Enzymes can turn tears into electricity

An enzyme found in tears is capable of converting mechanical energy into electrical energy.

Irish scientists have discovered an enzyme called lysozyme that turns tears into electricity, according to Live Science. In addition to tears, lysozyme also exists in saliva and mammalian milk, a study published today in the journal Applied Physics.

Lysozyme is an antibacterial agent that attacks the cell walls of bacteria and weakens them. When lysozyme is crystalline, it seems to have a feature called piezoelectricity , meaning that the enzyme can convert mechanical energy into electrical energy.

According to lead researcher Aimee Stapleton, a physics student at the University of Limerick, Ireland, piezoelectricity is used everywhere around us. For example, piezoelectric materials such as quartz crystals used in mobile phones and deep sea waves.

In fact, materials such as bone, wood, tendons and proteins (including collagen and keratin) are also piezoelectric, according to the study. "But the ability to generate electricity from this particular protein (lysozyme) has never been discovered ," Stapleton said.

To study the piezoelectricity of the lysozyme, scientists rubbed the crystalline form of the enzyme on the film. They then apply mechanical force to these films and record the amount of electricity produced.

The team found that lysozyme could produce as well no quartz. But lysozyme is a biological material that can be used in medicine. "Lysozyme is non-toxic, so there are new applications like electrochemical coatings for medical implants," Stapleton said.

The researchers said that in the future, lysozyme could be used to provide energy to biological devices operating in the human body. This enzyme can also be used to control drug release in the body.