Publications

Export 33 results:
Sort by: Author [ Title  (Asc)] Type Year
A B C [D] E F G H I J K L M N O P Q R S T U V W X Y Z   [Show ALL]
A
Neagu, E. R., J. N. MaratMendes, D. K. Dasgupta, R. M. Neagu, and R. Igreja. "Analysis of the thermally stimulated discharge current around glass-rubber transition temperature in polyethylene terephthalate." Journal of Applied Physics. 82 (1997): 2488-2496. Abstract
n/a
Neagu, E. R., J. N. MaratMendes, D. K. Dasgupta, R. M. Neagu, and R. Igreja. "Analysis of the thermally stimulated discharge current around glass-rubber transition temperature in polyethylene terephthalate." Journal of Applied Physics. 82 (1997): 2488-2496. Abstract
n/a
Igreja, R., and C. J. Dias. "Analytical evaluation of the interdigital electrodes capacitance for a multi-layered structure." Sensors and Actuators a-Physical. 112 (2004): 291-301. AbstractWebsite

n/a

C
Igreja, R., C. J. Dias, R. Martins, E. Fortunato, I. Ferreira, and C. Dias. "Capacitance response of polysiloxane films with interdigital electrodes to volatile organic compounds." Advanced Materials Forum Ii. Vol. 455-456. 2004. 420-424. Abstract
n/a
Neagu, E. R., C. J. Dias, M. C. Lanca, R. Igreja, P. Inacio, and J. N. Marat-Mendes. "Charge Carriers Injection/Extraction at the Metal-Polymer Interface and Its Influence in the Capacitive Microelectromechanical Systems-Switches Actuation Voltage." Journal of Nanoscience and Nanotechnology. 10 (2010): 2503-2511. Abstract
n/a
Vieira, Eliana M. F., Sergey Levichev, Carlos J. Dias, Rui Igreja, Maja Buljan, Sigrid Bernstorff, Olinda Conde, Adil Chahboun, Anabela G. Rolo, and Maria J. M. Gomes. "Charge storage behavior of nanostructures based on SiGe nanocrystals embedded in Al2O3 matrix." European Physical Journal B. 86 (2013). Abstract
n/a
D
Basilio, A., R. Igreja, P. Inacio, C. Dias, and J. Marat-Mendes. "Development of an ultrasonic motor based on a piezoelectric ceramic sandwiched between two laminate composite plates." Advanced Materials Forum Iii, Pts 1 and 2. Ed. P. M. Vilarinho. Vol. 514-516. Materials Science Forum, 514-516. 2006. 221-224. Abstract
n/a
Igreja, R., C. J. Dias, J. N. Marat-Mendes, and NM White. "Development of ferroelectric ceramic/polymer composites for electro-active sensors applications." Eurosensors Xii, Vols 1 and 2. 1998. 473-476. Abstract
n/a
Igreja, R., and C. J. Dias. "Dielectric response of interdigital chemocapacitors: The role of the sensitive layer thickness." Sensors and Actuators B-Chemical. 115 (2006): 69-78. Abstract
n/a
Neagu, E. R., C. J. Dias, M. C. Lanca, R. Igreja, P. Inacio, J. N. Marat-Mendes, and Ieee Discrimination between Space Charge and Dipolar Contributions in Ferroelectric Polymers., 2011. Abstract

The final thermally stimulated discharge current method allows a better selection of the experimental conditions for sample polarization. By decreasing the ratio between the charging time and the discharging time, the apparent peak is of the same order of magnitude as the genuine peaks and there is only a partial overlap between then. Two peaks have been identified for polyamide 11, one associated with the glass transition around 60 degrees C and the second associated with the Curie transition around 96 degrees C.

E
Neagu, B., E. R. Neagu, R. Igreja, C. Dias, AMP Pinto, and AS Pouzada. "Electric Field Distribution Around the Deep Brain Stimulation Electrode Inferred from Dielectric Measurements." Advanced Materials Forum Vi, Pts 1 and 2. 730-732 (2013): 26-31. Abstract
n/a
Igreja, R., H. Domingos, J. P. Borges, C. J. Dias, AMP Pinto, and AS Pouzada. "Enhancing the Response of Chemocapacitors with Electrospun Nanofiber Films." Advanced Materials Forum Vi, Pts 1 and 2. 730-732 (2013): 197-202. Abstract
n/a
Igreja, Rui, and C. J. Dias. "Extension to the analytical model of the interdigital electrodes capacitance for a multi-layered structure." Sensors and Actuators a-Physical. 172 (2011): 392-399. Abstract

Interdigital electrodes (IE) are one of the most used transducers in different technical and analytical applications with the particular importance in the field of chemical and biological sensors. With the recent demand for lab-on-a-chip devices and the need for sensors miniaturization it becomes common the use of such transducers in structures with several dielectric layers (either substrates or superstrates). In a previous a work we proposed a model for the computation of the capacitance of these multi-layered structures using the techniques of conformal mapping and partial capacitance. Until now, that model has been used in applications where the permittivity of consecutive layers monotonically decreases from layer to layer (as we move away from the electrodes plane) giving excellent results. New applications, such as the use of Si/SiO2 substrates (to promote very smooth surfaces for electrodes deposition) or the use of passivation layers for the protection of electrodes (e.g. from liquids), among others, represent a new challenge for the computation of the overall capacitance since in these devices the permittivity can decrease from layer to layer. Under these conditions the original partial capacitance technique needs to be modified to include these new configurations. In this work we will discuss a new approach, splitting the concept of partial capacitance in parallel partial capacitance and serial partial capacitance where new conformal mapping transformations are proposed for the latter case. Hence this novel approach will extend our previous analytical model in order to account for the cases where there is a decrease in the permittivity from layer to layer. The results are compared with finite element simulation and experimental results. (C) 2011 Elsevier B.V. All rights reserved.

I
Sanguino, Pedro, Tiago Monteiro, Frederico Marques, Carlos J. Dias, Rui Igreja, and Ricardo Franco. "Interdigitated Capacitive Immunosensors With PVDF Immobilization Layers." Ieee Sensors Journal. 14 (2014): 1260-1265. Abstract
n/a
M
Neagu, E. R., C. J. Dias, M. C. Lanca, R. Igreja, and J. N. Marat-Mendes. "Medium Electric Field Electron Injection/Extraction at Metal-Dielectric Interface." Advanced Materials Forum V, Pt 1 and 2. Eds. L. G. Rosa, and F. Margarido. Vol. 636-637. Materials Science Forum, 636-637. 2010. 437-443. Abstract
n/a
O
Neagu, E. R., C. J. Dias, M. C. Lanca, R. Igreja, P. Inacio, J. N. Marat-Mendes, and Ieee. "On the Width of the Thermally Stimulated Discharge Current Peak." Proceedings of the 2010 Ieee International Conference on Solid Dielectrics. IEEE International Conference on Solid Dielectrics-ICSD. 2010. Abstract
n/a
Igreja, R., and C. J. Dias. "Organic vapour discrimination using sorption sensitive chemocapacitor arrays." Advanced Materials Forum Iii, Pts 1 and 2. Ed. P. M. Vilarinho. Vol. 514-516. Materials Science Forum, 514-516. 2006. 1064-1067. Abstract
n/a
P
Igreja, R., C. Dias, and J. Marat-Mendes. "Processing and characterization of sol-gel derived modified PbTiO(3) for ferroelectric composites." Ferroelectrics. 228 (1999): 99-109. Abstract
n/a
Igreja, R., C. Dias, and J. Marat-Mendes. "Processing and characterization of sol-gel derived modified PbTiO(3) for ferroelectric composites." Ferroelectrics. 228 (1999): 99-109. Abstract
n/a
Igreja, R., C. J. Dias, and J. N. MaratMendes. "Processing and characterization of sol-gel derived modified PbTiO3 for ferroelectric composite applications." Journal of Sol-Gel Science and Technology. 8 (1997): 721-723. Abstract
n/a
Igreja, R., M. P. Wenger, C. J. Dias, D. K. Dasgupta, and J. N. MaratMendes PYROELECTRICITY AND PIEZOELECTRICITY IN SOL-GEL DERIVED CERAMIC POLYMER COMPOSITES., 1994. Abstract
n/a
Igreja, R., M. P. Wenger, C. J. Dias, D. K. Dasgupta, J. N. MaratMendes, J. Lewiner, D. Morisseau, and C. Alquie. "PYROELECTRICITY AND PIEZOELECTRICITY IN SOL-GEL DERIVED CERAMIC POLYMER COMPOSITES." Ise 8 - 8th International Symposium on Electrets, Proceedings (1994): 725-730. Abstract
n/a
R
Dias, C. J., R. Igreja, R. Marat-Mendes, P. Inacio, J. N. Marat-Mendes, and D. K. Das-Gupta. "Recent advances in ceramic-polymer composite electrets." Ieee Transactions on Dielectrics and Electrical Insulation. 11 (2004): 35-40. Abstract
n/a
S
Kitsara, M., D. Goustouridis, S. Chatzandroulis, M. Chatzichristidi, I. Raptis, T. Ganetsos, R. Igreja, and C. J. Dias. "Single chip interdigitated electrode capacitive chemical sensor arrays." Sensors and Actuators B-Chemical. 127 (2007): 186-192. Abstract
n/a