Conducting Polymer Microtubes for Bioactuators

Conducting polymer (CP) actuators are promising devices for biomedical applications such as artificial muscles and drug delivery systems. Here, we report a tri-layer actuator based on poly(pyrrole) (PPy) microtubes (PPy MTs) doped with poly(sodium-p-styrenesulfonate) (PSS) and constructed on a passive layer of gold-coated poly-propylene (PP) film. The PPy MTs were fabricated using electrochemical deposition of PPy around poly(lactic-co-glycolic acid) (PLGA) fiber templates, followed by template removal. The PPy MTs were subjected to a redox process using cyclic voltammetry in 0.1 M NaPSS electrolyte solution as the potential was swept between -0.8 V and +0.4 V for 5 cycles at the scan rates of 10, 50, 100, and 200 mV/s. The bending behavior of the PPy MTs actuator was investigated by measuring the deflection of actuator tip resulting from the expansion/contraction strain of PPy MTs. The PPy MTs actuator showed a reversible bending movement during each potential cycle. The maximum deflection of actuator decreased by increasing the scan rate that was confirmed by calculating the actuation strain generated during each cycle at various scan rates.