心導管手術是一種診斷與治療心血管疾病之微創手術，傳統上手術進行時需藉由抽換不同曲率導引線才能將心導管跨越血管分岐處並伸入至心臟，此過程繁複耗時而造成臨床應用不便。新興的電驅動聚合物中，離子性聚合物與金屬複合材料（ionic polymer-metal composite, IPMC），簡稱離子複材，具有低電壓驅動下能產生大幅彎曲之特性，因此本研究主旨是藉由離子複材發展前端曲率可控制之心導管導引線，期望能減少導引線替換次數並縮短手術時間。為了因應離子複材複雜的物理化學特性以及導引線微小化和曲率控制等要求，本研究進程上分成四個子目標：（1）金質離子複材製程、（2）離子複材動態模型與機電特性分析、（3）適應性曲率回授控制以及（4）致動暨感測離子複材之發展。

　　傳統離子複材是在陽離子交換膜上下表面鍍上鉑金屬作為導電層所構成，致動前需令交換膜充滿電導液。為了降低製作成本和提昇可靠度，本研究除了提出以鎳基催化反應（nickel substrate-catalyzed reaction）製作金質導電層之離子複材，另一方面則是參考並改善文獻方法以充盈還原鍍金反應（impregnation-reduction reaction）製作離子複材。為了分析離子複材致動特性機電特性與後續之機械設計，本研究除了以系統識別理論建立動態系統經驗模型，亦推導參數具物理涵義之離子複材機電系統模型。為了控制各種致動環境下離子複材非線性且時變之曲率響應特性，本研究發展了自調式內嵌積分作用調節器（direct self-tuning regulator embedded with integrator, DSTR），其以具有積分作用之極零點控制器架構與性能參考模型以及參數估測機制所組成。由於常規感測器尺寸過大，離子複材響應回授控制通常難以實現於工作空間狹窄之應用，故本研究針對心導管手術另外提出了可切換感測或致動能力之離子複材設計，其利用調幅解調（amplitude modulation-demodulation）方式讀取離子複材因致動形變所造成的導電層電阻變化並以此作為形變感測訊號。

　　經實驗證實，本研究提出的鎳基催化鍍金製程僅需以常見的陰離子型金錯鹽便能在24小時內製作出金質離子複材，而充盈還原鍍金反應製程則需合成特殊的陽離子型金錯鹽且製程時間長逹48小時以上。由經驗模型可知離子複材為三至四階非極小相位系統，而本研究推導之機電系統模型指出，離子複材曲率響應變異主要與機械剛性、交換膜導電度和介電常數有關。在響應控制方面，本研究設計的DSTR控制器能於2 sec內估測出控制器參數，因此對於頻率低於1 Hz以下而振幅3 m^-1以內之任意波形命令其能有效控制響應使追踨誤差低於0.1 m^-1。本研究提出的調幅解調訊號處理流程可在無外加感測器的情況下透過離子複材表面導電層電阻變化估測出離子複材靜態或動態形變，並且藉由離子複材致動和感測功能之間的切換逹到減少心導管導引線抽換頻率以及定位效果。經主動導引模擬實驗得知本研究設計的離子複材導引線原型可穿越約150度之Y型分岐流道，未來若能進一步提昇離子複材致動力並微型化則可望將主動導引線實際應用於心導管手術。

Cardiac catheterization is one of minimally invasive surgeries to diagnose or to treat coronary heart diseases. The typical catheterization is inconvenient for the surgeons, owing to frequent changes of guidewires with different shapes and curvatures for steering a cardiac catheter to pass crotched vessels and into the heart. In the field of electroactive polymers, the ionic polymer-metal composite (IPMC) has the capability to generate large bending deformation by a low electrical driving power. The main goal of this study is to develop an active guidewire having tip-curvature that can be modulated by the IPMC, and this design may not only reduce the frequency of changing guidewires but also save the operation time. To explore the complicated physicochemical properties of the IPMC, miniaturize the guidewire and control the tip-curvature, the sub-goals of this study are: (1) the manufacture of the gold-based IPMC, (2) the dynamic model and the analyses of electromechanical properties for the IPMC, (3) adaptive curvature feedback control, and (4) the development of the sensing/actuating IPMC.

The IPMC typically consisted of a cation-exchange membrane sandwiched in two platinum layers as electrodes, and the membrane required to soak up conductive solvent before the actuation. For low cost and reliable fabrication of the IPMC, the nickel substrate-catalyzed reaction of gold electroless plating was proposed in this study. Besides, the impregnation-reduction reaction method suggested in the literatures was realized and improved to manufacture the gold-based IPMC. For analyzing the actuating characteristics and the mechanical design of the IPMC, not only an dynamic empirical model was constructed but also an electromechanical model with parameters having physical sense was derived. For controlling the nonlinear time-varying tip-curvature responses of the IPMCs actuated in varied environments, a direct self-tuning regulator with integral action (DSTR) was designed. It consisted of a pole-placement control structure embedded integral action, a reference model, and a self-tuning mechanism. Due to the bulky size of displacement sensors, the implementations of feedback controls of the IPMCs were infeasible for the cardiac catheterization. Thus a sensing/actuating IPMC transducer by employing the amplitude modulation-demodulation technique to obtain deformation of the sensing IPMC from the variation of electrical resistances was investigated.

In contrast to the impregnation-reduction reaction which employed a specific gold complex salt to produce a gold-based IPMC and consumed more than 48 hr production time, the nickel substrate-catalyzed reaction can utilize general gold complex to produce the IPMC within 24 hr. The IPMC was a 3rd or 4th order non-minimum phase dynamic system from the system identification result. Analyses by using the electromechanical model indicated that the variations of the tip-curvature responses depended on the mechanical stiffness of the IPMC, the conductivity and the dielectric constant of the ion-exchange membrane. The DSTR could achieve convergence of process parameters within 2 sec, and the controlled curvature could follow arbitrary waveform commands with frequency within 1 Hz and amplitude of 3 m^-1. The absolute tracking error was lower than 0.1 m^-1. For the sensing/actuating IPMC, the deformation-sensing approach based on the variation of surface resistances in the IPMC electrodes can estimate the static or dynamic deformation successfully without other sensors. Besides, a simulated catheterization demonstrated the potentials of reducing the frequent changes of guidewires and locating the tip-position in catheterization. The prototype of the IPMC guidewire could pass through a Y-shape bifurcation vessel of 150 degree smoothly. If the actuating force and the size of the IPMC can be enhanced and scaled down, the active guidewire will be realized to the cardiac catheterization.

[1] A.R.J. Mitchell, N.E.J. West, P. Leeson, and A.P. Banning, Cardiac catheterization and coronary intervention, OXFORD, 2007.
[2] Y. Bar-Cohen, Electroactive polymer (EAP) actuators as artificial muscles: reality, potential, and challenges, 2nd ed., SPIE Press, 2004.
[3] Y. Fu, H. Liu, W. Huang, S. Wang, and Z. Liang, "Steerable catheters in minimally invasive vascular surgery", Tthe International Journal of Medical Robotics and Computer Assisted Surgery, 2009.
[4] P. Kanagaratnam, M. Koa-Wing, D.T. Wallace, A.S. Goldenberg, N.S. Peters, and D.W. Davies, "Experience of robotic catheter ablation in humans using a novel remotely steerable catheter sheath", Journal of Interventional Cardiac Electrophysiology, 21 (1), 19-26, 2008.
[5] M.N. Faddis, W. Blume, J. Finney, A. Hall, J. Rauch, J. Sell, K.T. Bae, M. Talcott, and B. Lindsay, "Novel, magnetically guided catheter for endocardial mapping and radiofrequency catheter ablation", Circulation, 106 (23), 2980-2985, 2002.
[6] K. Ishiyama, M. Sendoh, and K.I. Arai, "Magnetic micromachines for medical applications", Journal of Magnetism and Magnetic Materials, 242, 41-46, 2002.
[7] S.R. Atmakuri, E.I. Lev, C. Alviar, E. Ibarra, A.E. Raizner, S.L. Solomon, and N.S. Kleiman, "Initial experience with a magnetic navigation system for percutaneous coronary intervention in complex coronary artery lesions", Journal of the American College of Cardiology, 47 (3), 515-521, 2006.
[8] B.D. Lindsay, "Perspectives on the development of a magnetic navigation system for remote control of electrophysiology catheters", Europace, 8 (4), 231-232, 2006.
[9] S. Ramcharitar, M.S. Patterson, R.J. van Geuns, M. van der Ent, G. Sianos, G.M.J.M. Welten, R.T. van Domburg, and P.W. Serruys, "A randomised controlled study comparing conventional and magnetic guidewires in a two-dimensional branching tortuous phantom simulating angulated coronary vessels", Catheterization and Cardiovascular Interventions, 70 (5), 662-668, 2007.
[10] S. Ramcharitar, M.S. Patterson, R.J. van Geuns, C. van Meighem, and P.W. Serruys, "Technology insight: magnetic navigation in coronary interventions", Nature Clinical Practice Cardiovascular Medicine, 5 (3), 148-156, 2008.
[11] M.A.E. Schneider, F.V. Hoch, H. Neuser, J. Brunn, M.L. Koller, F. Gietzen, R. Schamberger, S. Kerber, and B. Schumacher, "Magnetic-guided percutaneous coronary intervention enabled by two-dimensional guidewire steering and three-dimensional virtual angioscopy: Initial experiences in daily clinical practice", Journal of Interventional Cardiology, 21 (2), 158-166, 2008.
[12] Y. Haga, Y. Tanahashi, and M. Esashi. "Small diameter active catheter using shape memory alloy", in Micro Electro Mechanical Systems, 1998. MEMS 98. Proceedings., The Eleventh Annual International Workshop on, 1998.
[13] K.T. Park and M. Esashi, "A multilink active catheter with polyimide-based integrated CMOS interface circuits", Journal of Microelectromechanical Systems, 8 (4), 349-357, 1999.
[14] T. Mineta, T. Mitsui, Y. Watanabe, S. Kobayashi, Y. Haga, and M. Esashi, "Batch fabricated flat meandering shape memory alloy actuator for active catheter", Sensors and Actuators A-Physical, 88 (2), 112-120, 2001.
[15] T. Mineta, T. Mitsui, Y. Watanabe, S. Kobayashi, Y. Haga, and M. Esashi, "An active guide wire with shape memory alloy bending actuator fabricated by room temperature process", Sensors and Actuators A-Physical, 97-8, 632-637, 2002.
[16] A.T. Tung, B.H. Park, G. Niemeyer, and D.H. Liang. "Laser-Machined Shape Memory Alloy Actuators for Active Catheters", IEEE-ASME Trans, 12, 439-446, 2007.
[17] K. Ikuta, H. Ichikawa, K. Suzuki, and T. Yamamoto. "Safety active catheter with multi-segments driven by innovative hydro-pressure micro actuators", IEEE the 16th Annual International Conference, 130-135, 2003.
[18] Y. Haga, Y. Muyari, T. Mineta, T. Matsunaga, H. Akahori, and M. Esashi. "Small diameter hydraulic active bending catheter using Laser processed super elastic alloy and silicone rubber tube", The 3rd Annual Intemational IEEE EMBS Special Topic, Conf. on Microtechnologies in Medicine and Biology, 245-248, 2005.
[19] K. Ikuta, H. Ichikawa, K. Suzuki, and D. Yajima. "Multi-degree of Freedom Hydraulic Pressure Driven Safety Active Catheter", Proceedings of the 2006 IEEE International Conference on Robotics and Automation, 4161-4166, 2006.
[20] M. Ikeuchi and K. Ikuta. "Development of Pressure-Driven Micro Active Catheter using Membrane Micro Emboss Following Excimer Laser Ablation (MeME-X) Process", 2009 IEEE International Conference on Robotics and Automation, 4469-4472, 2009.
[21] S. Guo, T. Nakamura, T. Fukuda, K. Oguro, and M. Negoro. "Micro Active Guide Wire Using ICPF Actuator-characteristic evaluation, electrical model and operability evaluation", Proceedings of the 1996 IEEE IECON 22nd International Conference on, 2, 1312 - 1317, 1996.
[22] M. Shahinpoor and K.J. Kim, "Ionic polymer-metal composites: I. Fundamentals", Smart Materials & Structures, 10 (4), 819-833, 2001.
[23] M. Shahinpoor, Y. Bar-Cohen, J.O. Simpson, and J. Smith, "Ionic polymer-metal composites (IPMCs) as biomimetic sensors, actuators and artificial muscles - a review", Smart Materials & Structures, 7 (6), R15-R30, 1998.
[24] M. Shahinpoor and K.J. Kim, "Ionic polymer-metal composites: IV. Industrial and medical applications", Smart Materials & Structures, 14 (1), 197-214, 2005.
[25] S.W. Yeom and I.K. Oh, "A biomimetic jellyfish robot based on ionic polymer metal composite actuators", Smart Materials & Structures, 18 (8), 085002, 2009.
[26] S. Nemat-Nasser and Y.X. Wu, "Comparative experimental study of ionic polymer-metal composites with different backbone ionomers and in various cation forms", Journal of Applied Physics, 93 (9), 5255-5267, 2003.
[27] J. Wang, C.Y. Xu, M. Taya, and Y. Kuga, "Mechanical stability optimization of Flemion-based composite artificial muscles by use of proper solvent", Journal of Materials Research, 21 (8), 2018-2022, 2006.
[28] T.D. Gierke, G.E. Munn, and F.C. Wilson, "The Morphology in Nafion Perf1uorinated Membrane Products, as Determined by Wide- and Small-Angle X-Ray Studies", Journal of Polymer Science: Polymer Physics Edition, 19, 1687-1704, 1981.
[29] Y. Abe, A. Mochizuki, T. Kawashima, S. Yamashita, K. Asaka, and K. Oguro, "Effect on bending behavior of counter cation species in perfluorinated sulfonate membrane-platinum composite", Polymers for Advanced Technologies, 9 (8), 520-526, 1998.
[30] S. Nemat-Nasser, "Micromechanics of actuation of ionic polymer-metal composites", Journal of Applied Physics, 92 (5), 2899-2915, 2002.
[31] J. Wang, C.Y. Xu, M. Taya, and Y. Kuga, "A Flemion-based actuator with ionic liquid as solvent", Smart Materials & Structures, 16 (2), S214-S219, 2007.
[32] J.W.L. Zhou, H.Y. Chan, T.K.H. To, K.W.C. Lai, and W.J. Li, "Polymer MEMS actuators for underwater micromanipulation", IEEE-ASME Transactions on Mechatronics, 9 (2), 334-342, 2004.
[33] C.K. Chung, P.K. Fung, Y.Z. Hong, M.S. Ju, C.C.K. Lin, and T.C. Wu, "A novel fabrication of ionic polymer-metal composites (IPMC) actuator with silver nano-powders", Sensors and Actuators B-Chemical, 117 (2), 367-375, 2006.
[34] P.G. Gennes, K. Okumura, M. Shahinpoor, and K.J. Kim, "Mechanoelectric effects in ionic gels", Europhysics Letters, 50 (4), 513-518, 2000.
[35] M. Shahinpoor and K.J. Kim, "The effect of surface-electrode resistance on the performance of ionic polymer-metal composite (IPMC) artificial muscles", Smart Materials & Structures, 9 (4), 543-551, 2000.
[36] K.J. Kim and M. Shahinpoor, "Ionic polymer-metal composites: II. Manufacturing techniques", Smart Materials & Structures, 12 (1), 65-79, 2003.
[37] N. Fujiwara, K. Asaka, Y. Nishimura, K. Oguro, and E. Torikai, "Preparation of gold-solid polymer electrolyte composites as electric stimuli-responsive materials", Chemistry of Materials, 12 (6), 1750-1754, 2000.
[38] M. Shahinpoor and K.J. Kim, "Novel ionic polymer-metal composites equipped with physically loaded particulate electrodes as biomimetic sensors, actuators and artificial muscles", Sensors and Actuators A-Physical, 96 (2-3), 125-132, 2002.
[39] B. Akle, S. Nawshin, and D. Leo, "Reliability of high strain ionomeric polymer transducers fabricated using the direct assembly process", Smart Materials & Structures, 16 (2), S256-S261, 2007.
[40] S.J. Kim, I.T. Lee, H.Y. Lee, and Y.H. Kim, "Performance improvement of an ionic polymer-metal composite actuator by parylene thin film coating", Smart Materials & Structures, 15 (6), 1540-1546, 2006.
[41] J. Barramba, J. Silva, and P.J.C. Branco, "Evaluation of dielectric gel coating for encapsulation of ionic polymer-metal composite (IPMC) actuators", Sensors and Actuators A-Physical, 140, 232-238, 2007.
[42] S.J. Kim, C. Cho, and Y.H. Kim, "Polymer packaging for arrayed ionic polymer-metal composites and its application to micro air vehicle control surface", Smart Materials & Structures, 18 (11), -, 2009.
[43] S.D. Pandita, H.T. Lim, Y.T. Yoo, and H.C. Park, "The actuation performance of ionic polymer metal composites with mixtures of ethylene glycol and hydrophobic ionic liquids as an inner solvent", Journal of the Korean Physical Society, 49 (3), 1046-1051, 2006.
[44] M.D. Bennett and D.J. Leo, "Ionic liquids as stable solvents for ionic polymer transducers", Sensors and Actuators A-Physical, 115 (1), 79-90, 2004.
[45] B.J. Akle, M.D. Bennett, and D.J. Leo, "High-strain ionomeric-ionic liquid electroactive actuators", Sensors and Actuators A-Physical, 126 (1), 173-181, 2006.
[46] K. Kikuchi and S. Tsuchitani, "Nafion (R)-based polymer actuators with ionic liquids as solvent incorporated at room temperature", Journal of Applied Physics, 106 (5), -, 2009.
[47] J.W. Lee and Y.T. Yoo, "Anion effects in imidazolium ionic liquids on the performance of IPMCs", Sensors and Actuators B-Chemical, 137 (2), 539-546, 2009.
[48] M. Shahinpoor and K.J. Kim, "Ionic polymer-metal composites: III. Modeling and simulation as biomimetic sensors, actuators, transducers, and artificial muscles", Smart Materials & Structures, 13 (6), 1362-1388, 2004.
[49] D. Pugal, K. Jung, A. Aabloo, and K.J. Kim, "Ionic polymer-metal composite mechanoelectrical transduction: review and perspectives", Polymer International, 59 (3), 279-289, 2010.
[50] S. Tadokoro, S. Yamagami, T. Takamori, and K. Oguro. "Modeling of Nafion–Pt composite actuators (ICPF) by ionic motion", Proc. SPIE, 3987, 92-102, 2000.
[51] K. Mallavarapu and D.J. Leo, "Feedback control of the bending response of ionic polymer actuators", Journal of Intelligent Material Systems and Structures, 12 (3), 143-155, 2001.
[52] N. Bhat and W.J. Kim, "Precision force and position control of an ionic polymer metal composite", Proceedings of the Institution of Mechanical Engineers Part I-Journal of Systems and Control Engineering, 218 (I6), 421-432, 2004.
[53] S. Kang, J. Shin, S.J. Kim, H.J. Kim, and Y.H. Kim, "Robust control of ionic polymer-metal composites", Smart Materials & Structures, 16, 2457-2463, 2007.
[54] K. Yun and W.J. Kim, "Microscale position control of an electroactive polymer using an anti-windup scheme", Smart Materials & Structures, 15 (4), 924-930, 2006.
[55] H.H. Lin, B.K. Fang, M.S. Ju, and C.C.K. Lin, "Control of Ionic Polymer-Metal Composites for Active Catheter Systems via Linear Parameter-Varying Approach", Journal of Intelligent Material Systems and Structures, 20 (3), 273-282, 2009.
[56] R. Kanno, S. Tadokoro, T. Takamori, M. Hattori, and K. Oguro. "Linear approximate dynamic model of an ICPF (ionic conducting polymer gel film) actuator", Proc. IEEE International Conference on Robotics and Automation, 219-225, 1996.
[57] K.M. Newbury and D.J. Leo, "Linear electromechanical model of ionic polymer transducers - Part I: Model development", Journal of Intelligent Material Systems and Structures, 14 (6), 333-342, 2003.
[58] K.M. Newbury and D.J. Leo, "Linear electromechanical model of ionic polymer transducers - Part II: Experimental validation", Journal of Intelligent Material Systems and Structures, 14 (6), 343-357, 2003.
[59] S.X. Guo, T. Fukuda, and K. Asaka, "A new type of fish-like underwater microrobot", IEEE-ASME Transactions on Mechatronics, 8 (1), 136-141, 2003.
[60] K. Takagi, M. Yamamura, Z.W. Luo, M. Onishi, S. Hirano, K. Asaka, and Y. Hayakawa, "Development of a rajiform swimming robot using ionic polymer artificial muscles", 2006 IEEE/RSJ International Conference on Intelligent Robots and Systems, Vols 1-12, 1861-1866, 2006.
[61] Y.F. Shan and K.K. Leang, "Frequency-weighted feedforward control for dynamic compensation in ionic polymer-metal composite actuators", Smart Materials & Structures, 18 (12), 1-12, 2009.
[62] J. Brufau-Penella, K. Tsiakmakis, T. Laopoulos, and M. Puig-Vidal, "Model reference adaptive control for an ionic polymer metal composite in underwater applications", Smart Materials & Structures, 17 (4), 1-9, 2008.
[63] N.T. Thinh, Y.S. Yang, and I.K. Oh, "Adaptive neuro-fuzzy control of ionic polymer metal composite actuators", Smart Materials & Structures, 18 (6), 1-12, 2009.
[64] K.M. Newbury, Characterization, Modeling, and Control of Ionic Polymer Transducers, Ph.D. Thesis, Virginia Polytechnic Institute and State University, 2002.
[65] C. Bonomo, L. Fortuna, P. Giannone, and S. Graziani, "A method to characterize the deformation of an IPMC sensing membrane", Sensors and Actuators A-Physical, 123-24, 146-154, 2005.
[66] Z. Chen, Y.T. Shen, N. Xi, and X.B. Tan, "Integrated sensing for ionic polymer-metal composite actuators using PVDF thin films", Smart Materials & Structures, 16 (2), S262-S271, 2007.
[67] Z. Chen, K.Y. Kwon, and X.B. Tan, "Integrated IPMC/PVDF sensory actuator and its validation in feedback control", Sensors and Actuators A-Physical, 144 (2), 231-241, 2008.
[68] C. Bonorno, P. Brunetto, L. Fortuna, P. Giannone, S. Graziani, and S. Strazzeri, "A tactile sensor for biomedical applications based on IPMCs", IEEE Sensors Journal, 8 (7-8), 1486-1493, 2008.
[69] A.v.d. Hurk, X.J. Chew, K.C. Aw, and S.Q. Xie. "A rotary joint sensor using ionic polymer metallic composite", SPIE, 2009.
[70] A. Punning, A. Kruusmaa, and A. Aabloo, "Surface resistance experiments with IPMC sensors and actuators", Sensors and Actuators A-Physical, 133 (1), 200-209, 2007.
[71] A. Punning, M. Kruusmaa, and A. Aabloo, "A self-sensing ion conducting polymer metal composite (IPMC) actuator", Sensors and Actuators A-Physical, 136 (2), 656-664, 2007.
[72] G.O. Mallory and J.B. Hajdu, Electroless Plating - Fundamentals and Applications, William Andrew Publishing/Noyes, 1990.
[73] T. Osaka, T. Misato, J. Sato, H. Akiya, T. Homma, M. Kato, Y. Okinaka, and O. Yoshioka, "Evaluation of substrate (Ni)-catalyzed electroless gold plating process", Electrochemical Society, 147 (3), 1059-1064, 2000.
[74] M. Kato, J. Sato, H. Otani, T. Homma, Y. Okinaka, T. Osaka, and O. Yoshioka, "Substrate (Ni)-catalyzed electroless gold deposition from a noncyanide bath containing thiosulfate and sulfite - I. Reaction mechanism", Electrochemical Society, 149 (3), C164-C167, 2002.
[75] N. Shaigan, S.N. Ashrafizadeh, M.S.H. Bafghi, and S. Rastegari, "Elimination of the corrosion of Ni-P substrates during electroless gold plating", Electrochemical Society, 152 (4), C173-C178, 2005.
[76] R.C. Hibbeler, Mechanics of materials, 4th ed., Prentice Hall, 572-573, 2000.
[77] K.J. Astrom and B. Wittenmark, Adaptive Control, 2nd ed., Addison-Wesley, 1995.
[78] L. Ljung, System identification. Theory for the user, 2nd ed., Prentice Hall PTR, 1999.
[79] P. Ioannou and J. Sun, Robust Adaptive Control, Prentice Hall, 2003.
[80] J. Fraden, Handbook of modern sensors, Springer, 66-46, 2003.