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Publications de l'équipe MEMS

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18342
09/11/2018

Optomechanical Resonating Probe for Very High Speed Sensing of Atomic Forces

P.ALLAIN, L.SCHWAB, C.MISNER, M.GELY, E.MAIRIAUX, M.HERMOUET, B.WALTER, G.LEO, S.HENTZ, M.FAUCHER, G.JOURDAN, B.LEGRAND, I.FAVERO

MPQ, MEMS, IEMN, CEA-LETI, VMICRO Sas, Paris Diderot, IEMN Villeneuve

Rapport LAAS N°18342, Novembre 2018, 14p.

Lien : https://hal.laas.fr/hal-01908683

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Abstract

Atomic force spectroscopy and microscopy (AFM) are invaluable tools to characterize nanostructures and biological systems . Most experiments, including state -­‐ of -­‐ the -­‐ art images of molecular bonds, are achieved by driving probe s at their mechanical resonance . This resonance reaches the MHz for the fastest AFM micro -­‐ cantilevers , with typical motion amplitude of a few nanomet re s . Next -­‐ generation investigation s of molecular scale dynamics, including faster force imaging and high er -­‐ resolution spectroscopy of dissipative interactions, require more bandwidth and vibration amplitude s below in t er atomic distance , for non -­‐ pertu r bative short -­‐ range tip -­‐ matter interactions . Probe frequency is a key parameter to improve bandwidth while reducing Brownian motion , allowing large signal -­‐ to -­‐ noise for exquisite resolution . O ptomechanical resonators reach motion detection at 10 -­‐ 18 m.Hz -­‐ 1/2 , while coupling light to bulk vibration modes whose frequencies largely surpass those of cantilevers . Here we introduce a n optically operated resonating optomechanical atomic force probe of frequency 2 decades above the fastest functional AFM cantilevers while Brownian motion is 4 orders below. B ased on a Silicon -­‐ On -­‐ Insulator technology, the probe demonstrates high -­‐ speed sensing of contact and non -­‐ contact interactions with sub -­‐ picomet r e driven motion, breaking open current locks for faster and finer atomic force spectroscopy .

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18341
26/10/2018

MEMS-based atomic force microscopy probes: from electromechanical to optomechanical vibrating sensors

B.LEGRAND, L.SCHWAB, P.ALLAIN, I.FAVERO, M.FAUCHER, D.THERON, B.WALTER, J.P.SALVETAT, S.HENTZ, G.JOURDAN

MEMS, MPQ, Paris Diderot, IEMN Villeneuve, VMICRO Sas, CRPP, Pessac, CEA-LETI

Manifestation avec acte : AVS International Symposium & Exhibition ( AVS ) 2018 du 21 octobre au 26 octobre 2018, Long Beach (USA), Octobre 2018 , N° 18341

Lien : https://hal.laas.fr/hal-01908666

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Abstract

Scanning probe microscopy has been one of the most important instrumental discoveries during the last quarter of the last century. In particular, atomic force microscopy (AFM) is a cross-disciplinary technique able to provide sample morphology down to the atomic scale. It offers invaluable tools to support the development of nano-sciences, information technologies, micro-nanotechnologies and nano-biology. For more than 20 years, boosting the scan rate of AFM has been an increasingly important challenge of the community. However still today, performing routine and user-friendly AFM experiments at video rate remains unreachable in most cases. The conventional AFM probe based on a micro-sized vibrating cantilever is the major obstacle in terms of bandwidth and resonance frequency. Following a brief description of the context of the work, the talk will first describe the development of AFM probes based on MEMS devices that make use of ring-shaped microresonators vibrating above 10 MHz. A focus will be dedicated to the electrical detection scheme. Based on capacitive transduction and microwave reflectometry, it achieves a displacement resolution of 1E-15 m/√Hz, allowing the measurement of the thermomechanical vibration of the MEMS AFM probes in air. Imaging capability obtained on DNA origamis samples at a frame rate greater than 1 image/s will be shown as well as investigation of block copolymer surfaces to elucidate the tip-surface interaction when vibration amplitudes are lower than 100 pm. In the following, our recent research direction at the convergence of the fields of micro/nanosystems and VLSI optomechanics on silicon chips will be presented. Optomechanical resonators allow indeed overcoming the resolution limitation imposed by usual electromechanical transduction schemes. Here, we will introduce fully optically driven and sensed optomechanical AFM probes which resonance frequency is above 100 MHz and Brownian motion below 1E-16 m/√Hz, paving the way for high-Speed AFM operation with exquisite resolutions at sub-angstrom vibration amplitudes.

145035
18327
12/10/2018

Développement d'un système autonome de détection et de quanti-cation des microARNs avec une plateforme nano/uidique pour la prise en charge du cancer du pancréas

J.CACHEUX

MEMS

Doctorat : Université de Toulouse III - Paul Sabatier, 12 Octobre 2018, 193p., Président: L.BUSCAIL, Rapporteurs: E.DELAMARCHE, I.VAN SEUNINGEN, Examinateurs: A.CARRIER, Directeurs de thèse: P.CORDELIER, T.LEICHLE , N° 18327

Lien : https://hal.laas.fr/tel-01922268

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Abstract

85% of patients affected by pancreatic adenocarcinoma (PDA) are diagnosed at an advanced stage, preventing effective care and curative treatments. Therefore, it is urgent to identify reliable biomarkers for the early detection of disease status, including relapse. MiRNAs (micro ribonucleic acids) are biomarkers of PDA, with demonstrated clinical value for early detection of tumors and monitoring of response to treatment. However, current methods of extraction and detection of miRNA are not compatible with clinical use. New technologies derived from micro and nanofabrication methods have the potential to facilitate the implementation of diagnostic tests, by offering a high degree of portability and robustness, short time to results at low cost. Here, we propose a nanofluidic platform coupled to fluorescence detection for the real time measurement of molecular interactions in a confined environment. We first describe the detection platform via a one-dimension theoretical model based on molecular dynamics to predict the capture of miRNAs into biofunctionalized nanochannels. The originality of the system lies in the non-homogeneous hybridization of miRNA targets onto the sensor. We demonstrate that the analysis of the spatial hybridization profile enables the determination of the affinity of the captured miRNA with the probe sequence in a wash-free single step. We then show the rapid discrimination (less than 10 minutes) of single nucleotide difference (SND) using this strategy. The performance of the device in the context of pancreatic cancer detection is discussed: the effect of sample preparation of complex biofluids is studied and two labeling approaches compatible with the detection of endogenous miRNAs are described and compared, leading to the detection of miRNAs extracted from model cell cultures of pancreatic cancer.

Résumé

85% des patients atteints de cancer du pancréas présentent au diagnostic des formes avancées de la maladie qui empêchent leur prise en charge thérapeutique efficace. Il est donc urgent de mettre en évidence des marqueurs diagnostics permettant de détecter plus tôt ces cancers, mais également leur rechute, afin d’améliorer leur prise en charge. Les miARNs (micro acides ribonucléiques) sont des biomarqueurs du cancer du pancréas, présentant une valeur clinique démontrée pour la détection précoce des tumeurs et le suivi de la réponse au traitement. Cependant, les méthodes actuelles d’extraction et de détection de ces molécules ne sont pas adaptées à une utilisation clinique. Les nouvelles technologies issues des méthodes de micro et nanofabrication ont le potentiel de permettre la mise en place de tests diagnostiques, offrant un haut degré de portabilité et de robustesse, une lecture en temps réel, et à bas coût. Nous proposons ici une plateforme nanofluidique couplée à une détection en fluorescence permettant la mesure en temps réel d’interactions moléculaires en milieu hyper-confiné. Nous décrivons dans un premier temps la plateforme de détection via un modèle théorique à une dimension basé sur la dynamique moléculaire permettant de prédire la capture spécifique des miARNs dans un nanocanal fonctionnalisé. L’originalité du système réside dans une accroche non homogène des miARNs sur la surface du capteur. Ainsi, nous démontrons que l’étude du profil spatial d’hybridation engendré permet de déterminer l’affinité du miARN capturé avec la séquence sonde en une seule étape, sans lavage. Nous démontrons également l’excellente spécificité du biocapteur qui permet la discrimination rapide (moins de 10 minutes) de SND (single nucleotide difference). Les performances du dispositif pour des applications au plus près des problématiques biologiques dans le cadre de la détection du cancer du pancréas sont enfin discutées : les effets de la préparation d’échantillon types biofluides complexes sur l’extraction de miARNs sont étudiés, puis deux approches permettant la détection de miARNs endogènes sont décrites et comparées, conduisant à la détection de miARNs extraits de cultures cellulaires modèles du cancer du pancréas.

Mots-Clés / Keywords
Cancer du pancréas; microARNs; Nanofluidique; Microscopie en fluorescence; Pancreactic cancer; Nanofluidics; Fluorescence microscopy;

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18283
01/08/2018

Direct laser fabrication of meso-scale 2D and 3D architectures with micrometric feature resolution

A.ACCARDO, R.COURSON, R.RIESCO ALVAREZ, V.RAIMBAULT, L.MALAQUIN

ELIA, TEAM, MEMS, MICA

Revue Scientifique : Additive Manufacturing, Vol.22, pp.440-446, Août 2018 , N° 18283

Lien : https://hal.laas.fr/hal-01875364

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Abstract

The realization of 2D and 3D meso-scale architectures is an area of research involving a wide range of disciplines ranging from materials science, microelectronics, phononics, microfluidics to biomedicine requiring millimeter to centimeter-sized objects embedding micrometric features. In the recent years, several technologies have been employed to provide optimal features in terms of object size flexibility, printing resolution, large materials library and fabrication speed. In this work, we report a fully customizable single-photon absorption 3D fabrication methodology based on direct laser fabrication. To validate this approach and highlight the versatility of the setup, we have fabricated a comprehensive ensemble of 2D and 3D designs with potential applications in biomimetics, 3D scaffolding and microfluidics. The high degree of tunability of the reported fabrication system allows tailoring the laser power, slicing and fabrication speed for each single area of the design. These unique features enable a rapid prototyping of millimeter to centimeter-sized objects involving 3D architectures with true freestanding subunits and micrometric feature reproducibility. The presented strategy fills indeed the current technological gap related to the development of meso-scale architectures required in multidisciplinary fields of research.

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18167
01/07/2018

Micromachining-Compatible, Facile Fabrication of Polymer Nanocomposite Spin Crossover Actuators

M.DMANRIQUE JUAREZ, F.MATHIEU, A.LABORDE, S.RAT, V.SHALABAEVA, P.DEMONT, O.THOMAS, L.SALMON, T.LEICHLE, L.NICU, G.MOLNAR, A.BOUSSEKSOU

MEMS, I2C, TEAM, LCC, CIRIMAT, LSIS, ENSAM, Lille

Revue Scientifique : Advanced Functional Materials, Vol.28, N°29, Juillet 2018, DOI 10.1002/adfm.201801970 , N° 18167

Lien : https://hal.laas.fr/hal-01816709

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Abstract

[Fe II (Htrz) 2 (trz)](BF 4) spin crossover particles of 85 nm mean size were dispersed in an SU-8 polymer matrix and spray-coated onto silicon microcantilevers. The subsequent photo-thermal treatment of the polymer resist led to micrometer thick, smooth and homogeneous coatings, which exhibited well-reproducible actuation upon the thermally-induced spin transition. The actuation amplitude as a function of temperature was accurately determined by combining an integrated piezoresisitive detection with external optical interferometry, which allowed for the assessment of the associated actuation force (9.4 mN), stress (28 MPa), strain (1.0 %) and work density (140 mJ/cm 3) through a stratified beam model. The dynamical mechanical characterization of the films evidenced an increase of the resonance frequency and a concomitant decrease of the damping in the high temperature phase, which arise due to a combined effect of the thickness and mechanical property changes. The spray-coating approach was also successfully extended to scale up the actuators for the cm-range on a polymer substrate providing perspectives for biomimetic soft actuators.

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18168
05/06/2018

Self-Aligned Functionalization Approach to Order Neuronal Networks at the Single-Cell Level

A.CASANOVA, MC.BLATCHE, C.FERRE, H.MARTIN, D.GONZALES DUNIA, L.NICU, G.LARRIEU

MPN, I2C, INSERM, MEMS

Revue Scientifique : Langmuir, Vol.34, N°22, pp.6612-6620, Juin 2018 , N° 18168

Lien : https://hal.laas.fr/hal-01816434

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Despite significant progress, our knowledge of the functioning of the central nervous system still remains scarce to date. A better understanding of its behavior, in either normal or diseased conditions, goes through an increased knowledge of basic mechanisms involved in neuronal function, including at the single-cell level. This has motivated significant efforts for the development of miniaturized sensing devices to monitor neuronal activity with high spatial and signal resolution. One of the main challenges remaining to be addressed in this domain is, however, the ability to create in vitro spatially ordered neuronal networks at low density with a precise control of the cell location to ensure proper monitoring of the activity of a defined set of neurons. Here, we present a novel self-aligned chemical functionalization method, based on a repellant surface with patterned attractive areas, which permits the elaboration of low-density neuronal network down to individual cells with a high control of the soma location and axonal growth. This approach is compatible with complementary metal-oxide–semiconductor line technology at a wafer scale and allows performing the cell culture on packaged chip outside microelectronics facilities. Rat cortical neurons were cultured on such patterned surfaces for over one month and displayed a very high degree of organization in large networks. Indeed, more than 90% of the network nodes were settled by a soma and 100% of the connecting lines were occupied by a neurite, with a very good selectivity (low parasitic cell connections). After optimization, networks composed of 75% of unicellular nodes were obtained, together with a control at the micron scale of the location of the somas. Finally, we demonstrated that the dendritic neuronal growth was guided by the surface functionalization, even when micrometer scale topologies were encountered and we succeeded to control the extension growth along one-dimensional-aligned nanostructures with sub-micrometrical scale precision. This novel approach now opens the way for precise monitoring of neuronal network activity at the single-cell level.

143896
18117
01/06/2018

A review on mechanical considerations for chronically-implanted neural probes

C.BERGAUD, A.LECOMTE, E.DESCAMPS

MEMS, MICA

Revue Scientifique : Journal of Neural Engineering, Vol.15, N°3, Juin 2018 , N° 18117

Lien : https://hal.laas.fr/hal-01764292

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Abstract

This review intends to present a comprehensive analysis of the mechanical considerations for chronically-implanted neural probes. Failure of neural electrical recordings or stimulation over time has shown to arise from foreign body reaction and device material stability. It seems that devices that match most closely with the mechanical properties of the brain would be more likely to reduce the mechanical stress at the probe/tissue interface, thus improving body acceptance. The use of low Young's modulus polymers instead of hard substrates is one way to enhance this mechanical mimetism, though compliance can be achieved through a variety of means. The reduction of probe width and thickness in comparison to a designated length, the use of soft hydrogel coatings and the release in device tethering to the skull, can also improve device compliance. Paradoxically, the more compliant the device, the more likely it will fail during the insertion process in the brain. Strategies have multiplied this past decade to offer partial or temporary stiffness to the device to overcome this buckling effect. A detailed description of the probe insertion mechanisms is provided to analyze potential sources of implantation failure and the need for a mechanically-enhancing structure. This leads us to present an overview of the strategies that have been put in place over the last ten years to overcome buckling issues. Particularly, great emphasis is put on bioresorbable polymers and their assessment for neural applications. Finally, a discussion is provided on some of the key features for the design of mechanically-reliable, polymer-based next generation of chronic neuroprosthetic devices.

143461
18360
01/05/2018

Interfacial Rheology and Heterogeneity of Aging Asphaltene Layers at the Water–Oil Interface

C.C.CHANG, A.NOWBAHAR, V.MANSARD, I.WILLIAMS, J.MECCA, A.K.SCHMITT, T.H.KALANTAR, T.C.KUO, T.SQUIRES

Univ. of California, MEMS, The Dow Chemical

Revue Scientifique : Langmuir, Vol.34, N°19, pp.5409-5415, Mai 2018 , N° 18360

Lien : https://hal.archives-ouvertes.fr/hal-01920333

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Surface-active asphaltene molecules are naturally found in crude oil, causing serious problems in the petroleum industry by stabilizing emulsion drops, thus hindering the separation of water and oil. Asphaltenes can adsorb at water–oil interfaces to form viscoelastic interfacial films that retard or prevent coalescence. Here, we measure the evolving interfacial shear rheology of water–oil interfaces as asphaltenes adsorb. Generally, interfaces stiffen with time, and the response crosses over from viscous-dominated to elastic-dominated. However, significant variations in the stiffness evolution are observed in putatively identical experiments. Direct visualization of the interfacial strain field reveals significant heterogeneities within each evolving film, which appear to be an inherent feature of the asphaltene interfaces. Our results reveal the adsorption process and aged interfacial structure to be more complex than that previously described. The complexities likely impact the coalescence of asphaltene-stabilized droplets, and suggest new challenges in destabilizing crude oil emulsions.

145126
18096
01/03/2018

Spatial Analysis of Nanofluidic-Embedded Biosensors for Wash-Free Single-Nucleotide Difference Discrimination

J.CACHEUX, M.BRUT, A.BANCAUD, P.CORDELIER, T.LEICHLE

MEMS, M3, MILE, CRCT-INSERM

Revue Scientifique : ACS Sensors, Vol.3, N°3, pp.606-611, Mars 2018 , N° 18096

Lien : https://hal.laas.fr/hal-01762631

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In this work, we demonstrate that the analysis of spatially resolved nanofluidic-embedded biosensors permits the fast and direct discrimination of single-nucleotide difference (SND) within oligonucleotide sequences in a single step interaction. We design a sensor with a linear dimension much larger than the channel depth in order to ensure that the reaction over the whole sensor is limited by the convection rate. Thus, the targets are fully collected, inducing a nonuniform spatial hybridization profile. We also use the nanoscale height of the channel, which enables us to minimize the amount of labeled molecules flowing over the sensor and hence to reduce the fluorescence background, to carry out real-time hybridization detection by fluorescence microscopy. Taken together, these design rules allow us to show that the spatial hybridization profile depends on the duplex affinity, and we speculate that the on and off-rate constants can be inferred during target injection, which is not possible in local analysis where the dissociation step through rinsing must be conducted. We finally manage to discriminate a GT mismatch on a microRNA sequence by optimizing the interaction temperature and the probe design after a few minutes of interaction in a single step protocol. This work may be applied to any biosensing transduction scheme with spatial resolution, e.g., surface plasmon resonance imaging, integrated into nanofluidic channels for applications where high oligonucleotide sequence selectivity and short analysis times are required.

143275
18070
01/02/2018

Measuring Interfacial Polymerization Kinetics Using Microfluidic Interferometry

A.NOWBAHAR, V.MANSARD, J.MECCA, T.ARROWOOD, T.SQUIRES

Univ. of California, MEMS, The Dow Chemical

Revue Scientifique : Journal of the American Chemical Society, Vol.140, N°9, pp.3173-3176, Février 2018 , N° 18070

Lien : https://hal.archives-ouvertes.fr/hal-01734561

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Interfacial polymerization is used in a range of elds, both academic and industrial, for the production of bers, capsules , and lms. Despite its widespread use, measuring the reaction kinetics of interfacial polymerization has remained a challenge. For example, reaction kinetics for polyamide reverse osmosis membranes are dicult to obtain and rarely reported due to the thinness of lms, and rapidity of their formation at the liquid-liquid interface. Here, polyamide lm formation is studied using a microuidic, interferometry-based technique to measure monomer concentration near the interface as the reaction occurs. Our results are consistent with a polymeriza-tion reaction that is initially controlled by a reaction-diusion boundary layer within the organic phase. Using simple scaling arguments to analyze our data, we report the rst measurements of the reaction rate constant for this system.

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