A team of Irish scientists have found that applying pressure to a protein found in egg whites and tears can generate electricity. Researchers at the Bernal Institute, University of Limerick (UL), Ireland, observed that crystals of lysozyme, a model protein abundant in the egg whites of birds as well as in the tears, saliva and milk of mammals, can generate electricity when in a hurry. . Their report is published today (October 2) in the journal, Letters of Applied Physics.
The ability to generate electricity by applying pressure, known as direct piezoelectricity, is a property of materials such as quartz that can convert mechanical energy into electrical energy and vice versa. These materials are used in a variety of applications ranging from resonators and vibrators in cell phones to deep ocean sonar to ultrasound imaging. Bones, tendons, and wood have long been known to possess piezoelectricity.
“Although piezoelectricity is used all around us, the ability to generate electricity from this particular protein has not been explored. The extent of piezoelectricity in lysozyme crystals is significant. same order of magnitude as that found in quartz. is a biological material, it is not toxic and therefore could have many innovative applications such as electroactive and antimicrobial coatings for medical implants ”, explained Aimee Stapleton, lead author and Irish Research Council EMBARK Postgraduate Fellow in the Department of Physics and Bernal Institute at UL.
Lysozyme crystals are easy to make from natural sources. “The high-precision structure of lysozyme crystals has been known since 1965,” said UL structural biologist and co-author Professor Tewfik Soulimane. “In fact, this is the second protein structure and the first enzymatic structure ever to be resolved,” he added, “but we are the first to use these crystals to show proof of piezoelectricity.”
According to the team leader, Professor Tofail Syed of the Department of Physics at UL, “Crystals are the gold standard for measuring piezoelectricity in non-biological materials. Our team has shown that the same approach can be adopted to understand this effect in biology. This is a new approach because scientists have so far tried to understand piezoelectricity in biology using complex hierarchical structures such as tissues, cells or polypeptides rather than studying fundamental building blocks. simpler “.
The discovery could have wide-ranging applications and could lead to further research in the area of energy harvesting and flexible electronics for biomedical devices. Future applications of the discovery could include controlling drug release in the body using lysozyme as a physiologically mediated pump that recovers energy from its surroundings. Being naturally biocompatible and piezoelectric, lysozyme may present an alternative to conventional piezoelectric energy scavengers, many of which contain toxic elements such as lead.
Professor Luuk van der Wielen, Director of the Bernal Institute and Bernal Professor of Biosystems Engineering and Design expressed his joy at this breakthrough by UL scientists. “The Bernal Institute has the ambition to make an impact on the world on the basis of cutting-edge science in an increasingly international context. The impact of this discovery in the field of biological piezoelectricity will be enormous and Bernal scientists are leading advances in this area head on, “he said.
The full article, The Direct Piezoelectric Effect in the Globular Protein Lysozyme, by Aimee Stapleton, Mohamed R Noor, John Sweeney, Vincent Casey, Andrei Kholkin, Christophe Silien, Abbasi A. Gandhi, Tewfik Soulimane and Syed AM Tofail, is published in Applied Letters of Physics (October 2, 2017). The article is available on https://doi.org/10.1063/1.4997446.
For more information, photographs or to arrange an interview, please contact:
University of Limerick
Notes to editor:
Aimee Stapleton received funding from the Irish Research Council EMBARK Postgraduate Scholarship. Part of this study was also facilitated by a grant from the Higher Education Authority under the Third Level Institutional Research Program (PRTLI 5) at the University of Limerick.
About Aimée Stapleton:
Aimee Stapleton, from Nenagh, County Tipperary, Ireland, has just completed her doctorate in the Department of Physics and Energy at the University of Limerick. She used a number of methods, including piezo-response force microscopy, to study piezoelectricity (electromechanical coupling) in proteins. Before starting her doctoral studies, she obtained an Honors BA in Applied Physics. During her studies, she did an internship at 2M Engineering in the Netherlands, where she researched laser technologies. In addition to her research activities, Aimee has a keen interest in science communication as well as teaching and learning. In 2015, she won the Rosse Medal award from the Institute of Physics for the best postdoctoral research communication.
About the Bernal Institute:
The Bernal Institute at the University of Limerick is a research institute comprising 20,000 m2 of high-quality multipurpose research space in the new scientific and technical area of UL. The Bernal Institute is named after John Desmond Bernal, one of the most influential scientists of the 20th century, born in Nenagh, County Tipperary.
About the University of Limerick:
University of Limerick, Ireland, with more than 13,000 students and 1,300 employees, is an energetic and enterprising institution with a proud record of innovation and excellence in education, research and scholarship. The dynamic, entrepreneurial and pioneering values that drive UL’s mission and strategy ensure that it capitalizes on local, national and international engagement and connectivity.
About Applied Physics Letters:
Applied Physics Letters (APL) presents concise and up-to-date reports on important new discoveries in applied physics. With an emphasis on the rapid dissemination of key data and new physical knowledge, the APL offers the rapid publication of new experimental and theoretical papers describing the applications of physical phenomena to all branches of science, engineering and of modern technology.
Letters of Applied Physics
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of any press releases posted on EurekAlert! by contributing institutions or for the use of any information via the EurekAlert system.