9 documents found, page 1 of 1
Hybrid multisite silicon neural probe with integrated flexible connector for in...
Novais, Ashley; Calaza, Carlos; Fernandes, José; Fonseca, Helder; Monteiro, Patricia; Gaspar, João; Jacinto, Luís Ricardo MonteiroMultisite neural probes are a fundamental tool to study brain function. Hybrid silicon/polymer neural probes combine rigid silicon and flexible polymer parts into one single device and allow, for example, the precise integration of complex probe geometries, such as multishank designs, with flexible biocompatible cabling. Despite these advantages and benefiting from highly reproducible fabrication methods on bot...
High‐performance and industrially viable nanostructured siOx layers for interfa...
Cunha, José M. V.; Oliveira, Kevin; Lontchi, Jackson; Lopes, Tomás S.; Curado, Marco A.; Barbosa, João R. S.; Vinhais, Carlos; Chen, Wei-ChaoHerein, it is demonstrated, by using industrial techniques, that a passivation layer with nanocontacts based on silicon oxide (SiOx) leads to significant improvements in the optoelectronical performance of ultrathin Cu(In,Ga)Se2 (CIGS) solar cells. Two approaches are applied for contact patterning of the passivation layer: point contacts and line contacts. For two CIGS growth conditions, 550 and 500 °C, the SiO...
“Introduction. Transnational Connections between Activists and the Global Cold ...
Fonseca, Helder; Saunders, Chris; Dallywater, LenaThis volume explores ways in which the liberation movements in Southern Africa were connected to people in the countries that were regarded as part of the `East’ in the Cold War decades of the 1960s, 1970s, and 1980s. The many different forms such connections took have been little investigated. The chapters that follow showcase studies of such interactions, at both leadership and grass-roots levels, seeking to ...
Highly-ordered silicon nanowire arrays for photoelectrochemical hydrogen evolut...
Thalluri, Sitaramanjaneya Mouli; Borme, Jerome; Xiong, Dehua; Xu, Junyuan; Li, Wei; Amorim, Isilda; Alpuim, P.; Gaspar, Joao; Fonseca, HelderVertically-aligned, highly-ordered silicon nanowire (SiNW) array photocathodes are fabricated employing e-beam lithography followed by deep reactive ion etching (DRIE) of Si. The effect of structural parameters of SiNWs, including wire diameter, length and inter-wire spacing, on their photoelectrocatalytic hydrogen evolution performance has been systematically investigated. Within the range of dimensions under ...
Novel magnetic readout for hybrid spintronic MEMS devices
Dias, Rosana A.; Moreira, Eurico Esteves; Ribeiro, Igor; Costa, Margaret; Fonseca, Helder; Cardoso, Susana; Freitas, PauloThis digest reports for the first time on the concept, fabrication and characterization of a spintronics magnetic readout for hybrid MEMS. The method uses magnetic sensors (spin valves) and permanent magnets (on both the movable and the fixed parts of the MEMS structure) to detect displacement. The use of such transduction method has several potential advantages: it allows a small form factor, straightforward r...
Amorphous oxygen-rich molybdenum oxysulfide Decorated p-type silicon microwire ...
Xiao-Qing Bao; Petrovykh, D. Y.; Alpuim, P.; Stroppa, Daniel G.; Guldris, Noelia; Fonseca, Helder; Costa, Margaret; Gaspar, Joao; Chuanhong JinWe report the fabrication of p-type silicon (Si) photocathodes consisting of well-ordered Si microwire (Si-MW) arrays coupled with non-precious and earth-abundant amorphous oxygen-rich molybdenum oxysulfide (MoOxSy) as both a hydrogen evolution catalyst and a passivation layer. The MoOxSyis conformally grown on the Si-MW surface through photo-assisted cyclic voltammetric (CV) deposition. By adjusting the cycle ...
Real-time operation and characterization of a high-performance time-based accel...
Dias, Rosana Maria Alves; Alves, Filipe Manuel Serra; Costa, Margaret; Fonseca, Helder; Cabral, Jorge; Gaspar, João; Rocha, Luís Alexandre MachadoAn accelerometer based on the electrostatic pull-in time of a microstructure is presented in this paper. The device uses a parallel-plate overdamped microstructure, and real-time control operation is performed using a field programmable gate array and high precision digital-to-analog converters. Both open-loop and closed-loop measurements are presented. The low noise is a key feature of this approach, which is ...
Fabrication and characterization of polymeric three-axis thermal accelerometers
Silva, Cátia Samanta Ribeiro; Noh, Jong; Fonseca, Helder; Pontes, A. J.; Gaspar, João; Rocha, Luís Alexandre MachadoThe concept, fabrication process, and characterization of a three-axis thermal accelerometer are presented in this paper. A combination of microelectromechanical systems (MEMS) technology with microinjection molding enables the realization of functional, highly complex 3D geometries at the microscale, used here for the fabrication of a fully integrated three-axis accelerometer. While conventional thermal accele...
Portugal e as Sociedades Europeias: Família, Revoluções Sexuais, Homogamia e Fr...
Fonseca, Helder; Guimarães, Paulo EduardoEste artigo analisa o comportamento conubial em Portugal no quadro do debate sobre o declínio das diferenças sociais na Europa desde 1880, visto pela óptica da universalização da "Família Europeia" e do casamento. A exploração extensiva da Amostra Histórica Portuguesa sobre a Mobilidade Social permitiu testar a hipótese na mudança dos padrões de comportamento conubial e de modernização das relações familiares e...