Friction Nonfiction

By:      Ashley Duvelius
Date:   December 18, 2017

Dr. Woo Kyun Kim, UC mechanical engineer, receives two National Science Foundation awards totaling more than $525K, to address nano-scale machine wear caused by friction and to study graphene as a possible solution.

For a society that is heavily dependent on energy, a fraction of friction makes a world of difference.

Many times, friction is a good thing as it can be used to generate electric energy. But in things like machines, nano-scale friction is a villain—increased friction causes increased wear and tear on machinery, leading to more frequent machine replacements and repairs.  In the latter case, friction is a primary mechanism of energy waste and so, reducing its effects would have a great impact on energy sustainability.

Dr. Woo Kyun Kim

“A study showed that 1.3 - 1.6 % of an industrialized nation’s GDP is lost due to friction. For the US, this corresponds to about $300 billion dollars in 2015. Thus, I want to better understand friction and wear, which will in turn have significant positive impacts on the national economy,” explains Dr. Woo Kyun Kim.

Dr. Kim, University of Cincinnati (UC) College of Engineering and Applied Science (CEAS) Department of Mechanical and Materials Engineering Assistant Professor, serves as Principal Investigator for two National Science Foundation (NSF) awards to gain an enhanced understanding of friction and lubrication solutions that will pave the way for realization of frictionless sliding on macroscopic scales.

Dr. Kim’s first NSF project, entitled “Collaborative Research: Accelerated Large-Scale Simulation Study of Atomic-Scale Wear Using Hyper-Quasicontinum,” totals $201,645.00 and focuses on the nano-scale wear of friction. The grant began in July 2015 and runs through June 30, 2018 (estimated).

His second NSF project, entitled “Accelerated Molecular Dynamics Study of the Role of Crystalline Defects in Friction of 2-Dimensional Materials,” furthers and applies the research findings of his first grant, and is aimed at studying the friction of graphene. This award totals $324,555.00 and runs July, 2017 through June 30, 2020 (estimated).

The ultimate aim of these projects is to develop a novel predictive model for nano-scale wear and furthermore, find a solid lubricant to reduce friction and the nano-wear of devices. Dr. Kim believes graphene would be an ideal solid lubricant as it has thickness on the atomic scale.

Dr. Kim’s research uses computer simulations to investigate material properties and behaviors from the fundamental level. When he investigates friction and wear from the very small scales of atoms, Dr. Kim observes how they move and interact in computer simulations.

Computer simulation model of AFM (atomic force microscope).

Computer simulation model of AFM (atomic force microscope).

Dr. Kim reflects, “I am very excited to be awarded two NSF grants, which is indicative of the national recognition of my research. I'm very confident that these research outcomes—improving lubrication on a microscopic scale to decrease mechanical wear—will benefit society, lead to advances in nanotechnology and will save the US economy up to $241 billion per year.”

Dr. Kim joined the UC CEAS Department of Mechanical and Materials Engineering in 2014. He is originally from South Korea, where he received his master’s degree in Mechanical Engineering at Seoul National University and worked in the New Gasoline Engine Development Team at Hyundai Motor Company. He completed his PhD in Mechanical Engineering at the University of Michigan.