1. Advances in Controllable ER Fluid Technology, 2010-2012 Smart Structures and Systems Laboratory Department of Mechanical Engineering INHA University, Incheon, 402-751, KOREA http://www.ssslab.com Seung-Bok Choi Inha Fellow Professor Smart Structures and Systems Laboratory National Research Laboratory INHA University

2. Smart Structures and Systems Laboratory National Research Laboratory INHA University Contents Research Works on New ER Fluids Improvement of ER Fluid Properties Practical Maturity of ER Fluid Technology 23 4 1 Innovative Applications of ER Fluids

3. I. Research Works on New ER Fluids Smart Structures and Systems Laboratory National Research Laboratory INHA University

4. Smart Structures and Systems Laboratory National Research Laboratory INHA University Research Works on New ER Fluids (1)  Graphene Oxide Coated Core-Shell Structured Polystyrene Microspheres and Their Electrorheological Characteristics under Applied Electric Field, H. J. Choi et al., Journal of Materials Chemistry, Vol. 21, 2011. Dynamic yield stress vs. electric field strength for 15 wt% core–shell structured PS/GO nanocomposite based ER fluid. Synthesis mechanism of polystyrene–graphene- oxide core–shell structured nanocomposite.

5. Smart Structures and Systems Laboratory National Research Laboratory INHA University Research Works on New ER Fluids (2)  Smart monodisperse polystyrene/polyaniline core-shell structured hybrid microspheres fabricated by a controlled releasing technique and their electro-responsive characteristics, H. J. Choi et al., Journal of Materials Chemistry, Vol. 21, 2011. Schematic diagram of PS/PANI microsphere preparation. The yield stress ( ) as a function of applied electric field strength ( ).

6. Smart Structures and Systems Laboratory National Research Laboratory INHA University Research Works on New ER Fluids (3)  Lanthanum titanate nanoparticles ER fluids with high performance, D. Wang et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010. Yield stress of ER fluid for the LTO powder dried at 80 ° and 120 ° with the volume fraction about 60%. The current densities of the samples are shown in the inset. TG curve of 80 ° and 120 ° dried particles. CC C C

7. Smart Structures and Systems Laboratory National Research Laboratory INHA University Research Works on New ER Fluids (4)  Novel electrorheological fluids with polymer particles containing organic dopants, Y. Reichert et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010. Dynamic yield stress vs. electric field strength for 15 wt% core–shell structured PS/GO nanocomposite based ER fluid. Surface of PUR particles containing a softening organic modifying agent.

8. Smart Structures and Systems Laboratory National Research Laboratory INHA University Research Works on New ER Fluids (5)  Synthesis of titanate/polypyrrole composite rod-like particles and role of the conducting polymer on electrorheological efficiency, M. Mrlik et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  Influence of alkyl chain length on carboxyl-group-immobilized hollow polyaniline spheres dispersed suspension under an electric field, Y. G. Ko et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  ER-activity of suspensions based on hydrated metal oxides, E. V. Korobko et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  Preparation and electrorheological effect of acetamide-modified titanate nanotube suspensions instructions, Y. cheng et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  Electrorheological properties of amorphous titanium oxide particles with different sizes, F. Liu et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  Colloidal graphene oxide/polyaniline nanocomposite and its electrorheology, H. J. Choi et al., Chemical Communications, Vol. 46, 2010.  Core-Shell Structured Semiconducting PMMA/Polyaniline Snowman-like Anisotropic Microparticles and Their Electrorheology, H. J. Choi et al., Langmuir, Vol. 26, 2010.

9. II. Improvement of ER Fluid Properties Smart Structures and Systems Laboratory National Research Laboratory INHA University

10. Smart Structures and Systems Laboratory National Research Laboratory INHA University Improvement of ER Fluid Properties (1)  Wear Characteristics Under Boundary Lubrication Contacts in Phosphorated Starch Based ER Fluids, S. B. Choi et al., Tribology Transactions, Vol. 53, 2010. Wear rate with various specimens after test with ER fluid (normal load = 66.6 N, linear velocity = 0.7 m/s). Experimental apparatus for wear test.

11. Smart Structures and Systems Laboratory National Research Laboratory INHA University Improvement of ER Fluid Properties (2)  Understanding electric interactions in suspensions in gradient AC electric frields I:experimental, Y. Shen et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010. (a):Cross section view of the spatially periodical electrode array in the DEP chamber. (b):Top view of the electrode array. (c):Distribution of the square of electric field strength ( ) in the calculation domain 7.2x3.6x3.0 mm. HV and G denote the high voltage electrode and ground electrodes respectively. There is the lowest electric field at (X, 0, 1.245 mm) or (X, 7.2, 1.245 mm).

12. Smart Structures and Systems Laboratory National Research Laboratory INHA University Improvement of ER Fluid Properties (3)  The effect of compatibility of suspension particles with the oil medium on electrorheological efficiency, M. Stenicka et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010. The shear stress,  vs. shear rate, g, dependence of PANI suspensions in 5 vol% (a), 10 vol% (b) and 20 vol% (c) at the electric field strength,. The shear stress,  vs. shear rate, g, dependence of PANI suspensions in 5 vol% (a), 10 vol% (b) and 20 vol% (c) in the absence of electric field. P1  P2  P3  P4 P1  P2  P3  P4

13. Smart Structures and Systems Laboratory National Research Laboratory INHA University Improvement of ER Fluid Properties (4)  Characterisation of step response time and bandwidth of electrorheological fluids, M. Gurka et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010. Frequency sweep measurements of the pressure drop amplitude and phase shift in flow mode at 10000s and two different temperatures.

14. Smart Structures and Systems Laboratory National Research Laboratory INHA University Improvement of ER Fluid Properties (5)  A note to secondary electrorheological patterns, M. Stenicka et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  Wall slip effects measuring the rheological behavior of electrorheological (ER) suspensions, S. Schneider, Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  Electrorheological response measured with pectinated electrodes, R. Shen et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  Electrorheology of dispersions of BaXSr TiO in silicone oil under AC or DC electric field, G. M. S. Luz et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  Multiple scattering approaches on the electrorheological fluids, G. Sun et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  Theoretical analysis on electro adhesive effect of ER gel, Y. Naito et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010. (1-x)3

15. III. Innovative Applications of ER Fluids Smart Structures and Systems Laboratory National Research Laboratory INHA University

16. Smart Structures and Systems Laboratory National Research Laboratory INHA University Innovative Applications of ER Fluids (1)  Torque Control of a New Haptic Master for Surgical Robot System Featuring Electrorheological Fluid Based Spherical joint, S. B. Choi et al., advanced science letters, 2012(in press). Sinusoidal tracking control trajectory of rolling motion. (a)Tracking Result (b)Control Input. Photograph of haptic master device. Force Sensor Gimbal Guidance ER Spherical Joint AC Motor (a) (b)

17. Smart Structures and Systems Laboratory National Research Laboratory INHA University Innovative Applications of ER Fluids (2)  Development of a compact braille display using diaphragm actuators controlled by ER valves, T. Tsujita et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010. Time history of actuator displacement.Mechanism of a micro-diaphragm actuator.

18. Smart Structures and Systems Laboratory National Research Laboratory INHA University Innovative Applications of ER Fluids (3)  Pump using nematic liquid crystalline flow under application of electric field, T. Tsukiji et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010. Relation between pressure and flow rate for constant voltages. Experimental results. Electrode and channel of pump.

19. Smart Structures and Systems Laboratory National Research Laboratory INHA University Innovative Applications of ER Fluids (4)  High-speed switching control of 1DOF manipulator using ER clutch, M. Yoshikawa et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010. Results of the arm reveral experiments.Experimental apparatus using the soft manipulator.

20. Smart Structures and Systems Laboratory National Research Laboratory INHA University Innovative Applications of ER Fluids (5)  Design and Control of Electrorheological Suspension Using Fuzzy Moving Sliding Mode Control, S. B. Choi et al., Advanced Science Letters, Vol. 4, 2011.  Damping force prediction of electrorheological fluid damper using an analytical dynamic model, S.B. Choi et al., International Journal of Vehicle Design(IJVD), Vol. 56, 2011.  Development of tactile display device using ERG multiple-disk clutch, Y. Urakami et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  Stabilizing output of ER gel linear actuator, K. Koyanagi et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.  The study of auto ABS performance and control based on electrological effect, S. Chen et al., Proceedings of the 12th International Conference on ER Fluids and MR Suspensions, World Scientific Publisher, 2010.

21. IV. Practical Maturity of ER Fluid Technology Smart Structures and Systems Laboratory National Research Laboratory INHA University

22. Smart Structures and Systems Laboratory National Research Laboratory INHA University Practical Maturity of ER Fluid Technology Possible Application Products  Shock Absorber  Haptic Master  Tactile Display  Clutch and Brake  Mount System  High Input Voltage(kV/mm)  Low Field-Dependant Yield Stress(~3kPa)  Narrow Temperature Range(0C~120C)  Low Durability due to Soft Particles  High Sensitive to Chemical Reaction Problems and Issues These should be resolved for practical applications (3~5 Years)

23. Smart Structures and Systems Laboratory National Research Laboratory INHA University