ABSTRACT El objetivo del presente artículo es presentar el diseño completo de un bioMEMS (biologi... more ABSTRACT El objetivo del presente artículo es presentar el diseño completo de un bioMEMS (biological Micro-Electro-Mechanical-System) formado por un sensor magnetorresistivo y su correspondiente estructura microfluídica. Se ha trabajado con un sensor de película delgada sobre sustrato de silicio para el cual se ha definido una red de canales que permitirán conducir el fluido al área donde se encuentra la superficie sensible del mismo. Para fabricar la estructura de canales se ha optado por el polidimetilsiloxano (PDMS), un material que debido a sus propiedades permite un procesado relativamente sencillo y su unión al silicio sin adhesivos adicionales.
ABSTRACT A new method to enhance surface-sample interaction in biosensors through the integration... more ABSTRACT A new method to enhance surface-sample interaction in biosensors through the integration of specific 3D microfluidic structures is reported. The method was tested in a device with a microfluidic network made from PDMS. The fabrication process included a specific double layer mold fabrication. As an intermediate step before the tests, a self assembled monolayer (SAM), that acted as a ligand for 252 nm amine-coated fluorescent polystyrene particles, was formed on top of a gold layer. The results showed that the microstructures produced an increase of coverage of the sensitive areas up to 15% which, combined with the property of the SAM of binding with different biological molecules, provide a potential method to enhance the sensitivity of a wide range of multipurpose microfluidic biosensors.
The Journal of neuroscience : the official journal of the Society for Neuroscience, Jan 22, 2003
Theories of incentive motivation attempt to capture the way in which objects and events in the wo... more Theories of incentive motivation attempt to capture the way in which objects and events in the world can acquire high motivational value and drive behavior, even in the absence of a clear biological need. In addition, for an individual to select the most appropriate goal, the incentive values of competing desirable objects need to be defined and compared. The present study examined the neural substrates by which appetitive incentive value influences prospective goal selection, using positron emission tomographic neuroimaging in humans. Sated subjects were shown a series of restaurant menus that varied in incentive value, specifically tailored for each individual, and in half the trials, were asked to make a selection from the menu. The amygdala was activated by high-incentive menus regardless of whether a choice was required. Indeed, activity in this region varied as a function of individual subjective ratings of incentive value. In contrast, distinct regions of the orbitofrontal co...
ABSTRACT A new circular position sensor based on giant magnetoresistances has been developed. The... more ABSTRACT A new circular position sensor based on giant magnetoresistances has been developed. The sensing film is an Agx-Co1-x nanogranular thin film patterned in a circular Wheatstone bridge configuration over an alumina substrate. This alloy shows a high magnetoresistance of 8% at room temperature within the field generated by a neodymium-iron-boron permanent magnet. The sensor provides a sensitivity of 440 muV/V/(º) with an input voltage of 5V. The operation temperature range of this device is 40ºC~+120ºC although the magnetic film withstands higher temperatures up to 200ºC. The sensor assembly is able to attach an electronic interface in the rear of the alumina substrate to amplify and compensate the output signal. These parameters and the contact-less way of sensing make this device suitable for automotive applications. In addition, the sensor is insensitive to contamination, and devoid of friction and electrical contact noise therefore the sensor have a long lifetime.
ABSTRACT Different multipurpose platforms were designed, fabricated and characterized to enable k... more ABSTRACT Different multipurpose platforms were designed, fabricated and characterized to enable key analyses of cell behavior and function at single cell level namely cell-cell interactions or cell migration under controlled conditions. The developed designs offer several advantages over previous approaches including high throughput, simplicity in experimental setup and control, and potential for coupling it to different substrates. Key parameters for optimum fabrication, efficient cell capture and seeding with high viability were established. Further, important factors for long-term experiments were defined. Cleanness and versatility of this microfluidic device makes it a potential tool of high interest in cell-based drug testing, cancer research or cell therapy.
ABSTRACT Among different physical principles magnetic sensors for low magnetic field detection ca... more ABSTRACT Among different physical principles magnetic sensors for low magnetic field detection can be based on, granular giant magnetoresistances have been studied due to their high sensitivity to small field changes and gradual magnetoresistance change at low fields. Following this aim, nanogranular Ag–Co thin films, deposited by DC co-sputtering from Ag and Co targets at different deposition temperatures have been tested. Samples have been grown at room temperature, 100 and 200°C and annealed in a mixture of N2 and H2 at 200 and 300°C for 45min. The samples that have shown the best performance have been subjected to two sets of measurements where an external field has been applied in-plane and perpendicular to the film plane. The best performance has been shown by the samples deposited at room temperature and annealed at 300°C, reporting a maximum value of magnetoresistance of 16.7% at 1.4T and a linear sensitivity of 63%/T between 0.04 and 0.07T within a magnetoresistance range varying from 1.5% to 3% when subjected to an in-plane external field.
... S. Arana*, E. Castaiio, FJ Gracia Centro de Estudios e Investigaciones TBcnicas de Gipuzkoa (... more ... S. Arana*, E. Castaiio, FJ Gracia Centro de Estudios e Investigaciones TBcnicas de Gipuzkoa (CEIT), Paseo de Manuel Lardizabal 15, PO Box 1555,20018 San Sebastian, Spain. Phone: + 34 943 212 800. ... Mag. Mat.114, L230 (1992). [6] John Q. Xiao, J. Samuel Jiang, and CL ...
ABSTRACT El objetivo del presente artículo es presentar el diseño completo de un bioMEMS (biologi... more ABSTRACT El objetivo del presente artículo es presentar el diseño completo de un bioMEMS (biological Micro-Electro-Mechanical-System) formado por un sensor magnetorresistivo y su correspondiente estructura microfluídica. Se ha trabajado con un sensor de película delgada sobre sustrato de silicio para el cual se ha definido una red de canales que permitirán conducir el fluido al área donde se encuentra la superficie sensible del mismo. Para fabricar la estructura de canales se ha optado por el polidimetilsiloxano (PDMS), un material que debido a sus propiedades permite un procesado relativamente sencillo y su unión al silicio sin adhesivos adicionales.
ABSTRACT A new method to enhance surface-sample interaction in biosensors through the integration... more ABSTRACT A new method to enhance surface-sample interaction in biosensors through the integration of specific 3D microfluidic structures is reported. The method was tested in a device with a microfluidic network made from PDMS. The fabrication process included a specific double layer mold fabrication. As an intermediate step before the tests, a self assembled monolayer (SAM), that acted as a ligand for 252 nm amine-coated fluorescent polystyrene particles, was formed on top of a gold layer. The results showed that the microstructures produced an increase of coverage of the sensitive areas up to 15% which, combined with the property of the SAM of binding with different biological molecules, provide a potential method to enhance the sensitivity of a wide range of multipurpose microfluidic biosensors.
The Journal of neuroscience : the official journal of the Society for Neuroscience, Jan 22, 2003
Theories of incentive motivation attempt to capture the way in which objects and events in the wo... more Theories of incentive motivation attempt to capture the way in which objects and events in the world can acquire high motivational value and drive behavior, even in the absence of a clear biological need. In addition, for an individual to select the most appropriate goal, the incentive values of competing desirable objects need to be defined and compared. The present study examined the neural substrates by which appetitive incentive value influences prospective goal selection, using positron emission tomographic neuroimaging in humans. Sated subjects were shown a series of restaurant menus that varied in incentive value, specifically tailored for each individual, and in half the trials, were asked to make a selection from the menu. The amygdala was activated by high-incentive menus regardless of whether a choice was required. Indeed, activity in this region varied as a function of individual subjective ratings of incentive value. In contrast, distinct regions of the orbitofrontal co...
ABSTRACT A new circular position sensor based on giant magnetoresistances has been developed. The... more ABSTRACT A new circular position sensor based on giant magnetoresistances has been developed. The sensing film is an Agx-Co1-x nanogranular thin film patterned in a circular Wheatstone bridge configuration over an alumina substrate. This alloy shows a high magnetoresistance of 8% at room temperature within the field generated by a neodymium-iron-boron permanent magnet. The sensor provides a sensitivity of 440 muV/V/(º) with an input voltage of 5V. The operation temperature range of this device is 40ºC~+120ºC although the magnetic film withstands higher temperatures up to 200ºC. The sensor assembly is able to attach an electronic interface in the rear of the alumina substrate to amplify and compensate the output signal. These parameters and the contact-less way of sensing make this device suitable for automotive applications. In addition, the sensor is insensitive to contamination, and devoid of friction and electrical contact noise therefore the sensor have a long lifetime.
ABSTRACT Different multipurpose platforms were designed, fabricated and characterized to enable k... more ABSTRACT Different multipurpose platforms were designed, fabricated and characterized to enable key analyses of cell behavior and function at single cell level namely cell-cell interactions or cell migration under controlled conditions. The developed designs offer several advantages over previous approaches including high throughput, simplicity in experimental setup and control, and potential for coupling it to different substrates. Key parameters for optimum fabrication, efficient cell capture and seeding with high viability were established. Further, important factors for long-term experiments were defined. Cleanness and versatility of this microfluidic device makes it a potential tool of high interest in cell-based drug testing, cancer research or cell therapy.
ABSTRACT Among different physical principles magnetic sensors for low magnetic field detection ca... more ABSTRACT Among different physical principles magnetic sensors for low magnetic field detection can be based on, granular giant magnetoresistances have been studied due to their high sensitivity to small field changes and gradual magnetoresistance change at low fields. Following this aim, nanogranular Ag–Co thin films, deposited by DC co-sputtering from Ag and Co targets at different deposition temperatures have been tested. Samples have been grown at room temperature, 100 and 200°C and annealed in a mixture of N2 and H2 at 200 and 300°C for 45min. The samples that have shown the best performance have been subjected to two sets of measurements where an external field has been applied in-plane and perpendicular to the film plane. The best performance has been shown by the samples deposited at room temperature and annealed at 300°C, reporting a maximum value of magnetoresistance of 16.7% at 1.4T and a linear sensitivity of 63%/T between 0.04 and 0.07T within a magnetoresistance range varying from 1.5% to 3% when subjected to an in-plane external field.
... S. Arana*, E. Castaiio, FJ Gracia Centro de Estudios e Investigaciones TBcnicas de Gipuzkoa (... more ... S. Arana*, E. Castaiio, FJ Gracia Centro de Estudios e Investigaciones TBcnicas de Gipuzkoa (CEIT), Paseo de Manuel Lardizabal 15, PO Box 1555,20018 San Sebastian, Spain. Phone: + 34 943 212 800. ... Mag. Mat.114, L230 (1992). [6] John Q. Xiao, J. Samuel Jiang, and CL ...
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