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International Journal of Polymer Science
Volume 2014 (2014), Article ID 713603, 12 pages
Research Article

Towards a Smart Encapsulation System for Small-Sized Electronic Devices: A New Approach

1Fraunhofer Institute for Biomedical Engineering IBMT, Branch Potsdam, Am Muehlenberg 13, 14476 Potsdam, Germany
2Institute for Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany

Received 11 October 2013; Revised 19 December 2013; Accepted 20 December 2013; Published 9 February 2014

Academic Editor: Qijin Zhang

Copyright © 2014 Sebastian-Tim Schmitz-Hertzberg et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Miniaturized analytical chip devices like biosensors nowadays provide assistance in highly diverse fields of application such as point-of-care diagnostics and industrial bioprocess engineering. However, upon contact with fluids, the sensor requires a protective shell for its electrical components that simultaneously offers controlled access for the target analytes to the measuring units. We therefore developed a capsule that comprises a permeable and a sealed compartment consisting of variable polymers such as biocompatible and biodegradable polylactic acid (PLA) for medical applications or more economical polyvinyl chloride (PVC) and polystyrene (PS) polymers for bioengineering applications. Production of the sealed capsule compartments was performed by heat pressing of polymer pellets placed in individually designable molds. Controlled permeability of the opposite compartments was achieved by inclusion of NaCl inside the polymer matrix during heat pressing, followed by its subsequent release in aqueous solution. Correlating diffusion rates through the so made permeable capsule compartments were quantified for preselected model analytes: glucose, peroxidase, and polystyrene beads of three different diameters (1.4 μm, 4.2 μm, and 20.0 μm). In summary, the presented capsule system turned out to provide sufficient shelter for small-sized electronic devices and gives insight into its potential permeability for defined substances of analytical interest.