Domain Diversity and Polarization Switching in Amino Acid β-Glycine

Abstract

Piezoelectric materials based on lead zirconate titanate are widely used in sensors and actuators. However, their application is limited because of high processing temperature, brittleness, lack of conformal deposition and, more importantly, intrinsic incompatibility with biological environments. Recent studies on bioorganic piezoelectrics have demonstrated their potential in these applications, essentially due to using the same building blocks as those used by nature. In this work, we used piezoresponse force microscopy (PFM) to study the domain structures and polarization reversal in the smallest amino acid glycine, which recently attracted a lot of attention due to its strong shear piezoelectric activity. In this uniaxial ferroelectric, a diverse domain structure that includes both 180° and charged domain walls was observed, as well as domain wall kinks related to peculiar growth and crystallographic structure of this material. Local polarization switching was studied by applying a bias voltage to the PFM tip, and the possibility to control the resulting domain structure was demonstrated. This study has shown that the as-grown domain structure and changes in the electric field in glycine are qualitatively similar to those found in the uniaxial inorganic ferroelectrics.

Biomolecular Piezoelectric Materials: From Amino Acids to Living Tissues

“…Therefore, various biomaterials exhibit piezoelectricity, but generally do not show ferroelectricity. Recently, β and γ‐glycine crystals have also been found to exhibit ferroelectricity and it is therefore possible to control the polarization direction through an external electric field 73,74. In 2012, Heredia et al reported for the first time, that piezoelectric γ‐glycine exhibits robust and continuous nanoscale ferroelectricity, and that in principle, ferroelectric behavior can be sustained at a single molecule level (Figure 4b).…”

Glycine: The Gift that Keeps on Giving

“…[67,68] The domain structure is inherent for the β-polymorph also in the original as-grown crystals prior to any transformations and accounts for its remarkable physical properties, in particular, ferroelectric and piezoelectric properties. [85][86][87][88][89] Additional subtle effects were observed on cooling. As was evidenced by calorimetry, the β-polymorph undergoes a reversible second-order phase transition at 252 K. [69] The phase transition was recently shown to correspond to the transition from the paraelectric to the ferroelectric state.…”

“…[258] Glycine remains in the focus of these studies, even though the molecule is small, has no side residue and is achiral. Being piezo-and ferro-electric, [88][89][90]241,242,259] the β-and γ-polymorphs reversibly change their polarization under an electric field. The polarization switching is used to record/retrieve information in the form of ferroelectric domains.…”

The effect of CoFe2O4, CuFe2O4 and Cu/CoFe2O4 nanoparticles on the optical properties and piezoelectric response of the PVDF polymer

“…In the case of piezoelectric samples, the samples undergo a periodic deformation, taking along the tip. Such deformation can take place in any directions, therefore leading to deflection, buckling, or torsion of the cantilever [29]. Deflection is the consequence of an out of plane deformation (a change in the z-axis), buckling responds to an in-plane deformation (a diameter change in the y-axis) as well as torsion is related to another in-plane deformation (a length change in the x-axis).…”