The performance of Nafion-based IPMC actuators containing polypyrrole/alumina composite fillers

Abstract

A polypyrrole (PPy)/alumina composite filler prepared via in-situ polymerization of pyrrole on alumina particles was incorporated into Nafion ® to improve the performance of ionic polymer-metal composite (IPMC) actuators. The IPMCs with the pristine PPy without alumina support did not show bending displacements superior to that of the bare Nafion-based IPMC, except at a high PPy content of 4 wt%. This result was attributed to the low redox efficiency of the PPy alone in the IPMC and may have also been related to the modulus of the IPMC. However, at the optimized filler contents, the cyclic displacement of the IPMCs bearing the PPy/alumina filler was 2.2 times larger than that of the bare Nafion-based IPMC under an applied AC potential of 3 V at 1 Hz. Even under a low AC potential of 1.5 V at 1 Hz, the displacement of the PPy/alumina-based IPMCs was a viable level of performance for actuator applications and was 2.7 times higher than that of the conventional Nafion-based IPMC. The generated blocking force was also improved with the PPy/alumina composite filler. The greatly enhanced performance and the low-voltage-operational characteristic of the IPMCs bearing the PPy/alumina filler were attributed to the synergic effects of the neighboring alumina moiety near the PPy moiety involving electrochemical redox reactions.

Reliability tests of ionic polymer metallic composites in dry air for actuator applications

“…[14] Comparing the IPMC in a non-aqueous solution to a hydrated IPMC, a much higher driving voltage can be used to control the non-aqueous electrolyte IPMC with minimal electrolysis. This result also proves that a higher dielectric permittivity generates a higher electrolysis voltage [15].…”

Electrochemical and electromechanical behavior of Nafion-based soft actuators with PPy/CB/MWCNT nanocomposite electrodes

“…They showed that the energy efficiency of strain was over 10 times higher than that of the conventional IPMC actuators. 63 Various efforts have also been made to incorporate PPy into the Naon membrane 64,65 in order to improve the performance of IPMC actuators. Although there are reports on the actuation performance of CP-based actuators 34 the PPy-electrode Naon-based actuators have not been reported previously.…”

Force optimization of ionic polymer metal composite actuators by an orthogonal array method

“…It follows that high water content helps improve the steady operation capability of an IPMC. Lee et al [9] fabricated an IPMC containing a polypyrrole (PPy)/alumina composite filler to improve the water content and cation migration, which are attributed to the redox reaction of PPy and the hygroscopic effect of alumina. Compared with the bare Nafion IPMC, the maximum blocking force was doubled.…”

“…Lee et al [9] employed PPy/alumina composite filler as an additive for fabricating a high performance IPMC actuator (20×5×0.453 mm). The artificial muscle exhibited maximum force per unit thickness of 18 mN/mm under a DC voltage of 3 V. Nguyen et al [27] used Nafion membranes modified with two kinds of silicate materials (fumed silica and montmorillonite) as the polyelectrolytes of IPMCs (20 mm×5 mm×0.3 mm) to improve the performance.…”