Green Limerick: Breakthrough on eco-friendly energy

RESEARCHERS at the University of Limerick (UL) have developed a new method of growing organic crystals that can be used for energy-harvesting applications.

This energy method, developed by the research team from the Actuate Lab in the Department of Chemical Sciences and Bernal Institute at UL, offers a low-cost and eco-friendly alternative to the conventional method of making piezoelectricity.

Piezoelectricity, which translates from Greek to mean pressing electricity, is usually found in ceramics or polymers and is also present in human biomolecules.

The energy that is being harvested as part of this research is being generated by squeezing amino acid molecules, which are the building blocks of proteins that exist in the human body.

If successful, the research undertaken by the team at UL has the potential to remove environmentally damaging materials, such as lead, from consumer electronics.

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Discussing this latest breakthrough, the lead author of the paper and PhD student at UL, Krishna Hari, explained: “The versatile moulding technique that we have developed is a low-cost, low-temperature growth method, that opens the path to phase in biomolecular piezoelectrics as high-performance, eco-friendly alternatives to currently used ceramics.”

The research team at UL have previously utilised predictive computer models that allow them to identify how much electricity a biological material will generate when you squeeze it.

This makes the material suitable for power sensors in consumer electronics and medical devices.

The development has been published in the journal Physical Review Letters and will allow the researchers to shape the crystals they make using silicon moulds into discs or any custom shape required.

For example, a medical device element versus a phone microphone or car sensor shape can be moulded.

Tapping these discs and plates generates a useful voltage that, if amplified, could be used to charge electronic devices.

The research project, entitled Pb-FREE: Piezoelectric Biomolecules for Lead-Free, Reliable, Eco-Friendly Electronics, is being funded by a European Research Council (ERC) starting grant, awarded to associate professor Sarah Guerin.

The UL lecturer and researcher, Ms Guerin, who was named Research Ireland (SFI) Early Career Researcher of the Year in 2023, said she was optimistic about what this latest development could mean for solid-state chemistry.

“We hope it will be a game-changer for the whole field, because there are many scientists trying to grow biological crystals that are still behaving in a chaotic way,” she said.

“I am excited to see if this takes off as a methodology for other people working in sustainable piezoelectrics.

“There are EU regulations around the use of lead, but piezoelectrics are one of the last remaining mainstream technologies allowed to contain this substance because there is no high-performance alternative,” Ms Guerin concluded.

There are about 4,000 tons of lead-based electronic waste generated from these sensors every year and this research has the potential to remove this waste from the manufacturing process.