What powers our heart and lungs?

The process that serves as a way to power computer memory chips, display screens and sensors is seen in a protein found in human hearts, lungs and arteries, organs that repeatedly stretch and retract. Ferroelectric switching, a response to an electric field in which a molecule switches from having a positive to a negative charge, happens in the biological protein elastin, the study showed. This switching process in synthetic materials serves as a way to power computer memory chips, display screens and sensors. “When we looked at the smallest structural unit of the biological tis-sue and how it was organised into a larger protein fibre, we then were able to see similari-ties to the classic ferroelectric model found in solids,” said Jiangyu Li, professor at Uni-versity of Washing-ton in the US. The researchers used small samples of elastin taken from a pig’s aorta and poled the tis-sues using an elec-tric field at high temperatures. They then measured the current with the poling field removed and found that the current switched direction when the poling electric field was switched, a sign of ferroelectricity. They did the same thing at room temperature using a laser as the heat source, and the current also switched directions. Then, the researchers tested for this behaviour on the smallest-possible unit of elastin, called tropoelastin, and again observed the phenomenon. They concluded that this switching property is “intrinsic” to the mo-lecular make-up of elastin. The study appeared in the journal Proceedings of the National Acad-emy of Sciences.