Several Universitas Sumatera Utara (USU) students have developed mask filters that use nanofiber from banana stem waste. The team has submitted a research proposal for the Student Creativity Program (PKM) entitled “Effectivity of Cellulose Acetate Nanofibers from Banana Midrib Waste (Musa paradisiaca L.) as an Anti-bacterial Filter on Masks” and was presented at the 34th National Student Scientific Week (PIMNAS) event in October 2021.
The students, calling themselves the Nanofilter Mask team, consisted of Sylvia Romalia Simanungkalit, Putri Amelia Sihotang, Shofi Tasa Al-Khairi, and Dzul Hadi Sahputra from the Faculty of Mathematics and Natural Sciences (MIPA) Chemistry bachelor degree, and Brian Christopher from the Faculty of Dentistry.
Sylvia, the team leader, said the work was done based on the COVID-19 pandemic, where masks are the main need for the community for self-protection. Moreover, many masks circulating in the market do not meet the World Health Organization (WHO) standards.
“Considering masks are highly crucial and needed, we decided to make a mask filter using nanofiber,” she said. “We studied the method of manufacture from a review of journals, and it turns out that we can do it in the laboratory. The filter we made is anti-bacterial; the nanofiber is tight enough to filter bacteria, increasing the effectiveness of the mask worn.” Sylvia explained.
Banana midrib was chosen as a source of nanofiber because it contains anti-bacterial compounds in the form of flavonoids, alkaloids, phenols, and saponins. The cellulose content in the banana midrib is also considerably high, about 63%. Banana stems were also chosen because they are easy to obtain, especially the Barangan banana species (Musa acuminata), an endemic plant in North Sumatra.
A lecturer supervised Sylvia and her team, Muhammad Zulham Efendi Sinaga S.Si., M.Sc., who helped develop their ideas further into a competitive proposal for the student research grant. The team designed a three-layer filter; the middle layer is made from banana midrib and then processed into alpha-cellulose. Then, it is synthesized into cellulose acetate and made into nanofibers through electrospinning method.
Zulham, as the supervising lecturer, explained that banana midribs are usually discarded because they are considered useless wastes. However, lab testing showed that they contain very high cellulose and possess antimicrobial properties; testing them against staphylococcus and E. coli bacteria showed positive results in bacteria inhibition. The team processed them into a mask filter, which can be inserted into a two-layer cloth mask.
The team stated that the filter from the banana midrib has nano-sized pores that can filter out aerial dirt and even coronavirus droplets, which are about 0.5 microns in size. They will further develop this filter by conducting clinical, pre-clinical, and efficacy trials for breathing difficulties while wearing it. A mask that uses a nano filter with anti-bacterial effectiveness can shield the wearer against bacteria and prevent bacteria from growing. With these capabilities, a cloth mask equipped with this filter can work well like medical masks.
Their hard work paid off; the team won a research grant from the Indonesian Ministry of Education, Culture, Research, and Technology to refine the mask filter further. In the future, the team hopes they can also find funding for manufacture and development so the filters can be distributed to paramedics and the public. Zulham was proud of the team’s achievement and hopes that this can inspire other students to continue to look for ideas from the humblest of sources and the university to support student innovations.