These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
PiezoPeptides.pdf (879.94 kB)
Origins of Negative and Positive Electromechanical Response of Oligopeptide Piezoelectrics
Preprints are manuscripts made publicly available before they have been submitted for formal peer review and publication. They might contain new research findings or data. Preprints can be a draft or final version of an author's research but must not have been accepted for publication at the time of submission.
In response to an applied electric field, materials and even individual molecules can exhibit electromechanical response. Previous work has demonstrated the piezoelectric distortion of polar organic crystals, biomaterials, and even single molecular monolayers, increasing length in response to the change in potential energy of interaction between the polarization or dipole moment and the applied electric field. In this work, we demonstrate through density functional calculations that helical oligopeptides, depending on sequence can exhibit both positive and surprisingly also negative piezoresponse. While the overall molecular dipole moment may favor positive piezoresponse, individual hydrogen bonding interactions along the backbone have the opposite direction, enabling tailored sequences to yield either net expansion or contraction in response to an electric field. While negative piezoresponse has largely been considered in polyvinylidene difluoride (PVDF) and related systems, understanding the atomic and molecular basis for both electromechanical effects will yield interesting new applications.