Why Film Festival UMFF visited Team ZeF?

In April, Team ZeF from the laboratory of Professor Kim Youngsik of the School of Energy and Chemical Engineering (YK group) received an unusual proposal from the Ulsan Ulju Mountain Film Festival (hereinafter referred to as “UMFF”). As a film festival that focuses on coexistence with nature, and strives to hold eco-friendly events., this year, UMFF planned an ambitious project called the “UMFF Pedal Theater,” which screens movies using bicycle power, emitting zero carbon. They came to Team ZeF to ask for technological expertise. Research Assistant Professor Lee Wang-geun said it was an interesting proposal.
“I was interested because this festival is usually held in our region. I also attend the film festival every year. The project involves people pedaling bicycles to generate eco-friendly energy for screening movies, which sounded very attractive. To stably store and supply the generated energy, the battery system, which is our team’s research area, is essential. I thought it was an opportunity to demonstrate our research knowledge and decided to join the project.”
Eight people participated in the UMFF Pedal Theater project including: Research Assistant Professor Lee Wang-geun, researchers Bae Jun-ho, Lee Seung-min, Jang Jeong-beom, Ju Eun-seo, and Kwon Min-seo, and interns Kim Hyun-jin and Kim Jae-heon. The goal was to convert the energy generated by bicycle power into stable power for movie screenings. They dedicated three months to develop a system for generating and storing energy and video projection equipment using bicycle power, and succeeded in the end.
The principle is as follows: A permanent magnet is attached to the rear wheel of the bicycle, and electricity is generated through the electromagnetic induction within the coil through pedaling. The generated power is then stored in a secondary battery to start the beam projector. It may seem simple, but it is a challenging technology. Additionally, Team ZeF applied their main research technology, a special fire-retardant material and sealant, to create a new type of battery. During normal operation of this battery, the fire-retardant material is inactive, but in emergencies, it immediately penetrates the interior of the battery, thus enhancing safety by fundamentally blocking fire spread.

Battery used outside the laboratory

To start the beam projector, 500W of power is required. To achieve this, 10 bicycles were connected and pedaled at the same time. The UMFF Pedal Theater played a 15-minute-long short film a total of 11 times during the festival from October 21 to 28. The total generation time was about 120 minutes, producing a total of 611Wh of power. In addition to movie screenings, the project garnered significant interest by operating a bubble machine using the power generated by three bicycles, encouraging participation and attention from the audience.
However, there were several challenges before the UMFF Pedal Theater could open. If pedaling becomes weak while generating energy, resulting in a decrease in power, it would be impossible to project movies stably. Furthermore, the power generated would inevitably vary on each of the 10 bicycles depending on individual physical stamina. This could lead to overload on one side, posing a risk of fire. To ensure stable and safe beam projector operation during the 10-15 minute screening time, they developed a device to store the energy generated by the 10 bicycles and a control box for uniform power generation. However, there was an unexpected complication. During the development, researchers had to frequently pedal the bicycles, and the stamina of the researchers, who never exercised and rather accustomed to sitting in the laboratory, became a problem.
After all these challenges, when the UMFF Pedal Theater finally opened, the audience's response exceeded expectations. They recruited about 20 volunteers per session and 10 people pedaled the bicycles at a time. Approximately 160 people participated, ranging from elementary school students to middle-aged adults. Participants willingly joined the UMFF Pedal Theater, saying “It's fulfilling to contribute to the Earth,” “It's fun,” “I'm curious to know how much power is generated,” and “It's fascinating that electricity is produced through the pedals I'm stepping on.”
Even when there were no movie screenings, the audience showed interest in the eco-friendly power- generation device. This reaction from the audience was a refreshing experience for Team ZeF because it was their first encounter with people outside the laboratory. Researcher Bae Jun-ho said, “Participating in a project with ordinary citizens was a new experience after only working on academic research or national and corporate projects. I hope there will be more opportunities to do things with people.” Researcher Jang Jeong-beom said, “It was gratifying to see our battery attracting many participants at a local event outside the laboratory. I hope that the project would serve as an opportunity for people to actively engage in environmentally friendly activities and develop an interest in eco-friendly energy.”

Expectations for more projects

The UMFF Pedal Theater project became an opportunity to inspire in the local community greater interest in eco-friendly technology, and a chance for Team ZeF to shift their focus outside the laboratory. Researcher Ju Eun-seo remarked, “I was glad to be able to contribute to the local community outside the laboratory. Technology is important, but I realized that it is also important to implement it for actual users in different ages and genders to use it conveniently in real-life situations.” Researcher Lee Seung-min added, “I was able to fully understand the principles of electromagnetic induction and power conversion, which I only learned in theory. This was my first time, and I was a little rushed to operate the generator, but if I get another chance, I would like to have time to interact with people, explaining the operation principles and answering questions to make complex scientific theories and environmental issues more approachable.”
Most bicycles and generators were returned to UMFF after the event, but some remained in the laboratory for additional research purposes. Team ZeF plans to further refine their technology and expand its application areas.
“We research batteries. Our goal is to safely store power produced by solar and wind energy, in addition to bicycle-generated power. This project is a good example that demonstrated even unstable power, such as bicycle-generated power, can be reliably stored. I think it was a good opportunity to introduce our research to the local community.”
It seems that Team ZeF will have more opportunities to contribute to the local community and interact with people in the future, as not only UMFF but also local authorities have expressed interest. What kind of project will bring them together next time? Hopefully, Team ZeF will continue to radiate positive energy into the world.