Shape memory effect in plant leaves

• Main Author: Wong, Shi Chow
• Other Authors: Huang Weimin
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: Engineering::Materials::Biomaterials
• Online Access: http://hdl.handle.net/10356/78781
• Institution: Nanyang Technological University

To date, research are primarily focused on conventional polymers with minimal emphasis on unconventional polymers, such as biopolymers. Thus, the aim of this project is to further investigate the shape memory effect in biopolymers found in plant leaves. In this study, investigations were done on 3 different types of plant leaves, namely: soursop, sugar apple and longan leaves. The leaves were subjected to 2 different programming conditions (rolled around 8 mm and 12 mm diameter rods) and 3 different stimuli (room temperature water, hot water and heat). The results from this study suggest that plant leaves exhibit higher rate of shape recovery when subjected to smaller deformation, when the lamina portion (including cuticular wax) of plant leaf was removed and when submerged into water of higher temperature. Heat was tested and shown to not be a suitable stimulus to initiate shape recovery in plant leaves. Similar to conventional polymer, plant leaf does exhibit shape memory effect in the presence of the right stimulus and the rate of shape recovery is affected by both the programming condition and the composition it is made up of.