Institut Teknologi Bandung

BANDUNG, itb.ac.id - The Renewable Energy Laboratory Team, Faculty of Mechanical and Aerospace Engineering (FTMD) Bandung Institute of Technology, chaired by Dr. Yuli Setyo Indartono, develops a sterilization cabin for N-95 masks. This cabin is expected to be able to sterilize N-95 masks that already have been used by medical personnel.

The 1x1x2 m3 sterilization cabin is using air ionization and humidity-reducing air technology with N-95 mask sterilization rack. Besides Dr. Yuli, there are some people who involved in this project; Andhita Mustikaningtyas, ST., Musfirin, ST., MT., (Horizon Technology), Mukhlis Ali, ST., MT, (FTMD ITB alumni that working at Nusa Putra University) and Taufik Rahman (a Nusa Putra University student).

Dr. Yuli explained, the aim of N-95 sterilization cabin is to reuse N-95 masks. That’s because during COVID-19 pandemic the demand of N-95 masks is increasing. N-95 is an essensial tool for medical personnel both in hospitals or public health center (puskesmas). On the other hand, the availability of N95 masks for medical personnel is limited.

He continued, based on recommendations from Ministry of Health Republic of Indonesia, mask sterilization can be done in several ways. First, the masks are stored in a paper bag and left for 3-4 days so there is no media for viruses to replicate. Second, the masks can be heated to 70° C in the oven. Third, hot stream exposure. And fourth UV light radiation. The last method is not recommended for mask sterilization because it can damage N-95 mask layer.

"From these various methods, there should be a test-based sterilization method that can destroy bacteria and viruses, without damaging the layer of N-95 mask. So we don't use UV light radiation and hot steam exposure method, "said Dr. Yuli to ITB Public Relations.

In order not to damage the mask layer, the sterilization process is carried out at room temperature. "We use air ionisation technology. From various scientific studies, negative ions can damage bacteria and viruses. We also use a dehumidifier to reduce air humidity. If air humidity is low, the air will absorb water from mask layer. No need to heat the mask." he explained.

Sterilization cabin is at a vacuum state. There are three main components; an air ionizer (it produces hydrogen peroxide), a dehumidifier. and a small fan. There is also a timer to set mask sterilization time. The sterilization process takes about two hours and bacteria decontaminate ability has been tested on Microbiology Laboratory, School of Pharmacy ITB by Prof. Marlia Singgih Wibowo, and Prof. Pingkan Aditiawati from SITH ITB. The test results showed that this sterilization cabin has an ability to decontaminate Staphylococcus aureus and E.coli on mask surface layer as much as 90% for 90 minutes.

On Monday, April 20, 2020 at BPUDL-ITB office, N-95 Sterilization Cabin made by the Renewable Energy Laboratory Team FTMD - ITB was handed over to Hasan Sadikin Hospital Bandung for further testing. RSHS gave a positive reaction towards sterilization cabin. The cabin will be installed and tested directly at RSHS Bandung. Dr. Yuli said there are 8 other hospitals that have sent a request for ITB’s sterilization cabin.

He hopes that sterilization cabin can be useful especially for mask sterilization. The concept of N-95 sterilization cabin can sterilize other various reusable PPE, but the current design is designed for N-95 masks. "Hopefully this cabin will be able to improve N95 mask sterilization method that has been carried out in hospitals," he said.

Reporter: Adi Permana
Translator: Billy Akbar Prabowo