Additive manufacturing (AM), also known as 3D printing or rapid prototyping, has advanced at a remarkable speed, emerging as a robust technology to substitute existing manufacturing processes in increasingly complex tasks. However, printed parts are typically static and non-adaptive. This technology relates to developing a photo-sensitive polymer resin that exhibits shape memory properties that are suitable for 3D printing via UV curing. The developed shape memory polymer (SMP) also displays robust shape recovery over multiple cycles that meets various industrial needs.
This invention has established and demonstrated several key characteristics:
• Rapid curing characteristics (< 3secs)
• High dimensional accuracy for intricate features
• Tensile strength of SLA-printed SMPs (20.2MPa) were comparable to commercial thermoset Veriflex SMP (23MPa), while the elongation was 82% higher than Veriflex.
• Outstanding durability of over 20 shape memory cycles
This invention is targeted towards applications that require repetitive tasks such as:
1. Wearer-Friendly 3D Printed Orthopaedic Cast with Shape Memory Functionality
• Conformal design of casts for each individuals
• Easy wearing and removal of casts for assessment of wounds
2. Re-usable Molds
• Complicated molds can be removed in its rubbery state at temperature above its glass transition temperature and recover upon reheating to be reused several times
The invention aims to not only overcome the limitations in geometric complexity which traditional methods struggle to achieve, but also expand material processing for new classes of smart and responsive materials for 4D printing.
Tunable shape memory properties in terms of transition temperatures are also achievable through regulating material compositions of the polymer, hence widening the spectrum of materials for more applications.