Depok, July 3, 2025 – The Faculty of Mathematics and Natural Sciences, University of Indonesia (FMIPA UI) once again held an Open Doctoral Promotion Session at the Prof. Dr. G.A. Siwabessy Hall, UI Depok Campus. Dr. Ismadi successfully defended his dissertation entitled “Sisal Fiber Modification to Improve the Physical and Mechanical Characteristics of Small-Scale Wind Turbine Blade Composites”, before the board of examiners. Thanks to his academic achievements and scientific contributions, Dr. Ismadi was declared to have graduated with honors.
In his dissertation, the Doctor of Materials Science, highlighted the potential of natural fibers, especially sisal fibers, as an alternative, environmentally friendly composite reinforcement material for small-scale wind turbine blades.
"This research is motivated by the urgent need for strong, lightweight, and sustainable renewable energy materials in line with Indonesia's national target of 23% in the new and renewable energy (EBT) mix by 2025," said Dr. Ismadi.
Through special chemical treatments and microscopic particle coatings, natural fibers from sisal plants were successfully modified to become stronger and more water-resistant. He used a soda-based cleaning solution (NaOH) and added a layer of titanium particles to improve the fiber structure. As a result, the fiber's water absorption was reduced by almost half, and its strength significantly increased.
The composite material made from modified sisal fiber was then tested for various purposes, one of which was as a small-scale wind turbine blade.
"When tested with various compositions and combined with glass fiber, this material has proven to be very strong, elastic, and has high impact resistance. Furthermore, this material does not easily absorb water and does not change shape, which is important for the turbine to function optimally in various weather conditions," said Dr. Ismadi explaining the reason for choosing a composite material from sisal fiber in the development of the latest generation of wind turbines.
Sisal fiber, derived from tropical plants, according to Dr. Ismadi, has many advantages over synthetic materials such as glass or carbon fiber. Besides being light and strong, this fiber is also environmentally friendly because it comes from a renewable natural resource. The fiber's natural weakness, which is not easily combined with other base materials, has been overcome by titanium particle coating techniques, making it a very promising alternative material for renewable energy technologies.
This open session was chaired by Prof. Dr. rer. nat. Budiawan, Vice Dean for Education, Research, and Student Affairs, FMIPA UI. Acting as promoter was Prof. Dra. Ariadne L. Juwono, M.Eng., Ph.D. from the Department of Physics, FMIPA UI, and Dr. Sasa Sofyan Munawar, S.Hut., M.P. from the National Research and Innovation Agency (BRIN) as co-promoter.
Prof. Ariadne, the promoter, stated, "This research not only provides solutions that impact the performance of wind turbine blades, but also supports Indonesia's clean energy transition vision and the development of green materials based on local resources."
He hopes this research can be further developed on an industrial scale to strengthen national independence in the renewable energy sector, particularly in utilizing wind potential in eastern Indonesia such as Nusa Tenggara and Sulawesi.
