Shape memory polymers (SMPs)
Shape memory polymers (SMPs) are a kind of stimuli-responsive smart materials with the ability to undergo a large recoverable deformation upon certain external stimulus, (e.g., heat, electricity, light, magnetism, moisture and chemicals). SMPs possess numerous technical advantages compared with shape memory alloys including high recoverable strains, ease of processing, the ability to tailor the recovery temperature, programmable and controllable recovery behavior, low cost and light-weight, etc. Combining such advantages with the smart shape memory behavior, SMPs presents significant potential and practical applications in various important fields.
Fig. 1 Schematic of shape memory effect during a typical thermo-mechanical cycle
In our group, we focus on:
(a) Fabrication of various kinds of SMPs with different glass transition temperatures (Tg), including:
Table1. Types of Shape Memory Polymers
Thermosetting SMPs | Tg (℃) | thermoplastic SMPs | Tg (℃) |
Polyimide Cynate Styrene Epoxy Bismaleimide | 90-320 160-250 47-88 100-188 95-123 | Poly (ε-caprolactone) Polyurethane Poly(arylene ether ketone)s Chitosa | 37-46 27-45 116-140
61-63 |
We can provide diverse SMPs with different Tg for future collaborations.
(b) Investigation of the actuation approaches of SMPs and their composites, including:
· Thermal-actuated method
· Electrical-actuated method
· Light-actuated method
· Magnetic-actuated method
· Solvent-actuated method
· Multistage-actuated method
Fig. 2 Thermal-actuated SMPs shape recovery process in 60 ℃ water
Fig. 3 Electrical-actuated SMPs shape recovery process at 30 V
Fig. 4 Light-actuated SMPs. (a) Wavelength-selective shape memory structures based on PAEK/CA, PAEK, and PAEK-ABZ components; (b) Smart man and (c) Flower with their diverse customized actions
Fig. 5 Magnetic-actuated SMP. (a) Real process;(b)Shape recovery behavior of 4D printed structures with 15% Fe3O4 at 27.5kHz
Fig. 6 Solvent-actuated SMPs with 3D microvoid is designed based on chemical interaction
Fig. 7 Multistage-actuated SMPs.(a) in 34℃, 37℃ and 41℃ temperature, respectively; (b) in an alternating magnetic field with a frequency of 20 kHz and a field strength of 6.8 kA m-1 and (c) in the supplied voltage 60 V
(c) Exploration of the potential and practical applications of SMPs and their composites in various fields, including:
· Deployable structures
· Morphing structures
· Medical devices
· Foams
· Smart mandrel
· Self-healing systems