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The Joyce, Lady Waters School of Chemical Sciences

Conducting Polymer Actuators and Micropumps

Contact Researchers: Assoc. Prof. Jadranka Travas-Sejdic, Assoc. Prof. Paul Kilmartin

Conducting polymers such as polypyrrole undergoing oxidation and reduction can be used to create actuating elements, ranging from bending strips several cm long to out-of-plane actuation on the micrometer scale. Research at PERC has focused upon optimising the performance of high strain (> 10%) linear actuators, and incorporating actuators into designs for micropumps which have been modelled in detail, along with further applications such as a robotic fish.

Linear actuation behaviour of PPy and PEDOT films

Free standing films of polypyrrole (PPy) and poly-3,4-ethylenedioxythiophene (PEDOT) have been prepared from propylene carbonate solutions and subject to electrochemomechanical deformation measurements during cyclic voltammetry and potential step experiments. A mixed-ion response was obtained under certain experimental conditions (Dr. Rudolf Kiefer). The effects of electrochemical synthesis conditions on the actuation performance and electrochemistry of free-standing films of polypyrrole have been investigated in the presence of trifluoromethanesulfonate in propylene carbonate or methyl benzoate (Shu Yi Chu - MSc). The long term stability of PPy based actuators during lengthy cycling is also being investigated and monitored using spectroscopic techniques (Dr Suad Jassim).

Alex and KC Li with the Aurora Dynamic Muscle Analyser

Incorporation of platinum nanoparticles

Various approaches for the incorporation of gold and platinum nanoparticles into composite conducting polymers are being examined to increase actuator conductivity and performance (Alexsandro Santos Costa - PhD).

Out-of-plane conducting polymer micropump

Polypyrrole based acutating elements are being used within microfluidic channels to create a micropump device. The conducting polymer elements have been characterised for their out-of-plane acutation using in situ electrochemical AFM (Dr Bryon Wright).

Microfluidics and mathematical modelling

Computational fluid mechanics and dimensional analysis have been applied as tools in the design of a microfluidic pump. The actuation of conducting polymer has been modelled in a range of potential pump designs, to determine flow rates and what most significantly affects flow rate, along with means to optimise design parameters. (Xerxes Mandviwalla - MSc with Dr Rosalind Archer). The out-of-plane actuation of conducting polymers and the generation of peristaltic movement within micro-channels is being examined, including the influence of system geometry and polymer composition in computational models (Karthik Kannappan - PhD in conjunction with Dr Gib Bogle from Bioengineering). The modelling group at Industrial Research Limited in Lower Hutt, involving Dr John Burnell, Dr Mike Arnold and Dr Graham Weir, has examined the peristaltic pumping action for out-of-plane conducting polymer actuation using computational fluid dynamics to evaluate fluid flow and the role of parameters such as channel height, actuator frequency and electrode configuration.

Robotic fish

Trilayer actuators constructed using 10 mm thick polypyrrole layers on a gold coated PDVF membrane were linked to a micro-controller, Li coin cell battery and circuitry, which were all encased in plastic to create a robotic fish driven remotely by an actuated tail. The prototype fish was able to run for 10-12 hours, limited by the battery life-time rather than the conducting polymer actuator (Sungkono Surya Tjahyono and Han Wang - Engineering students with Dr Bruce MacDonald).

Recent publications

  • P.A. Kilmartin and J. Travas-Sejdic, "Nanostructural aspects of conducting polymer actuators", In A. Eftekhari (ed.) Nanostructured Conductive Polymers. Wiley-VCH, (2010) in press.
  • A. Santos Costa, K.-C. Li, P.A. Kilmartin and J. Travas-Sejdic, "Incorporation of metallic nanoparticles into conducting polymer actuator films", AIP Conference Proceedings 1151 (Advanced Materials and Nanotechnology) (2009) 123-125.
  • R. Kiefer, G.A. Bowmaker, R.P. Cooney, P.A. Kilmartin and J. Travas-Sejdic, "Effect of Polymerisation Potential on the Actuation of Free Standing Poly-3,4-ethylenedioxythiophene Films in a Propylene Carbonate Electrolyte", Electrochimica Acta 55 (2010) 681-688.
  • S.Y. Chu, P.A. Kilmartin and J. Travas-Sejdic, "Effects of applied stress and long-term stability on PPy(CF3SO3) linear actuators", Synthetic Metals 159 (2009) 2286-2288.
  • J. Sui, J. Travas-Sejdic, S.Y. Chu, K.C. Li and P.A. Kilmartin, "The actuation behaviour and stability of p-toluene sulfonate doped polypyrrole films formed at different deposition current densities", Journal of Applied Polymer Science 111 (2009) 876-882.
  • X. Mandviwalla and R. Archer, "The influence of slip boundary conditiosn on peristaltic pumping in a rectangular channel", Journal of Fluids Engineering - Transactions of the ASME 130 (2008) 124501.
  • R. Kiefer, P.A. Kilmartin, G.A. Bowmaker, and J. Travas-Sejdic, "Electrochemomechanical behaviour of free standing PEDOT films in organic and aqueous electrolytes", Proceedings of SPIE-The International Society for Optical Engineering (2008) 6927 (EAPAD) San Diego) 692720.
  • R. Kiefer, X. Mandviwalla, R. Archer, S.S. Tjahyono, H. Wang, B. MacDonald, G.A. Bowmaker, P.A. Kilmartin and J. Travas-Sejdic, "The application of polypyrrole trilayer actuators in microfluidics and robotics", Proceedings of SPIE-The International Society for Optical Engineering (2008) 6927 (EAPAD) San Diego) 69271E.
  • S.Y. Chu, P.A. Kilmartin, J. Sui, G.A. Bowmaker, R.P. Cooney and J. Travas-Sejdic, "The effect of monomer and electrolyte concentrations during synthesis on the actuation of PPy(CF3SO3) films in aqueous electrolytes", Synthetic Metals 158 (2008) 38-44.
  • R. Kiefer, G.A. Bowmaker, R.P. Cooney, P.A. Kilmartin and J. Travas-Sejdic, "Cation driven actuation for free standing PEDOT films prepared from propylene carbonate electrolytes containing TBACF3SO3", Electrochimica Acta 53 (2008) 2593-2599.
  • S.Y. Chu, H. Peng, P.A. Kilmartin, G.A. Bowmaker, R.P. Cooney and J. Travas-Sejdic, "Effect of deposition current density on the linear actuation behaviour of PPy(CF3SO3) films", Current Applied Physics 8 (2008) 324-327.
  • R. Kiefer, P.A. Kilmartin, G.A. Bowmaker, R.P. Cooney and J. Travas-Sejdic, "Mixed-ion linear actuation of PPy and PEDOT in propylene carbonate-triflate electrolytes", Proceedings of SPIE-The International Society for Optical Engineering (2007) 6524 (Electroactive Polymer Actuators and Devices (EAPAD) San Diego) 6524OU.
  • M.B. Cannell, P. Kilmartin, M. Jacobs, S. Valiavalappil, J. Travas-Sejdic and C. Soeller, "Chapter 14: Nanoscale fluid motion via molecular pores and polymer actuators", Nano Biophotonics: Science and Technology, Ed. H. Masuhara, S. Kawata and F. Tokunaga, Elsevier, 2007, p.207-226.
  • R. Kiefer, P.A. Kilmartin, G.A. Bowmaker, R.P. Cooney and J. Travas-Sejdic, "Actuation of polypyrrole films in propylene carbonate electrolytes", Sensors and Actuators B 125 (2007) 628-634.
  • R. Kiefer, S.Y. Chu, P.A. Kilmartin, G. Bowmaker, R. Cooney and J. Travas-Sejdic, "Mixed-ion linear actuation behaviour of polypyrrole", Electrochimica Acta 52 (2007) 2386-2391.