pps proceeding - Abstract Preview
pps proceeding
Symposium: S03 - Foams
Poster Presentation
 
 

Production of polymer wicks for bioelectric sensors

Martins Ana (1), Machado Ana Vera (1), Vaz Filipe (2), Fonseca Carlos (3), Nobrega Joao Miguel (1)*

(1) Institute for Polymers and Composites-I3N, University of Minho - Guimaraes - Portugal, (2) Centro de Física, Universidade do Minho - Braga - Portugal, (3) SEG-CEMUC-University of Coimbra and Universidade do Porto - Porto - Portugal

The monitoring of bioelectric signals by electroencephalography (EEG) is a common procedure, which provides medical data required for clinical applications and research. Currently, the application of EEG lacks alternatives to commonly used electrodes, which have several limitations and problems. The work reported here is included in a broader project that aims to develop a new concept of electrode that will combine the advantage of both “wet” and “dry” electrodes, circumventing most of the disadvantages of those specific individual electrodes. The new electrode comprises a polymer wick which will promote a low impedance electrode-skin contact, by delivering a small amount of a moistener solution to that region, thus it will dispense the application of the usual gel paste used in conventional applications. Wicks are porous and hydrophilic structures that are commonly used to absorb and transport liquids. They are usually produced using the sintering process, where a cohesive material is formed through mass diffusion, which takes place between small particles of the powder polymer. In this work the sintering process was studied in order to identify the effect of the most relevant process parameters (pressure, temperature and time) on the morphology of the produced wicks. The study was performed for three different materials: polycarbonate (PC), ultra high molecular weight polyethylene (UHMWPE) and polyamide 12 (PA 12). The results obtained allowed to conclude that: (i) the PC allowed the achievement of the best mechanical properties, due to its high yield stress and Young modulus; (ii) in terms of the processing parameters the best performing wicks were obtained with medium pressure, high cycle time, small particle size and medium temperature.