Mimosa pudica : experiment on light stimulation of plant movements

• Main Author: Lai, Zi Yu
• Other Authors: Li Hua
• Format: Final Year Project
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/64084
• Institution: Nanyang Technological University

Mimosa Pudica – the sensitive plant – has been studied since the 18th century when French Geophysicist M. De Mairan was trying to understand the circadian motions of the plant. Over the years, researchers have tried to understand the different behaviours displayed by the plant. Studies ranging from the motions, different stimulation, movements, modelling process and even pharmaceutical uses of the Mimosa Pudica have been explored. It was not until recent years that researchers started to explore the area of plant intelligence. Gagliano M et al found out that even though plants lack organs such as the brain or even neural tissue, they do possess some form of system that signals with complex calcium. In this report, we investigate the effects of the different light colour (white and red) on the leaflet movements. The leaflet folding habitual was observable and pronounced for Mimosa Pudica subjected to intervals of repeated and continual dark and light stimulation, specifically sunlight, white and red LED light. Habituation is often tied together with fatigue life. A positive relationship between the number of stimulation and the response time was found, and eventually reaches a point whereby fatigue life is reached and the plant exhibits reluctance to any further movement. It was also found that the variation in dimensions of the different Mimosa parts have a relationship with the response time. This will be another focus of this report.