Arrasate / Mondragón, Spain
Arrasate / Mondragón, Spain

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Altuna A.,Ikerlan S. Coop. | Menendez de la Prida L.,Instituto Cajal | Bellistri E.,Instituto Cajal | Gabriel G.,Institute Microelectronica Of Barcelona Imb Cnm | And 8 more authors.
Biosensors and Bioelectronics | Year: 2012

Here, we describe new fabrication methods aimed to integrate planar tetrode-like electrodes into a polymer SU-8 based microprobe for neuronal recording applications. New concepts on the fabrication sequences are introduced in order to eliminate the typical electrode-tissue gap associated to the passivation layer. Optimization of the photolithography technique and high step coverage of the sputtering process have been critical steps in this new fabrication process. Impedance characterization confirmed the viability of the electrodes for reliable neuronal recordings with values comparable to commercial probes. Furthermore, a homogeneous sensing behavior was obtained in all the electrodes of each probe. Finally, . in vivo action potential and local field potential recordings were successfully obtained from the rat dorsal hippocampus. Peak-to-peak amplitude of action potentials ranged from noise level to up to 400-500. μV. Moreover, action potentials of different amplitudes and shapes were recorded from all the four recording sites, suggesting improved capability of the tetrode to distinguish from different neuronal sources. © 2012 Elsevier B.V.


Altuna A.,Ikerlan S. Coop. | Gabriel G.,Institute Microelectronica Of Barcelona Imb Cnm | Gabriel G.,CIBER ISCIII | De La Prida L.M.,Instituto Cajal | And 7 more authors.
Journal of Micromechanics and Microengineering | Year: 2010

This paper presents novel design, fabrication, packaging and the first in vitro neural activity recordings of SU-8-based microneedles. The polymer SU-8 was chosen because it provides excellent features for the fabrication of flexible and thin probes. A microprobe was designed in order to allow a clean insertion and to minimize the damage caused to neural tissue during in vitro applications. In addition, a tetrode is patterned at the tip of the needle to obtain fine-scale measurements of small neuronal populations within a radius of 100 μm. Impedance characterization of the electrodes has been carried out to demonstrate their viability for neural recording. Finally, probes are inserted into 400 μm thick hippocampal slices, and simultaneous action potentials with peak-to-peak amplitudes of 200-250 μV are detected. © 2010 IOP Publishing Ltd.


Altuna A.,Ikerlan S. Coop. | Bellistri E.,Instituto Cajal | Cid E.,Instituto Cajal | Aivar P.,Instituto Cajal | And 12 more authors.
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2013

While novel influential concepts in neuroscience bring the focus to local activities generated within a few tens of cubic micrometers in the brain, we are still devoid of appropriate tools to record and manipulate pharmacologically neuronal activity at this fine scale. Here we designed, fabricated and encapsulated microprobes for simultaneous depth recording and drug delivery using exclusively the polymer SU-8 as structural material. A tetrode- and linear-like electrode patterning was combined for the first time with single and double fluidic microchannels for independent drug delivery. The device was tested experimentally using the in vivo anesthetized rat preparation. Both probe types successfully recorded detailed spatiotemporal features of local field potentials and single-cell activity at a resolution never attained before with integrated fluidic probes. Drug delivery was achieved with high spatial and temporal precision in a range from tens of nanoliters to a few microliters, as confirmed histologically. These technological advancements will foster a wide range of neural applications aimed at simultaneous monitoring of brain activity and delivery at a very precise micrometer scale. This journal is © 2013 The Royal Society of Chemistry.


Ajuria J.,Ikerlan S. Coop | Etxebarria I.,Ikerlan S. Coop | Cambarau W.,Ikerlan S. Coop | Munecas U.,Ikerlan S. Coop | And 3 more authors.
Energy and Environmental Science | Year: 2011

We report organic photovoltaic devices in which the standard ITO transparent electric contact has been substituted by lower cost ultrathin metallic electrodes. Solution and vacuum processable n and p-type semiconductors provide the electrode with the rectifying behavior of the diode. We are in this way able to invert the built-in electric field at wish and make the device deliberately either top or bottom sensitive with the same efficiency depending on the application. Taking advantage of these new generation electrodes we furthermore report devices with fill factors over 70% - to our knowledge, the largest published to date for an organic photovoltaic cell - and power conversion efficiencies over the state-of-art with 3.5% in inverted P3HT:PCBM devices, ITO free designs over 2.5% and (semi)transparent photovoltaic devices with conversion efficiencies close to 2.6%. This breakthrough could once and for all trigger the fabrication of organic tandem solar cells and photovoltaic windows. © 2011 The Royal Society of Chemistry.


Salgado O.,Ikerlan S. Coop. | Altuzarra O.,University of the Basque Country | Viadero F.,University of Cantabria | Hernandez A.,University of the Basque Country
Engineering Computations (Swansea, Wales) | Year: 2010

Purpose - The purpose of this paper is to provide a general approach to compute, determine, and characterize the connectivity of the end-effector of a robotic manipulator of arbitrary architecture, in any of the postures that it can reach. Design/methodology/approach - The types of motion of this link, i.e. translational, screw motions, combinations thereof, and self-motions, are first defined and determined, simplifying the understanding of the instantaneous behaviour of the manipulator, aided by the definition of an alternative input basis. Findings - The characterization provided by this paper simplifies the understanding of the instantaneous behaviour of the manipulator. The mobility of the end-effector is completely characterized by the principal screws of its motion, which can be obtained from a generalized eigenproblem. In the process, alternative demonstrations of well-known properties of the principal screws are provided. Research limitations/implications - The approach presented is focused on the kinetostatic analysis of manipulators, and therefore, subjected to rigid body assumption. Practical implications - This paper proposes effective approaches for engineering analysis of robotic manipulators. Originality/value - This approach is based on a pure theoretical kinematic analysis that can characterize computationally the motion that the end-effector of an industrial robot of general morphology (i.e. serial, parallel, hybrid manipulators, complex mechanisms, redundant or nonredundantly actuated). Also, being implemented on a general-purpose software for the kinematic analysis of mechanisms, it provides visual information of the motion capabilities of the manipulator, highly valuable on its design stages. © Emerald Group Publishing Limited.


Grant
Agency: Cordis | Branch: FP7 | Program: CP | Phase: ICT-2007.3.4 | Award Amount: 2.79M | Year: 2008

The objective of the GENESYS project is to develop a cross-domain reference architecture for embedded systems that can be instantiated for different application domains to meet the requirements and constraints documented in the ARTEMIS strategic research agenda. These requirements are composability, networking, security, robustness, diagnosis, integrated resource management and evolvability. The reference architecture will address common issues, such as complexity management, separation of communication and computation, support for different levels of quality of service, security, model-based design, heterogeneity of subsystems, legacy integration, optimal power usage, and diagnosis. It will provide domain-independent services that can be customized to the needs of a particular application domain. Domain-specific platform services will be converged such that components from different application domains can be consistently integrated while preserving relevant properties. The project will result in a conceptualization of the cross-domain architecture, a specification of cross-domain core services and optional services for the selected application domains, and four exploratory prototypes that will demonstrate and help to evaluate the feasibility of selected central architectural concepts in the different application domains. The expected impact of GENESYS is a reduction of development costs and a speed-up of the time-to-market of embedded system development in different application domains, thereby strengthening the European presence in the competitive world-wide embedded systems markets. The support for cross-domain reuse of components is of particular relevance to innovative European SMEs that plan to enter those markets with high-tech products under increasing time pressure. The consortium consists of many major European embedded system suppliers and OEMs encompassing a broad range of application domains, supported by leading research and academic organizations.


Gomez Gonzalez A.,University of Southern California | Rodriguez J.,University of Southern California | Sagartzazu X.,Ikerlan S. Coop. | Schuhmacher A.,Brüel and Kjær Vibro | Isasa I.,Elevator Innovation Center
Proceedings of ISMA 2010 - International Conference on Noise and Vibration Engineering, including USD 2010 | Year: 2010

In this work we analyze the transmission paths of noise and vibration through the multiple coherence method. The non-stationariness of the signals in our applications motivates the introduction of the time variable. The analysis is performed using Fast Fourier transform-based techniques and auto-regressive modeling. These methods will be compared in terms of computational expenses and reliability. We illustrate their behavior computing the power spectral density and the coherence of synthetic and experimental stationary and nonstationary signals.


Zugasti E.,Ikerlan S. Coop. | Gomez Gonzalez A.,University of Santiago de Compostela | Anduaga J.,Ikerlan S. Coop. | Arregui M.A.,Ikerlan S. Coop. | Martinez F.,Ikerlan S. Coop.
Smart Materials and Structures | Year: 2012

In this paper we present the application of two damage detection methods to a laboratory tower. The first method is based on subspace identification. The second one is based on AutoRegressive modeling of the signals involved. Both methods are tested in a tower demonstrator simulating a wind turbine. They are able to correctly detect damage in the structure that is simulated by loosening some of the bolts in the joints. The results show that the first method is computationally more efficient, but the results are more stable with the second method. © 2012 IOP Publishing Ltd.


Sarrado C.,University of Girona | Turon A.,University of Girona | Renart J.,University of Girona | Urresti I.,Ikerlan S. Coop.
Composites Part A: Applied Science and Manufacturing | Year: 2012

The use of cohesive elements to simulate delamination growth involves modeling the inelastic region existing ahead of the crack tip. Recent numerical and experimental findings indicate that the mixed-mode ratio varies at each material point within the inelastic region ahead of the crack tip during crack propagation, even for those specimens whose mixed-mode ratio is expected to be constant. Although the local variation of the mode mixity may adversely affect the predicted numerical results, most existing formulations do not take it into account. In this work, the mode-decomposed J-integral is implemented as a finite element post-processing tool to obtain the strain energy release rates and the mixed-mode ratio of the inelastic region as a whole, allowing the assessment of crack propagation in terms of energy dissipation and mixed-mode ratio computation. Different cohesive elements are assessed with this method. © 2012 Elsevier Ltd. All rights reserved.


PubMed | Ikerlan S. Coop.
Type: Journal Article | Journal: Biosensors & bioelectronics | Year: 2012

Here, we describe new fabrication methods aimed to integrate planar tetrode-like electrodes into a polymer SU-8 based microprobe for neuronal recording applications. New concepts on the fabrication sequences are introduced in order to eliminate the typical electrode-tissue gap associated to the passivation layer. Optimization of the photolithography technique and high step coverage of the sputtering process have been critical steps in this new fabrication process. Impedance characterization confirmed the viability of the electrodes for reliable neuronal recordings with values comparable to commercial probes. Furthermore, a homogeneous sensing behavior was obtained in all the electrodes of each probe. Finally, in vivo action potential and local field potential recordings were successfully obtained from the rat dorsal hippocampus. Peak-to-peak amplitude of action potentials ranged from noise level to up to 400-500 V. Moreover, action potentials of different amplitudes and shapes were recorded from all the four recording sites, suggesting improved capability of the tetrode to distinguish from different neuronal sources.

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