What Drives a Sustainable Future?

When we buy everyday items, most of them are delivered by trucks. When we go out, many of us have taken a bus at least once. The primary power source for automobiles is the engine, but emissions such as carbon dioxide and particulate matter (PM) contribute to environmental pollution, making solutions to these issues an urgent global priority. Professor Akemi Ito from the Faculty of Science and Technology is conducting research aimed at reducing the environmental impact of engines.

Professor Ito’s research focuses on two main areas. The first is lubrication around the engine piston. Her team is working on understanding oil consumption mechanisms and reducing friction losses. An engine consists of numerous components, among which the piston is particularly crucial. It moves back and forth inside a part called the cylinder, compressing fuel and air to generate combustion gases. The explosive force of these gases drives another component called the crankshaft, ultimately generating the power needed to move a vehicle. Therefore, any unnecessary friction or resistance in the piston directly affects the efficiency, performance, and environmental impact of the engine. “Our research aims to make traditional engine emissions cleaner and improve fuel efficiency, thereby reducing environmental impact,” she explains.

Professor Ito’s laboratory possesses unique technology to accurately measure conditions around the piston. They have developed a rotating piston equipped with gap sensors that allow them to measure the shape of the cylinder bore while the engine is in operation. Additionally, they have succeeded in embedding optical fibers into a component called the piston ring to precisely measure the thickness of the lubricating oil on the cylinder surface. “Very few institutions have this kind of measurement technology, so we are often approached by manufacturers. By enabling previously impossible measurements, we hope to help manufacturers develop engines with lower environmental impact.”

The second research focus is on the practical application of hydrogen engines. While electric vehicles (EVs) with batteries are no longer uncommon, battery-powered commercial vehicles such as trucks and buses face challenges related to payload capacity and passenger limits. Other issues include charging time and reliability under extreme conditions. Moreover, Japan’s automotive manufacturers currently possess globally competitive engine and vehicle development technologies. However, if EVs become the dominant technology, engine-related expertise may become obsolete, potentially weakening Japan’s competitive edge. Hydrogen-fueled engines could sustain existing engine technologies while maintaining global development capabilities, making them a promising future power source.

Professor Ito’s research involves developing hydrogen-fueled engines, installing them in vehicles, and conducting various experiments. Collaboration with government agencies, automotive manufacturers, parts suppliers, and energy companies is essential. To facilitate this research, a consortium has been established, led by Tokyo City University and Professor Ito’s laboratory. Their research has already progressed to a point where hydrogen-powered engines are practically viable for four-ton trucks. “One challenge we still face is that the water produced when hydrogen burns can mix with engine oil and cause emulsification. However, with guidance from my mentor, I am working to build a research system that allows us to tackle each issue one by one.”

Beyond the consortium, Professor Ito’s lab maintains numerous connections with industry. They frequently lend piston measurement devices to manufacturers to help them gather data for product development. The lab also actively communicates with researchers worldwide to stay updated on the latest trends and identify necessary research directions. “We collaborate with many people to quickly identify efficient and practical solutions for the industry.”

Professor Ito’s journey into this field began when she enrolled at Tokyo City University (formerly Musashi Institute of Technology) and joined a laboratory specializing in internal combustion engines. Her passion for moving machines, such as cars, trains, and construction equipment, along with encouragement from a high school teacher, led her down this path. “My teacher told me that if I was good at math, I should consider studying engineering. I also wanted to assemble an engine myself, so I chose this lab. When I joined, engine disassembly and assembly were a daily occurrence, and that hasn’t changed even now.”

Tokyo has a high number of trucks and buses on its roads. When asked about the challenges the city faces, Professor Ito said, “Decarbonizing public transportation is an urgent issue. Even if hydrogen-powered buses and trucks become more common, we still need to address the challenge of refueling infrastructure. There are currently very few hydrogen refueling stations for large vehicles, so we must consider how to expand this infrastructure.”

Professor Ito finds the high technological demands of commercial vehicles particularly fascinating. “Trucks, buses, and construction equipment are part of social infrastructure, so I feel that my research directly benefits society. If a problem arises, the consequences can be widespread. That’s why the required technical standards are naturally high, which makes this research exciting.”

Buses and trucks run through the city, supporting people’s daily lives and keeping society moving. Balancing the need to sustain these vital functions with reducing environmental impact is a significant challenge. Professor Ito’s research continues to drive progress toward a more sustainable future.