Ibnu Taufan, a PhD researcher at UL, discusses vibration research and his particular interest in a ‘dancing bridge’ phenomenon.

For many researchers, the origins of their interest in a particular scientific area can be traced back to a specific event or place. For Ibnu Taufan, the link can be found in two specific events – the first one involving the longest bridge in Indonesia.

“When I was young, my father and I used to travel from Sumenep (my hometown) to Surabaya (the second largest city after Jakarta) by a ferry. On the ferry, I watched Suramadu Bridge as it was being constructed,” he says.

“It took six years to complete the bridge. I asked my father why it took so long to build the bridge, but without a proper answer.”

The second event can be traced to Taufan’s time studying a degree in engineering physics at the Institut Teknologi Sepuluh Nopember in Surabaya, where he finally got an answer to the question he asked his father.

“The lecturer explained the resonance phenomenon on a bridge. He showed the famous example of Tacoma Bridge, which collapsed due to a resonance phenomenon,” said Taufan. “This bridge has revolutionised vibration research, rendering bridges all over the world safer. He explained and proved the resonance using a simple mathematical model and the physics behind it.

“I loved math and physics in secondary high school, and, due to his explanation, I loved the study of vibrations even more.”

Taufan went on to complete his bachelor’s degree with a specific interest in vibration research, and began a career as a product and development engineer in vibration engineering at a pump manufacturing company in Indonesia.

“Mostly I worked on research about how to utilise vibration signals for machine health monitoring and to reduce excessive motion of structures using vibration control,” he says.

A few years into his career, Taufan was presented with an opportunity to pursue a PhD in vibration energy harvesting at University of Limerick (UL). Interested by this new research direction, Taufan decided to follow up on the opportunity and move to Ireland.

“This topic is fascinating for me because instead of reducing the uncomfortable vibrations (from cars), the goal of this research is to harvest ambient – waste – vibrations from machines into electricity to power Internet of Things (IoT) sensors for Industry 4.0 applications,” he tells SiliconRepublic.com.

“In this context, I am eager to solve vibration research challenges in order to contribute to both industry and society.”

Good vibrations

Taufan’s PhD research topic is to develop a novel broadband piezoelectric vibration energy harvester (PVEH) technology to sustainably power IoT sensors for preventive maintenance and performance optimisation in Industry 4.0.

“Generally, the industry relies on batteries or the electricity grid to power sensors for machine monitoring purposes. However, these types of energy sources are not sustainable and expensive in remote locations,” he explains. “The PVEHs (battery free devices) created in my PhD can harvest ambient vibrations from the machines themselves to sustainably power the IoT sensor for machine health monitoring in real time.”

He says the importance of this research lies in its capability of reducing battery waste and overreliance on the electricity grid.

“Batteries not only contribute to contamination in soil and groundwater due to metal waste during their production, but also the battery waste contains toxic heavy metals which can cause soil and water contamination on residential areas if not correctly disposed of,” says Taufan. “Also, the electricity grid needs physical wires or cables to thousands of remote sensors which would be impractical and expensive.”

Vibrational energy harvester (VEH) technology, he explains, can be employed to power thousands of IoT sensors in remote locations for machine monitoring in Industry 4.0. The IoT sensors can then make the data accessible via the internet to monitor the industrial assets in real time without batteries or electricity connections.

Dancing phenomenon

Within his vibration research, one of Taufan’s favourite topics is resonance, the previously mentioned phenomenon which can cause catastrophic failure in improperly constructed structures such as bridges, buildings, trains and aircraft.

Resonance is defined as a phenomenon which occurs when an external vibration frequency matches with a structure’s natural frequency, causing the amplitude of vibration to increase dramatically – though Taufan has a better (and more fun) way of explaining it.

“In simple terms, if someone loves a specific music (A), he or she will dance when hearing the music they like. However, if he or she hears another music (B) that they do not like, they will not dance.

“The person can be depicted as a structure (bridge), while the music is an external vibration source (such as vibration from vehicles crossing the bridge or vibration due to the wind).

“The dancing phenomenon is the reason why the bridge can collapse.”

Taufan says that as part of his PhD research, he needs to design a harvester – or structure – which has a natural frequency similar to the operational frequency of a machine (ambient vibration).

“Therefore, the harvester will ‘dance’ if I put it on the machine,” he says. “The dancing phenomenon on my harvester will generate high-output power that can sustainably power IoT sensors for machine monitoring in Industry 4.0.

“This is why I love resonance, and the mathematics and physics behind it!”

The future of VEH

Taufan believes that in the near future, battery waste can be reduced significantly due to his research area, and that VEH tech plays “an important role” in Industry 4.0.

“The maintenance engineer in industry will not need to manually monitor machines or replace the batteries of the IoT sensors,” he says. “In railway industry, the VEH can be utilised to monitor railway condition using IoT sensors.

“Vibrations from railway (due to crossing trains) is sufficient to power the sensors – thus, the railway company does not need to conventionally monitor the track, which causes travel disruptions.”

He says some people think VEH can replace batteries in devices like smartwatches because it is perceived that the ambient vibration when we are walking, running or biking could charge the smartwatch using VEH technology.

“In my opinion,” he says, “VEH can partially – but not totally – replace batteries, recharge the rechargeable batteries in our smartwatch. This is because when the total VEH volume is small – such as within a smartwatch – the natural frequencies of the VEH will be higher than 30Hz.

“In this context, the frequency contents of ambient vibrations (from human motions) are below 30Hz. There is still an open challenge to VEH researchers to propose VEHs (with small volume like smartwatches) to power these devices without batteries. “

With his PhD still underway, what lies ahead for this researcher after he completes his studies?

While he’s open to R&D opportunities in industry, Taufan says he plans to stay in academia.

“I love both teaching and research in related to vibration,” he says. “I believe that my expertise and passion in vibration research can contribute to solve many problems related to vibration and sustainability in both industry and society.”

Don’t miss out on the knowledge you need to succeed. Sign up for the Daily Brief, Silicon Republic’s digest of need-to-know sci-tech news.