Fast Low-Voltage Electroactive Actuators. Using Nanostructured Polymer Electrolytes

Transcription

1 Supplementary Information Fast Low-Voltage Electroactive Actuators Using Nanostructured Polymer Electrolytes Onnuri Kim 1, Tae Joo Shin 2, and Moon Jeong Park 1,3* 1 Division of Advanced Materials Science (WCU), 2 Pohang Accelerator Laboratory (PAL), 3 Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Korea

2 Supplementary Figures Supplementary Figure S1. Cross-sectional morphology of the actuator. A monolithic trilaminar structure comprising PSS-b-PMB block copolymer and SWCNT electrodes. 2

3 Supplementary Figure S2. Effect of the amounts of ionic liquids on actuation performance. The displacement of the actuators comprising P17(75) and [HMIm][PF 6 ] at alternating square-wave voltages of ± 3 V and a frequency of Hz. The amounts of [HMIm][PF 6 ] loadings were varied from 45 to 60 wt%. 3

4 Supplementary Figure S3. Effects of types of ionic liquids on conductivity of polymer layers. Conductivities of the nanostructured P17(75) and the PVdF-HFP lacking organization with the incorporation of 60 wt% ionic liquids. The linear fits were obtained by Arrhenius plots and the types of ionic liquids are noted in the figure. Upon comparing the conductivity of PVdF-HFP copolymers incorporated with ionic liquids with that of the P17(75), the fact that higher conductivity was obtained for [HMIm][PF 6 ] than the value with [EMIm][PF 6 ] is consistent with the results of the P17(75). However, the conductivity of ionic liquidcontaining PVdF-HFP is less sensitive function of the types of ionic liquids, which bears resemblance to the strain values plotted in Figure 3b of the main manuscript. This implies that the existence of [ SO 3 H] groups in PSS-b-PMB copolymers made a great impact on the ion conduction and charging behavior of the actuators by manipulating ionic interaction within the polymer layers. 4

5 Supplementary Figure S4. Binding properties of ion pairs. Binding energies and coupling schemes of ion pairs, obtained by Ab initio calculation at 0K in a vacuum using a DFT Exchange-Correlation Functional. 5

6 Supplementary Figure S5. A direct comparison of actuation performance. Strainfrequency-voltage dependency of the actuator comprising P17(75) copolymer and [HMIm][PF 6 ] compared to the values reported in the literatures. The literature values were collected over 20 independent references, published during the past eight years, as listed in Supplementary References. 6

7 Supplementary Figure S6. Sub-1V actuation performance of our actuator and IPMCs actuators reported in literatures. Strain-voltage dependency of the actuator comprising P17(75) copolymer and 60 wt% [HMIm][PF 6 ], compared to the ionic polymer-metal composites (IPMCs) actuators reported in literatures with a focus on low voltage operation. The sub-1v actuator performance has been reported for a range of ionic polymer-metal composites (IPMCs) actuators, which include metal foil electrodes. Since the addition of metal foil layer to the ionic polymer actuator has known to result in a substantial improvement in the electromechanical deformation, by a few orders of magnitude [65], the direct comparison between our actuators and IPMCs actuators in literatures may not be proper. It is apparent that although our actuator does not hold the metal foil, its bending motion is comparable or superior to that of IPMCs actuators. 7

8 Supplementary References 53. Terasawa, N. Ono, N., Mukai, K., Koga, T., Higashi, N., Asakaet, K. A multi-walled carbon nanotube/polymer actuator that surpasses the performance of a single-walled carbon nanotube/polymer actuator. Carbon 50, (2012). 54. Terasawa, N., Takeuchi, I. Electrochemical and electromechanical properties of highperformance polymer actuators containing vapor grown carbon nanofiber and metal oxide. Sens. Actuators B 176, (2013). 55. Torop, J. Palmre, V., Arulepp, M., Sugino, T., Asaka, K., Aabloo, A. Flexible supercapacitor-like actuator with carbide- derived carbon electrodes. Carbon 49, (2011). 56. Sugino, T., Kiyohara, K., Takeuchi, I., Mukai, K., Asaka, K. Actuator properties of the complexes composed by carbon nanotube and ionic liquid: The effects of additives. Sens. Actuators B 141, (2009). 57. Palmre, V. Torop, J., Arulepp, M., Sugino, T., Asaka, K., Jänes, A., Lust, E., Aabloo, A. Impact of carbon nanotube additives on carbide-derived carbon-based electroactive polymer actuators. Carbon 50, (2012). 58. Biso, M., Ansaldo, A., Ricci, D. Geometry dependent performance of bucky gel actuators: Increasing operating frequency by miniaturization. Phys. Status Solidi B 249(12), (2012). 59. Lu, J., Kim, S. G., Lee, S., Oh, I-K. A Biomimetic Actuator Based on an Ionic Networking Membrane of Poly(styrene-alt-maleimide)-Incorporated Poly(vinylidene fluoride). Adv. Funct. Mater. 18, (2008). 60. Hatipoglu, G., Liu, Y., Zhao, R., Yoonessi, M., Tigelaar, D. M., Tadigadapa, S., Zhang, Q. M. A highly aromatic and sulfonated ionomer for high elastic modulus ionic polymer membrane micro-actuators. Smart Mater. Struct. 21, (2012). 61. Shahinpoor, M., Bar-Cohen, Y., Simpson, J. O., Smith, J. Ionic polymer-metal composites (IPMC's) as biomimetic sensors, actuators and artificial muscles - a review. Smart Mater. Struct. 7, R15-R30 (1998). 8

9 62. Alici, G., Huynha, N. N. Predicting force output of trilayer polymer actuators. Sens. Actuators A 132, (2006). 63. Torop, J., Sugino, T., Asaka, K., Jänes, A., Lust, E., Aabloo, A. Nanoporous carbidederived carbon based actuators modified with gold foil: Prospect for fast response and low voltage applications. Sens. Actuators B 161, (2012). 64. Nemat-Nasser, S., Li, J. Y. Electromechanical response of ionic polymer-metal composites. J. Appl. Phys. 87, (2000). 9