PDMS, a safe shelter for flexible W-BAN antennas

This contribution describes a new technology for the realization of soft, flexible, and robust antennas intended to operate in a harsh environment. The method is based on the use of a silicon based elastomer, Polydimethylsiloxane (PDMS) for the substrate material, and copper mesh or any kind of perforated metal plates as flexible conductive materials. The initial liquid state of the PDMS allows a lot of freedom in the fabrication process, both from the electrical and mechanical point of view. The electric and mechanic properties of the substrate can be adjusted by loading the PDMS with low or high permittivity inclusions, controlling thus the permittivity and the rigidity. Copper meshes or perforated metal structures enable good adhesion between the substrate and conductor and improve the overall flexibility. Measured results show good repetitiveness of the substrate samples, both with or without inclusions. Several antenna prototypes have been built and tested through washing and bending in order to assess their robustness to environmental changes.