Lightweight composite materials in transportation reduce vehicle weight, which can have a large impact on improving fuel efficiency and reducing CO2 emissions. “The ecological impact of lightweight innovations is one of the key steps in green technologies, and sustainable manufacturing to transform these materials into components and assemble them in a final product are sorely needed,” said Miki Banu, ME research associate professor.
Banu’s research focuses primarily on lightweight materials, with emphasis on developing micro- and nano-cellulose composites, natural fiber composites and associated manufacturing processes for automotive and aerospace applications. Spanning the macro-scale to the nano-scale, her research aims to synthesize new materials with enhanced mechanical properties and high formability. Her research activities include experimental work, multi-scale modeling of materials and simulation of forming processes.
HARVESTING THE BENEFITS OF BAMBOO
“The ability to use tried and true metal forming processes such as stamping on new composite materials, especially green composites, has the potential to speed the adoption of lightweight materials in automotive and other applications,” said Banu.
Banu makes this observation from her extensive research experience and achievements in the area of metal forming of lightweight materials and the development of new lightweight composite materials. Banu joined the U-M ME department in 2013. “Coming to U-M is enabling me to combine my knowledge in materials science and manufacturing and take it toward sustainable and green manufacturing,” she said.
At U-M, Banu joined forces with ME Professor S. Jack Hu and in 2013 created a remarkable patented composite material made from structural bamboo fibers and a polymer matrix.
“Bamboo is one of the strongest natural materials, but it was also interesting to us because it's environmentally friendly – it absorbs a lot of carbon dioxide from the environment – and it grows fast," Banu said.
The new material contains natural bamboo fibers – a green and ecologically beneficial component – and it is 40 percent lighter than glass fiber composites. It's also stronger in flexural strength than carbon fiber composites, and it is cheaper.
Banu won a Michigan Translational Research and Commercialization (MTRAC) award with Hu as co-principal investigator for translating this technology for commercialization. In 2014, they co-founded Optimal Materials in Plymouth, Mich., where Banu serves as the company's chief technology officer in residence.
“The skills, the language, and the entire experience of scaling up our technology and presenting it to prospective customers are thrilling, and it's an amazing opportunity to see these new materials in automotive components as well as in use in other sectors," said Banu, who also is working with a major auto manufacturer to create prototype components using the new composite.
Banu's passion for new materials has inspired others. She organizes the Biocomposites session for the American Society for Composites Conferences, and t events helped spark connections across campus, too. A team of like-minded entrepreneurs from the Taubman College of Architecture engaged Banu in the creation of unique sports equipment for professional athletes. They started by creating a team of ME and Materials Science and Engineering students -- some in their senior capstone design class – who used the new material to build a lightweight hockey sledge.
MODELING MANUFACURING PROCESSES FOR NEXT-GENERATION TRANSPORTATION SYSTEMS
Banu has developed finite element models to optimize forming technologies of lightweight metals and composites to make them cost effective. Her research group focuses on development of models to predict the behavior of aluminum during forming to optimize the process and achieve higher accuracy in the resulting formed components. She explores the most advanced metal forming processes for low volume production. Application areas include aerospace and prototyping, such as by incremental forming, a new and unconventional manufacturing method that does not require dies. Flexible and low cost compared to conventional processes, this approach allows fast fabrication of complex configurations.
Almost immediately upon arriving at U-M, Banu began work with ME Professor Alan Taub on a competitive proposal to establish a large research consortium focused on lightweight materials. The proposal subsequently was selected by the Department of Defense as part of the National Network for Manufacturing Innovation.
Today, Banu serves as technology portfolio manager of the resulting $148 million American Lightweight Materials Manufacturing Innovation Institute (subsequently renamed LIFT), based in Detroit, sponsored by the Detroit Office of Naval Research. Banu's role dovetails with her research, including her work on incremental forming.
Her work was recognized by Boeing, which now sponsors a $2.8 million LIFT project in incremental forming, with Banu serving as principal investigator for the U-M team. Her work will focus on incremental forming for complex advanced aluminum shapes.
“Modeling is a cost effective tool to optimize an early stage process to become available at industrial scale," she said. "Incremental forming is a very flexible process, and it's reconfigurable. We can change the profile of each component, which is important in sectors such as aerospace that need to produce smaller numbers of components for equipment – say a military aircraft – that has a long life."
Within the GM-UM Collaborative Research Laboratories - Advanced Vehicle Manufacturing, Banu creates models and designs new methods for joining lightweight materials. A first application is ultrasonic welding of lithiumi-ion battery tabs, as published in the Journal of Manufacturing Science and Engineering.