Polypyrrole based switchable filter system

BioTex is an EU funded project aiming to develop textile-based sensors for monitoring biological fluids. In the context of the project, there is a need to develop an effective sample delivery strategy for the wearable biomedical devices. A compact, electroactive switchable membrane would be useful as a valve to control the sample delivery within such devices. A method that employed inherently conducting polymers deposited onto a permeable substrate to form a switchable membrane was investigated [1, 2, 3]. By application of specific voltages, the permeability (pore size) of the membrane can be switched to swollen (expand) and contracted forms, which functions as electroactive plug or valve to manipulate the transport of liquid. It was anticipated that such switchable filter system would form the first stage in the development of a novel wearable platform in liquid handling, particularly for the transport of electro inactive species. It is expected that the use of a nano porous membrane promises advantages in improving the mechanical durability and performance in altering flow rate.