Piezo-/ferroelectric phenomena in biomaterials: A brief review of recent progress and perspectives

There have been overwhelming observations of piezo-/ferroelectric phenomena in many biological tissues and macromolecules, boosting the development of bio-based smart devices and the applications using electromechanical coupling phenomena in biological systems. The electromechanical coupling is believed to be responsible for various biophysical behaviors and remarkable biomaterial properties. Despite the abundant phenomenal observations, the fundamental understanding of the piezo-/ferroelectric effect in biomaterials/systems and the rational design of biobased macroscopic materials with desired piezoelectric responses are still scarce. In this review, we firstly present remarkable historical events on the development of piezo-/ferroelectricity in biomaterials, followed by a brief overview of the fundamental physics of piezo-/ferroelectricity. The developments of biopiezo-/bioferroelectricity in protein-based biomaterials and their implications are highlighted subsequently. In experimental studies, to identify the intrinsic piezo-/ferroelectric properties from other effects or artifacts is usually elusive. This issue is also addressed and discussed in detail, especially using piezoelectric force microscopy (PFM) and spectroscopy techniques to investigate the local piezo-/ferroelectric phenomena in nanostructured materials are highlighted emphatically.