Poetry as the building blocks of engineering

Monday, April 10, 2017

Quite the juxtaposition of words, yet exactly those used as inspiration by James Manimala, assistant professor of mechanical and aerospace engineering.

Manimala discovered a correlation between the two subjects while analyzing the poem “I Wandered Lonely as a Cloud” by William Wordsworth. The fourth line of its second stanza reads “A host, of golden daffodils”.

In reflection on that particular phrase, Manimala focused on the long “o” repeated throughout the line and how the subtleness of the sounds impacted the overall effect of the piece. Poets and writers refer to this literary device used as a building block of verse as “assonance.” In that moment, he realized the same principle could be applied to his research in mechanical metamaterials. Just as the soft sound of the long “o” created a desired rhythm, he could make repeated alterations within existing materials to achieve the desired effect he sought.

Manimala’s research focuses on introducing internal features into materials to get a desired transformation across structures. In practical terms, if a host material can be altered through “clever little dynamics” to change the material, then existing materials can be transformed to realize unprecedented dynamic characteristics.

He compares the process to crafting a recipe that has a complicated list of exotic ingredients, but he gets to determine how much of which ingredients to use and in what way to control the flavor of the dish. When applied to metamaterials, this is a groundbreaking approach based on integrating mechanical assonance and inertance. Such metamaterials can steer, focus, disperse or even reject mechanical disturbances and also act as “tuned mass participants”, which have a relatively small static mass but a dynamic mass presence a few orders of magnitude greater. The uniqueness of Manimala’s research is one of the characteristics that sets it apart.

The foundations of his theory were published recently in the Journal of Applied Physics and the Journal of the Acoustical Society of America. The publications led to his receiving the Defense Advanced Research Projects Agency (DARPA) Young Faculty Award, which provides $498,000 over two years with the possibility of a $500,000 follow-on director’s fellowship. DARPA historically funds high-risk, high-payout projects that have the potential to alter the footprint of modern technology.

Due to the nature of DARPA, Manimala’s research will focus on defense applications, including microelectromechanical systems (MEMS). The basic technology of MEMS has existed since the 1980s and has since been utilized for atomic clocks, inertial sensors for missiles and even for micro-robots in biomedical applications. 

Manimala will use his mechanical assonance principle to explore mechanical encryption for crucial military devices. In other words, he will encode the device in a way that can only be decoded through his specific type of signal processed through mechanical assonance. This development, if successful, will transform the way MEMS are used for defense purposes.

Through this project, OSU will partner with such universities as Stanford and Purdue. Manimala’s experiments require highly specialized types of materials and miniaturized manufacturing that are only available at those academic institutions or at national labs such as Sandia. Manimala’s project will also build relationships with a variety of Department of Defense agencies through site visits and communicating with warfighters and defense technologists. He also anticipates working with a handful of national laboratories and defense suppliers due to the specific nature of his research.

Over the course of the two-year project, Manimala and his team will perform experiments on a microscopic level. They will utilize the Solid and Structural Dynamics Lab (SSDL) on OSU’s campus to analyze the effects of vibrations on metamaterials up to the microscale — about the width of a human hair. By the end of the project, Manimala expects to have a device prototype for DARPA to review.

Manimala’s groundbreaking theory also has practical application outside of defense purposes. He says the principle is scalable and can be applied to macroscale areas such as space and nuclear infrastructure as well as the medical field.

In space, Manimala says mechanical assonance can be applied during launch situations where the event is typically forceful and violent.

“When launching a device into space, you need to isolate sensitive payloads from adverse vibrations,” he says. “These payloads have to survive the launch. Assonance-based vibration isolators provide a means to sequester or redirect undesirable mechanical disturbances to protect such valuable assets during their journey into space.”

The same idea is used when considering the applications for nuclear infrastructure. For example, the earthquake and ensuing tsunami that hit Japan in 2011 caused serious concern for the nuclear power plant located on the island. Through the utilization of mechanical assonance, the materials used to build a nuclear power plant could be altered to manipulate and reject the energy of the waves caused by a natural disaster, rendering the structure more secure.

Manimala also recognizes the potential for energy harvesting through his principle. He uses the medical field as an example, specifically ongoing research on pacemakers. These devices are implanted in the body through an invasive surgical procedure. The battery life currently only lasts six to 10 years, meaning someone struggling with a severe health issue must go back under the knife.

Mechanical assonance may provide a solution by creating a harvester that can cope better with fluctuations in the heart’s vibrations. In other words, the human heart is constantly beating and producing kinetic energy but there is variability depending on the heart rate. Manimala’s application of assonant metamaterials within the pacemaker could provide the passive-adaptive stability needed to harvest energy from the person’s beating heart to power the device indefinitely. This technology could drastically change the quality of life for millions of people who live with the device.

Manimala’s theories and his future discoveries promise to bring forth results that will alter the footprint of structural materials. His work at OSU could affect society on a global scale and significantly alter the military, space and energy industries.

Five simple words with three long o’s could be the key to a new era of metamaterials engineering.