Shape Memory Polymers (SMPs) - Theory, Properties and Applications

The presentation deals with a basic overview regarding the Theory, Properties and Applications of Shape-memory Polymers (SMPs).
It also discusses concepts such as Shape memory effect, Programming of Polymers and Practical applications of SMPs.

1. Properties and applications of Shape Memory Polymers Nithin Thomas apl. Prof. Dr. Fathollah Varnik, M.Sc. Elias Mahmoudinezhad Zirdehi Interdisciplinary Centre for Advanced Materials Simulation (ICAMS) Ruhr-University Bochum, Germany [email protected] Bochum 23/01/2020

2. Contents What are SMPs? Shape Memory Effect Classification of SMPs Design and Mechanism of SMPs Types of Shape Memory Cycles Comparison between SMPs and SMAs Applications of SMPs Conclusion Original Shape Temporary Shape Recovered Shape

3. What are Shape Memory Polymers (SMPs)? Polymeric smart materials capable of recovering from a deformed (temporary) shape to a memorized (original) shape when triggered by an external stimulus . Original Shape Temporary Shape Recovered Shape Thermally induced Shape Memory Effect in ethylene-vinyl acetate “Mechanisms of the Shape Memory Effect in Polymeric Materials” Xuelian Wu et al. (2013)

4. Shape Memory Effect Shape memory effect (SME) and Shape Change Effect (SCE) “Shape Memory Effect in Polymeric Materials: Mechanisms and Optimization” Ye Zhou et al. (2015) The property by which materials that can ‘ remember ’ what shape they were and return to that shape when some stimulus like heat or light, is applied. A → Temporary State B → Permanent State H → Energy Barrier

5. Shape Memory Effect Response to stimulus of touch in Mimosa Pudica Video by Akshay Marathe , India (2011) Stimulus : a thing that arouses activity or energy in someone or something; a spur or incentive.

6. Shape Memory Polymers : Classification Based on the type of Stimuli induced, SMPs are primarily classified into: Temperature (Thermo-responsive) Chemicals (Chemo-responsive) Light (Photo-responsive)  Mechanical force (Mechano-responsive)

7. Design and Mechanism of SMPs The Shape Memory Cycle consists of 3 Steps Programming Storage Recovery

8. Design and Mechanism of SMPs Heat > T g Apply force Cool Remove Force Reheat Programming Recovery Storage Repeat Shape memory Cycle

9. Design and Mechanism of SMPs Shape Memory Cycle “Shape Memory Polymers”, Ledlein and Kelch . Angew . 2018

10. Types of Shape Memory Cycles

11. Types of Shape Memory Cycles Two-Way Shape Memory Effect exhibited by Liquid Crystal Elastomer(LCE) Video by Christopher Yackacki, “Characterization of Active Shape-Memory Polymers” (2017)

12. Comparison between SMPs and SMAs Comparison between SMPs and SMAs “Shape Memory Polymers”, Nithesh D Nayak (2017) Property SMP SMA Density (g/m 3 ) 0.9-1.25 6-8 Phase Transformation Glass Transition Martensitic Transition Strain (%) Upto 400% Upto 8% Recovery Speed (s) 1s to few min <1s Bio compatibility and degradability Good Poor Condition at high Temperature Soft Hard Condition at low Temperature Hard Soft Cost Cheap Expensive Programming Easy and fast Difficult

13. Applications of SMPs Industrial Applications Heat Shrinking tubing Video by Christopher Yackacki, “Characterization of Active Shape-Memory Polymers” (2017)

14. Applications of SMPs Biomedical Applications A smart surgical suture self-tightening at elevated temperatures “Review of progress in shape-memory polymers”, C. Liu et al. (2007)

15. Applications of SMPs Biomedical Applications SMPs used in Minimum Invasive Surgery Video by Christopher Yackacki, “Characterization of Active Shape-Memory Polymers” (2017)

16. Summary Polymers that can recover their original shape on exposure to an external stimuli is called SMPs. A distinction was made between SME and SMC. SMPs can be classified based on stimuli used for recovery. A Shape memory cycle consists of Programming, storage and recovery. A comparison between SMPs and SMAs were made. SMPs are used in numerous applications.