page_title: Nanogenerator
section_title: General theory for the polarization Ps
hierarchical_section_title: Nanogenerator / Theory of nanogenerators from Maxwell's equations / General theory for the polarization Ps
caption_attribution_description: English: Fig. 1. Schematic representation of a nanogenerator that is hooked up with an external load, and the corresponding coordination system for mathematical description.
context_page_description: A Nanogenerator is a type of technology that converts mechanical/thermal energy as produced by small-scale physical change into electricity. A Nanogenerator has three typical approaches: piezoelectric, triboelectric, and pyroelectric nanogenerators. Both the piezoelectric and triboelectric nanogenerators can convert mechanical energy into electricity. However, pyroelectric nanogenerators can be used to harvest thermal energy from a time-dependent temperature fluctuation.
  Nanogenerators are referred as a field that uses displacement current as the driving force for effectively converting mechanical energy into electric power/signal, disregarding if nanomaterials are used or not.
context_section_description: The polarization Pₛ created by the electrostatic surface charges can be expressed by the following equation, when defining the charge density function σₛ(r,t) on the media surface by a shape function of f(r,t)=0.
                               (4)
  where the delta function δ(f(r,t)) is introduced to confine the media shape. Through solving the scalar electric potential  from the surface charges
                     (5)
  the Pₛ can be obtained by
                                                                 (6)
  This is the general expression of the surface polarization density Pₛ in Eq. (3.1) and (3.4).
caption: Fig. 1. Schematic representation of a nanogenerator that is hooked up with an external load, and the corresponding coordination system for mathematical description.
exif: {}