Synthesis and Characterization of Novel Ionoconductor Gels for Biomedical Applications in Space

Under the framework of the project Anomalous Long Term Effects in Astronauts, an experiment to study the risk for functional brain anomalies due to cosmic radiation during long manned missions, a new gel-type polymer electrolyte membrane for recording bioelectric signals in space has been developed. Ionic conducting gels have been formed by immobilizing liquid solutions, containing LiX salts (X = CIO4, CF3SO3) dissolved in 1,2-diethoxyethane (gly), using poly(methyl methacrylate) (PMMA) as the polymeric matrix. The electrical properties of these membranes have been studied using impedance spectroscopy, The membranes exhibit good mechanical and chemical stability and high conductivity at room temperature (10 3 to 10 4 S cm 1). The highest conductivity value has been determined for membranes prepared from LiCO4-gly-PMMA having molar composition 7.19/64.01/28.80%. Preliminary experiments on electroencephalogram signals recorded with this new gel showed that the recordings are almost identical to those measured simultaneously using a conventional apparatus. © 2001 The Electrochemical Society. [DOI: 10.1149/1.1415726] All rights reserved.