>Series 1000 UV</td><td></td></tr><tr><td>Probe station</td><td>Cascade Microtech</td><td>model 42</td><td></td></tr><tr><td>Flip-chip bonder</td><td>Dr. Tresky</td><td>T-320 X</td><td></td></tr></tbody></table>

laser-induced forward transfer for flip-chip packaging of single dies

Flip-chip embalagem (FC) é uma tecnologia fundamental para a realização de alto desempenho, os circuitos de ultra-miniaturizado e de alta densidade na indústria de micro-eletrônica. Nesta técnica, o chip e / ou o substrato é batido e as duas são ligadas através destas saliências condutoras. Muitas técnicas batendo têm sido desenvolvidos e intensamente investigado desde a introdução da tecnologia de FC, em 1960, 1, como a impressão stencil, parafuso prisioneiro bumping, evaporação e electroless / galvanoplastia 2. Apesar do progresso que estes métodos que efectuou todos eles sofrem de uma ou mais do que um inconvenientes que precisam de ser tratadas, tais como custo, as etapas de processamento complexas, altas temperaturas de processamento, tempo de fabrico e mais importante, a falta de flexibilidade. Neste artigo, demonstramos uma colisão técnica simples e de baixo custo à base de laser formando conhecido como transferência para a frente induzida por laser (LIFT) 3. Usando a técnica ELEVADOR uma vasta gama de materiais de colisão pode be impresso em uma única etapa com grande flexibilidade, alta velocidade e precisão na RT. Além disso, permite que o LIFT bumping e colagem para baixo para chip de escala, o que é fundamental para a fabricação de circuitos ultra-miniatura.

A Figura 7 mostra uma curva típica LIV que foi registada a partir de um dos muitos flip-chip de aparas aglomeradas VCSEL. Um bom jogo entre a potência óptica de medição para o fornecedor citado valores indicados bom funcionamento do dispositivos vinculados pós-ligação. As curvas também foram registados ridade e pós-encapsulação e na comparação, verificou-se que o encapsulante não teve nenhum efeito sobre a funcionalidade do chip (como mostrado na Figura 7). Além disso, u...

Watch this Scientific Journal Video about Laser-induced Forward Transfer for Flip-chip Packaging of Single Dies at JoVE.com

Laser-induced Forward Transfer for Flip-chip Packaging of Single Dies

Nós demonstramos o uso da Transferência (LIFT) técnica Atacante induzida por laser para montagem flip-chip componentes optoeletrônicos. Esta abordagem fornece um, de baixo custo, baixa temperatura simples, solução rápida e flexível para o bem-pitch colidindo e colagem no chip de escala para a realização de circuitos de alta densidade para aplicações optoeletrônicos.

Transferência para a frente induzida por laser para Flip-chip Embalagem de matrizes de solteiro

Flip-chip (FC) packaging is a key technology for realizing high performance, ultra-miniaturized and high-density circuits in the micro-electronics ...

laser-induced-forward-transfer-for-flip-chip-packaging-of-single-dies

Research

JoVE Journal

Engineering

12.3K visualizações.  Ghent University-imec.  Nós demonstramos o uso da Transferência (LIFT) técnica Atacante induzida por laser para montagem flip-chip componentes optoeletrônicos. Esta abordagem fornece um, de baixo custo, baixa temperatura simples, solução rápida e flexível para o bem-pitch colidindo e colagem no chip de escala para a realização de circuitos de alta densidade para aplicações optoeletrônicos. 

Vídeo: Laser-induced Forward Transfer for Flip-chip Packaging of Single Dies

Lensless Fluorescent Microscopy on a Chip

On-chip lensless imaging in general aims to replace bulky lens-based optical microscopes with simpler and more compact designs, especially for high-throughput screening applications. This emerging technology platform has the potential to eliminate the need for bulky and/or costly optical components through the help of novel theories and digital reconstruction algorithms. Along the same lines, here we demonstrate an on-chip fluorescent microscopy modality that can achieve e.g., &lt;4&mu;m spatial resolution over an ultra-wide field-of-view (FOV) of &gt;0.6-8 cm2 without the use of any lenses, mechanical-scanning or thin-film based interference filters. In this technique, fluorescent excitation is achieved through a prism or hemispherical-glass interface illuminated by an incoherent source. After interacting with the entire object volume, this excitation light is rejected by total-internal-reflection (TIR) process that is occurring at the bottom of the sample micro-fluidic chip. The fluorescent emission from the excited objects is then collected by a fiber-optic faceplate or a taper and is delivered to an optoelectronic sensor array such as a charge-coupled-device (CCD). By using a compressive-sampling based decoding algorithm, the acquired lensfree raw fluorescent images of the sample can be rapidly processed to yield e.g., &lt;4&mu;m resolution over an FOV of &gt;0.6-8 cm2. Moreover, vertically stacked micro-channels that are separated by e.g., 50-100 &mu;m can also be successfully imaged using the same lensfree on-chip microscopy platform, which further increases the overall throughput of this modality. This compact on-chip fluorescent imaging platform, with a rapid compressive decoder behind it, could be rather valuable for high-throughput cytometry, rare-cell research and microarray-analysis.

A lensless on-chip fluorescent microscopy platform is demonstrated that can image fluorescent objects over an ultra-wide field-of-view of e.g., &#62;0.6-8 cm2 with &#60;4&#956;m resolution using a compressive sampling based decoding algorithm. Such a compact and wide-field fluorescent on-chip imaging modality could be valuable for high-throughput cytometry, rare-cell research and microarray-analysis.

Microscopia fluorescente sem lente em um Chip

On-chip lensless imaging in general aims to replace bulky lens-based optical microscopes with simpler and more compact designs, especially for ...

Bioengenharia

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

As mass-produced silicon transistors have reached the nano-scale, their behavior and performances are increasingly affected, and often deteriorated, by quantum mechanical effects such as tunneling through single dopants, scattering via interface defects, and discrete trap charge states. However, progress in silicon technology has shown that these phenomena can be harnessed and exploited for a new class of quantum-based electronics. Among others, multi-layer-gated silicon metal-oxide-semiconductor (MOS) technology can be used to control single charge or spin confined in electrostatically-defined quantum dots (QD). These QD-based devices are an excellent platform for quantum computing applications and, recently, it has been demonstrated that they can also be used as single-electron pumps, which are accurate sources of quantized current for metrological purposes. Here, we discuss in detail the fabrication protocol for silicon MOS QDs which is relevant to both quantum computing and quantum metrology applications. Moreover, we describe characterization methods to test the integrity of the devices after fabrication. Finally, we give a brief description of the measurement set-up used for charge pumping experiments and show representative results of electric current quantization.

The fabrication process and experimental characterization techniques relevant to single-electron pumps based on silicon metal-oxide-semiconductor quantum dots are discussed.

Silicon Metal-Óxido-semiconductor Quantum Dots para bombear-elétron único

As mass-produced silicon transistors have reached the nano-scale, their behavior and performances are increasingly affected, and often deteriorated, by ...

Engenharia

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data acquisition times with high spatial resolution. In the electronics industry there is serious interest in performing failure analysis on 3D microelectronic packages, many which contain multiple levels of high-density interconnections. Often in tomography there is a trade-off between image resolution and the volume of a sample that can be imaged. This inverse relationship limits the usefulness of conventional computed tomography (CT) systems since a microelectronic package is often large in cross sectional area 100-3,600 mm2, but has important features on the micron scale. The micro-tomography beamline at the Advanced Light Source (ALS), in Berkeley, CA USA, has a setup which is adaptable and can be tailored to a sample&#39;s properties, i.e., density, thickness, etc., with a maximum allowable cross-section of 36 x 36 mm. This setup also has the option of being either monochromatic in the energy range ~7-43 keV or operating with maximum flux in white light mode using a polychromatic beam. Presented here are details of the experimental steps taken to image an entire 16 x 16 mm system within a package, in order to obtain 3D images of the system with a spatial resolution of 8.7 &#181;m all within a scan time of less than 3 min. Also shown are results from packages scanned in different orientations and a sectioned package for higher resolution imaging. In contrast a conventional CT system would take hours to record data with potentially poorer resolution. Indeed, the ratio of field-of-view to throughput time is much higher when using the synchrotron radiation tomography setup. The description below of the experimental setup can be implemented and adapted for use with many other multi-materials.

For this study synchrotron radiation micro-tomography, a non-destructive three-dimensional imaging technique, is employed to investigate an entire microelectronic package with a cross-sectional area of 16 x 16 mm. Due to the synchrotron&#39;s high flux and brightness the sample was imaged in just 3 min&#160;with an 8.7 &#181;m spatial resolution.

Usando Synchrotron Radiation microtomografia para investigar Multi-escala Pacotes de microeletrônicos tridimensionais

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data ...

Laser-induced Forward Transfer of Ag Nanopaste

Over the past decade, there has been much development of non-lithographic methods1-3 for printing metallic inks or other functional materials. Many of these processes such as inkjet3 and laser-induced forward transfer (LIFT)4 have become increasingly popular as interest in printable electronics and maskless patterning has grown. These additive manufacturing processes are inexpensive, environmentally friendly, and well suited for rapid prototyping, when compared to more traditional semiconductor processing techniques. While most direct-write processes are confined to two-dimensional structures and cannot handle materials with high viscosity (particularly inkjet), LIFT can transcend both constraints if performed properly. Congruent transfer of three dimensional pixels (called voxels), also referred to as laser decal transfer (LDT)5-9, has recently been demonstrated with the LIFT technique using highly viscous Ag nanopastes to fabricate freestanding interconnects, complex voxel shapes, and high-aspect-ratio structures. In this paper, we demonstrate a simple yet versatile process for fabricating a variety of micro- and macroscale Ag structures. Structures include simple shapes for patterning electrical contacts, bridging and cantilever structures, high-aspect-ratio structures, and single-shot, large area transfers using a commercial digital micromirror device (DMD) chip.

We demonstrate the use of the Laser-induced forward transfer technique (LIFT) for the printing of high-viscosity Ag paste. This technique offers a simple, low temperature, robust process for non-lithographically printing microscale 2D and 3D structures.

Transferência Atacante induzida por laser de Ag Nanopasta

Over the past decade, there has been much development of non-lithographic methods1-3 for printing metallic inks or other functional materials. Many of ...

Plasmonic Trapping and Release of Nanoparticles in a Monitoring Environment

Plasmonic tweezers use surface plasmon polaritons to confine polarizable nanoscale objects. Among the various designs of plasmonic tweezers, only a few can observe immobilized particles. Moreover, a limited number of studies have experimentally measured the exertable forces on the particles. The designs can be classified as the protruding nanodisk type or the suppressed nanohole type. For the latter, microscopic observation is extremely challenging. In this paper, a new plasmonic tweezer system is introduced to monitor particles, both in directions parallel and orthogonal to the symmetric axis of a plasmonic nanohole structure. This feature enables us to observe the movement of each particle near the rim of the nanohole. Furthermore, we can quantitatively estimate the maximal trapping forces using a new fluidic channel.

A microchip fabrication process that incorporates plasmonic tweezers is presented here. The microchip enables the imaging of a trapped particle to measure maximal trapping forces.

Plasmonic captura e liberação de nanopartículas em um ambiente de Monitoramento

Plasmonic tweezers use surface plasmon polaritons to confine polarizable nanoscale objects. Among the various designs of plasmonic tweezers, only a few ...

Multicolor Fluorescence Detection for Droplet Microfluidics Using Optical Fibers

Fluorescence assays are the most common readouts used in droplet microfluidics due to their bright signals and fast time response. Applications such as multiplex assays, enzyme evolution, and molecular biology enhanced cell sorting require the detection of two or more colors of fluorescence. Standard multicolor detection systems that couple free space lasers to epifluorescence microscopes are bulky, expensive, and difficult to maintain. In this paper, we describe a scheme to perform multicolor detection by exciting discrete regions of a microfluidic channel with lasers coupled to optical fibers. Emitted light is collected by an optical fiber coupled to a single photodetector. Because the excitation occurs at different spatial locations, the identity of emitted light can be encoded as a temporal shift, eliminating the need for more complicated light filtering schemes. The system has been used to detect droplet populations containing four unique combinations of dyes and to detect sub-nanomolar concentrations of fluorescein.

Multicolor fluorescence detection in droplet microfluidics typically involves bulky and complex epifluorescence microscope-based detection systems. Here we describe a compact and modular multicolor detection scheme that utilizes an array of optical fibers to temporally encode multicolor data collected by a single photodetector.

Multicolor detecção de fluorescência para Gota microfluídica Utilizando Fibras Ópticas

Fluorescence assays are the most common readouts used in droplet microfluidics due to their bright signals and fast time response. Applications such as ...

Automated Delivery of Microfabricated Targets for Intense Laser Irradiation Experiments

Described is an experimental procedure that enables high-power laser irradiation of microfabricated targets. Targets are brought to the laser focus by a closed feedback loop that operates between the target manipulator and a ranging sensor. The target fabrication process is explained in detail. Representative results of MeV-level proton beams generated by irradiation of 600 nm thick gold foils at a rate of 0.2 Hz are given. The method is compared with other replenishable target systems and the prospects of increasing the shot rates to above 10 Hz are discussed.

A protocol is presented for automated irradiation of thin gold foils with high intensity laser pulses. The protocol includes a step-by-step description of the micromachining target fabrication process and a detailed guide for how targets are brought to the laser&#39;s focus at a rate of 0.2 Hz.

Entrega automatizada de alvos microfabricados para experimentos intensos de irradiação a laser

Described is an experimental procedure that enables high-power laser irradiation of microfabricated targets. Targets are brought to the laser focus by a ...

Multi-step Variable Height Photolithography for Valved Multilayer Microfluidic Devices

Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to entry for non-specialists who would benefit greatly from the ability to develop their own microfluidic devices to address research questions. Particularly lacking has been the open dissemination of protocols related to photolithography, a key step in the development of a replica mold for the manufacture of polydimethylsiloxane (PDMS) devices. While the fabrication of single height silicon masters has been explored extensively in literature, fabrication steps for more complicated photolithography features necessary for many interesting device functionalities (such as feature rounding to make valve structures, multi-height single-mold patterning, or high aspect ratio definition) are often not explicitly outlined. 
Here, we provide a complete protocol for making multilayer microfluidic devices with valves and complex multi-height geometries, tunable for any application. These fabrication procedures are presented in the context of a microfluidic hydrogel bead synthesizer and demonstrate the production of droplets containing polyethylene glycol (PEG diacrylate) and a photoinitiator that can be polymerized into solid beads. This protocol and accompanying discussion provide a foundation of design principles and fabrication methods that enables development of a wide variety of microfluidic devices. The details included here should allow non-specialists to design and fabricate novel devices, thereby bringing a host of recently developed technologies to their most exciting applications in biological laboratories.

Multilayer microfluidic devices often involve the fabrication of master molds with complex geometries for functionality. This article presents a complete protocol for multi-step photolithography with valves and variable height features tunable to any application. As a demonstration, we fabricate a microfluidic droplet generator capable of producing hydrogel beads.

Multi-passo fotolitografia Variável Altura para Valved multicamada microfluídicos Devices

Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to ...

High-resolution Volume Imaging of Neurons by the Use of Fluorescence eXclusion Method and Dedicated Microfluidic Devices

Volume is an important parameter regarding physiological and pathological characteristics of neurons at different time scales. Neurons are quite unique cells regarding their extended ramified morphologies and consequently raise several methodological challenges for volume measurement. In the particular case of in vitro neuronal growth, the chosen methodology should include sub-micrometric axial resolution combined with full-field observation on time scales from minutes to hours or days. Unlike other methods like cell shape reconstruction using confocal imaging, electrically-based measurements or Atomic Force Microscopy, the recently developed Fluorescence eXclusion method (FXm) has the potential to fulfill these challenges. However, although being simple in its principle, implementation of a high-resolution FXm for neurons requires multiple adjustments and a dedicated methodology. We present here a method based on the combination of fluorescence exclusion, low-roughness multi-compartments microfluidic devices, and finally micropatterning to achieve in vitro measurements of local neuronal volume. The high resolution provided by the device allowed us to measure the local volume of neuronal processes (neurites) and the volume of some specific structures involved in neuronal growth, such as growth cones (GCs).

Volume is an important parameter regarding physiological and pathological characteristics of cells. We describe a fluorescent exclusion method allowing full-field measurement of in vitro neuronal volume with sub-micrometric axial resolution required for the analysis of neurites and dynamic structures implied in neuronal growth.

De alta resolução Volume Imaging de neurônios pela exclusão da utilização da fluorescência método e dedicado Microfluidic dispositivos

Volume is an important parameter regarding physiological and pathological characteristics of neurons at different time scales. Neurons are quite unique ...

Neurociência

Microfabrication of Implantable Optics Integrated in a Microstructured Imaging Window for Advanced In Vivo Imaging

In the context of biomaterials and drug testing in animal models, this study presents a streamlined protocol for fabricating a novel implantable integrated imaging window. The micro-device comprises a sophisticated system of microlenses coupled with micro-scaffolds specifically designed for in vivo quantification of the immune response using advanced non-linear excitation microscopy. The protocol is based on two-photon polymerization (2PP) of the biocompatible photoresist SZ2080, which enables the fabrication of micro-scaffolds and micro-lenses in a continuous sequence to enhance manufacturing efficiency and precision. To further improve speed, accuracy, and structural integrity, a hybrid optics fabrication approach was implemented, involving the 2PP of the microlens outer shell followed by UV bulk crosslinking of the inner core. This innovative technique optimizes the optical properties of the microlenses while streamlining the production process. The resulting micro-device demonstrates high reproducibility and mechanical stability, making it an effective method for prototyping microscale optical systems for a range of biomedical applications.

This protocol describes the fabrication of an implantable integrated imaging window using 3D laser printing. The window consists of a system of microlenses coupled with micro-scaffolds. The method involves two-photon polymerization (2PP) of the biocompatible photoresist SZ2080 in a continuous sequence, optimizing manufacturing efficiency and alignment between the different components.