fig3
Figure 3. Piezoelectric properties of organic molecules with higher-order structure. (A) Hydroxyproline-Phenylalanine-Phenylalanine (Hyp-Phe-Phe) single-crystals are attracted through intermolecular hydrogen bonds (HB) and aromatic zipper-like packing, and form a helical stacking structure. Reproduced with permission[39]. Copyright 2021, Springer Nature. (B) The β-sheet content and crystal orientation determine the piezoelectricity of silk fibroin. Reproduced with permission[40]. Copyright 2011, John Wiley and Sons. (C) Atomic models of a single collagen molecule and collagen microfibril with five D-periods (each D period of around 67 nm). Reproduced with permission[41]. Copyright 2016, American Chemical Society. (D) Schematic illustration of the interlocked structure of the gelatin film cross-linked by glutaraldehyde with microdome structure. Reproduced with permission[49]. Copyright 2021, John Wiley and Sons. (E) Schematic illustration of the vertically polarized M13 bacteriophage nanostructure filled in polydimethylsiloxane (PDMS) microfluidic channels. Reproduced with permission[54]. Copyright 2019, American Chemical Society. (F) Dipoles on the poly(L-lactic acid) (PLLA) molecular chain are oriented to the same direction after stretching. Reproduced with permission[1]. Copyright 2019, John Wiley and Sons. (G) Dipoles on the PLLA molecular chain are oriented to the same direction after applying stress. Reproduced with permission[67]. Copyright 2018, National Academy of Science. (H) Chemical structure of cellulose, chitosan and chitin. Reproduced with permission[38]. Copyright 2021, Elsevier. (I) Schematic illustration of covalent bonds (CB) and HB arrangements in 2D nanocellulose crystal. (J) Calculated piezoelectric responses for single HB (upper) and extended crystal (lower). (K and I) reproduced with permission[80]. Copyright 2016, Springer Nature. (K) Vertical displacement of cellulose nanocrystal thin films with different alignment corresponding to externally applied electric fields. Reproduced with permission[82]. Copyright 2012, American Chemical Society.
