Introduction to Smart Materials

Transcription

1 M Smart Materials and Design Introduction to Smart Materials March 2, 2017 Prof. Sung-Hoon Ahn ( 安成勳 ) School of Mechanical and Aerospace Engineering Seoul National University ahnsh@snu.ac.kr 1

2 Outline Introduction to smart materials Introduction to composite Introduction to shape memory effect and shape memory alloy Introduction to electro-active polymer Application examples of smart materials to engineering

3 Course information Instructor Prof. Sung-Hoon Ahn, Director of Innovative Design and Integrated Manufacturing (IDIM) lab Textbook and references 1. Issac M. Daniel, Engineering Mechanics of Composite Materials 2. Ronald F. Gibson, Principles of Composite Material Mechanics, McGraw-Hill Dimitris C. Lagoudas, Shape Memory Alloys, Springer 4. K. Otsuka and C. M. Wayman, Shape Memory Materials, Cambridge 5. Kwang J. Kim and Satoshi Tadokoro, Electroactive Polymers for Robotic Applications, Springer Class schedule Refer to the hard copy TA Ho-jin Kim, Room Yingjun Quan, Room Notice Agreement of collect personal information (picture, name, department) Agreement of Non-Disclosure 3

4 2017 spring smart materials and design Grade Category Percentage Attendance 20 % Homework 20 % 1 st presentation 10 % 2 nd presentation 10 % Term project 3 rd presentation 10 % 4 th presentation 30 % Total 60 % (50%+10% internal evaluation) Total 100 % Individual contribution will be included in term project 4

5 Issues to be covered in this class Composite Analysis of lamina Classical lamination theory Manufacturing processes Shape memory effect (SME) and shape memory alloy (SMA) Fundamental theory of shape memory alloy Thermomechanical characteristics and constitutive modeling SMA fabrication processes Design of SMA and its applications Electroactive polymer (EAP) Fundamental theory and types of EAP Design and fabrication processes of EAP Piezoelectric materials (PZT) Introduction to PZT materials 5

6 APPLICATIONS Of Smart materials Spacecraft Biomedical Automobile Electronics Sports / QoLT Fencing wear Robotics and biomimetics Architecture and structural health monitoring

7 NASA morphing aircraft 7

8 NASA morphing wing 8

9 BMW morphing car 9

10 BMW Unveils Shape-Shifting Car 10

11 Nokia phone 11

12 RoboBee micro air vehicle 12

13 Nitinol stent deployment 13

14 Head piezoelectric ski 14

15 Bridge structural health monitoring 15

16 Turtle Mimetic IDIM lab 15

17 Soft robotic gripper and wrist Gripper with hinged fingers Wrist and curved IDIM lab 17

18 Deployable soft composite structures Wang, W., Rodrigue, H., Ahn, S. H. Deployable Soft Composite Structures. Sci. Rep. 6, (2016). 18

19 4D Printed SMP (Shape Memory Polymer) 19

20 Big Hero 20

21 Smart materials introduction - Classification of Smart Materials Smart materials Shape memory materials Electroactive polymers Piezoelectric materials Shape memory alloys Ionic EAP Electronic EAP Piezoceramics Shape memory polymers Ionic gels Ferroelectric polymer IPMC Dielectric EAP Conducting polymer Electrostrictive graft elastomers Electrorheolo gical fluids Liquid crystal elastomers 21

22 Comparison of Smart Materials PZT actuated RoboBee wing (120 Hz) 20 Hz IPMC artificial muscle slowly oscillating at Hz SMA based high frequency actuator Characteristics SMA IPMC PZT Voltage (V) Low (>2) Low (>1) High (>100) Strain (%) Medium (>5) Large (>40) Small (0.2) Stress (MPa) Large (>200) Low (0.3) Large (110) Actuation Frequency (Hz) Slow (~20) Fast (<100) Very Fast (~10,000) Wood R, Nagpal R, Wei G Y. Flight of the Robobees. Scientific American, 2013, 308(3):

23 Development of AUVs (Autonomous Underwater Vehicles) Biomimetic swimming robots Mechanical linkages are required to achieve complex motion of nature Mechanical linkages are heavy and stiff AQUA (2004) 17 DC servomotors, 30W 3 DC servomotors, 30W 6 DC servomotors, 36W Galatea (2009) AquaPenguin (2009) (pectoral fin) Jellyfish, Virginia Tech (2012) Soft octopus robot (2014) Invisible underwater robot, MIT (2017) (tendon driven, motor based) Biomimetic swimming robots using conventional actuators (motors and pistons) 22

24 Comparison of Actuation Method for Underwater Robots 15 Motor AquaPenguin (2009) 3 DC servomotors 26 IDIM turtle robot 11,16 Smart Actuator , , ,58, , Chu W. S., et al. Review of biomimetic underwater robots using smart actuators. International Journal of Precision Engineering and Manufacturing, 2012, 13(7):

25 Shape Memory Alloy (SMA) Shape memory alloy Metallic alloys that undergo a solid-to-solid phase transformation which can exhibit large recoverable strains. Example: Nitinol. Phase transformation of SMA M f : Martensite finish temperature M s : Martensite start temperature A s : Austenite start temperature A f : Austenite finish temperature T Cooling s Detwinning Heating/Recovery Shape memory effect e s s Mf s Ms s As s Af Pseudoelastic effect e Shape memory effect Pseudoelastic effect SMA Spring vs Hot Water 25

26 Shape Memory Alloy (SMA) SMA coil spring actuator Working principle Manufacturing Working principle Simple manufacturing system enables the fabrication of long strand coiled springs of NiTi muscle fiber. The core wire is under tension and an NiTi wire is wound around the core. The guidance tube is slightly larger than the core wire. The tension of the NiTi wire is maintained by friction between NiTi and the long bar. Soft autonomous earthworm robot at MIT Seok S, et al. Mechatronics, 2013, 18:

27 SMA based high frequency actuator SMA wire Higher heat dissipation rate The phase changes of SMA wire determine the actuating characteristic of actuator. To increase actuating speed, rapid heating and cooling of SMA wire are required. Decreasing SMA thickness Higher heat dissipation rate Method of increasing heat dissipation rate Fast actuating actuator 26

28 Ionic Polymer-Metal Composite (IPMC) IPMC IPMC consists of an ionic polymer material as a base ion exchange medium and a surface metal electrode to which the electric potential is applied. Bending mechanism of an IPMC By applying a voltage to the metal electrodes, the hydrated cations inside the base ionic polymer are rearranged. This rearrangement then induces a volume change, depending on the direction of the anode. IPMC bending actuator Size: 70 mm X 8 mm Frequency: Hz IPMC biaxial actuator (Lee G-Y et al, 2011) The structure is bar shaped with a square cross section and had four insulated electrodes on its surface. By applying different voltages to these four electrodes, a biaxial bending motion can be induced 28

29 Negative Poisson s ratio Auxetic lattice of multipods Pikhitsa P V, Choi M, Kim H J, et al. Auxetic lattice of multipods. physica status solidi (b), 2009, 246:

30 Origami & Kirigami structure Origami structure & Kirigami structure A traditional art form of paper folding and cutting, has been of increasing interest to mathematicians and engineers morphing structures and energy absorption structures/devices utilizing origami patterns 30

31 EXAMPLES OF PREVIOUS PROJECTS 31

32 Adaptable Tire via the use of SMA Adaptable tire characteristics: For rainy and snowy conditions, sufficient tread pattern is required to maintain the grip with the road. Both tire compound (composed material) and the tread pattern determines the driving capabilities The surface pattern of tire can change using SMA based on condition of road surface 31

33 Morphing wheel for Amphibious vehicle Bi-stable structure with SMA Switch states between two stable positions Expansion : by weight and bi-stable structure (water to ground) Contraction : by SMA wire actuation (ground to water) Operation on ground Operation in water * 2015 class presentation 32

34 Rear Wing for Racecar using SMA Wire Rotating/Bending motions produced by embedded SMA wires to change the rear wing angle of attack 4 5 Rear wing is inclined by 30 degrees using SMA spring SMA spring SMA wires Deflection increased a little using the SMA wires support structure skin (PDMS) bending deflection * 2013 Class presentation 34

35 Power (W) Solar Tracker for Solar Panel Amount of energy harvested can be optimized by following the trajectory of the sun Fixed Rotated Angle of light SMA wire is used as sensor & actuator Increased solar efficiency by 19% * 2013 Class presentation 35

36 Wrist Assistive Device to Prevent CTS A multi-position selfadjustable wrist support system was developed to help prevent Carpal Tunnel Syndrome (CTS). SMA wires are used to adjust individual buckling elements. 8 modes of deformation are possible using 3 channels. * 2013 Class presentation 36

37 Transformable Wheel using Origami Structure-based Morphing Structure A robot based on origami principle that is capable of adjusting its wheel diameter was developed SMA Spring Uses a SMA spring to go from the stretched state to the folded state Stretched state Folded state Results presented at IEEE International Conference of Robotics and Automation (ICRA)

38 Biomimetic Underwater Exploring Robot A cuttlefish-inspired robot with SMA embedded in a matrix was built for underwater exploration. Multiple actuators in a single fin allow complex deformations. 38

39 Team formation Homework #1 : MBTI Test Take personality test and bring the results for next class 1. Select gender 2. Response 60 questions 3. Submit your result to TA (ETL) 39