Shed a tear for science? University researchers in Ireland harvest electricity from tears

University of Limerick’s Bernal Institute in Ireland was recently home to a startling discovery when researchers discovered that lysozyme crystals found in tears yield an electric current when pressurized, a quality termed piezoelectricity. Findings were published in an October 2nd report in the journal, Applied Physics Letters.

According to Aimee Stapleton, Bernal Institute physicist and lead author of the report, piezoelectricity is quite common, though its existence in lysozyme had not previously been explored. “The extent of the piezoelectricity in lysozyme crystals is significant,” she said. “It is of the same order of magnitude found in quartz. However, because it is a biological material, it is non-toxic, so it could have many innovative applications such as electroactive anti-microbial coatings for medical implants.”

 

Bernal Institute researchers John Sweeney, Aimee Stapleton, and Vincent Casey. Credit: Sean Curtin, True Media

 

During the experiment, researchers crystallized lysozyme using high levels of heat, pressurized the crystals and measured the electric charge emitted by the substance. Anticipating a measurement of approximately 1 picocoulomb per newton, researchers were startled to discover its actual piezoelectric effect measured anywhere from 2 to 6.5 picocoulombs per newton. “We were quite excited by that,” said Stapleton.

 

Lysozyme, found in tears, eggs and milk is a potential source of energy for batteries say researchers.

 

Lysozyme found in milk, eggs

Lysozyme, found in tears and chicken eggs, can be a source of energy for batteries researchers find.

In addition to tears, lysozyme can be found in saliva, mucus, milk, and chicken eggs. The abundance of lysozyme makes it an inexpensive and renewable material with which to work. It was also chosen for the experiment due to its crystal structure, which is a key factor in piezoelectricity. Though more complex materials are used when studying piezoelectric capabilities, the researchers began experimenting with simple proteins in the hopes of gaining a deeper understanding of the process and its implications. Stapleton stated that she and her team do not fully understand how piezoelectricity works, so they chose to “start with more fundamental building blocks.”

Further tests are being done to determine whether the protein has a converse piezoelectric effect, which would mean that the application of electricity would create a deformation of the crystal material. The existence of such an effect in lysozyme could have various potential uses as well.

Xudong Wang, Professor of Materials Science and Engineering at the University of Wisconsin, stated, “I think the performance is still the most important aspect of new material discovery. The paper mentioned the piezoelectric coefficient is about the same as quartz. This is kind of low for energy harvesting applications. It will be very interesting to know the theoretical limit of this new material.”

Did you miss this?

Other Popular Stories

  • Little certainty about toxicity of BPA in food cans despite new report
  • World will invest $7.8 trillion in solar, wind over next 25 years: Bloomberg
  • More positive outlook for economy as March sales rebound
  • Steel producers, clean tech, IT see reason to support the federal budget
  • Forestry industry pledges 13 per cent CO2 reduction to fight climate change
  • No-cost energy-reduction plan offered to Ontario businesses
  • Ford GT supercar in production at Markham's Multimatic plant
  • Unusual hydrogen car could soon be built in UK
  • Chrysler expanding Windsor assembly plant for "future vehicle"
  • Promise of more investment in auto industry but no specifics
  • NASA says human Mars landing is feasible by 2030s
  • Deep Roads — researchers propose taking road expansion underground to reduce congestion and pollution
  • Bombardier to hit business jet targets: aiming for US$8.5 billion annually by 2020
  • Canada's prosperity at risk from disruption, lack of skilled workforce: reports
  • Will quotas, targets and better technology get more drivers into EVs?
  • Researchers claim breakthrough in artificial photosynthesis
  • Building permits up in June, non-residential construction leading
  • Manufacturing continues to grow but exports decline, increasing Canada's trade deficit in February
  • Little support in auto industry for Canada/Korea free trade deal
  • New MRO operation rising in former Aveos plant
Scroll to Top