Piezoelectricity in protein amino acids

The piezoelectric activity of protein amino acids and their compounds has been measured using the pulse method at a frequency of 10 MHz. It has been established that, at room temperature, the piezoelectric effect is not observed in α-glycine (achiral amino acid) and protein amino acids of the L modification, namely, methionine, phenylalanine, and tryptophan. An assumption has been made that this phenomenon is associated with the enhanced damping of elastic vibrations excited in samples due to the piezoelectric effect.