Polymer-Dispersed Liquid Crystals Actuated by a Rotary Triboelectric Nanogenerator

Abstract

In this work, polymer-dispersed liquid crystals (PDLCs) under an applied electric field are actuated by a rotary triboelectric nanogenerator (r-TENG). Conventional PDLCs generally rely on high DC voltages for on-off switching, but they can also be effectively switched on and off using an moderate high AC voltage at a frequency of several kHz with a smaller voltage. Here, we use a simple r-TENG to study the optical states of PDLC cells at different low frequencies (2–100 Hz) and simultaneous monitoring of the open-circuit voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{V}_{\text{oc}}$ </tex-math></inline-formula> ) and short-circuit current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{I}_{\text{sc}}$ </tex-math></inline-formula> ) to describe the optical performance of PDLC cells with different thicknesses. The results show that the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{I}_{\text{sc}}$ </tex-math></inline-formula> , provided by a r-TENG with a low <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{V}_{\text{oc}}$ </tex-math></inline-formula> (1-2V), inside a PDLC cell is the key factor that determines its performance. Through the application of the r-TENG, we successfully demonstrate the on-off switching of nine PDLC cells connected in series with an area of 15 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times15$ </tex-math></inline-formula> mm, and the power consumption is equal to that of a single PDLC cell. This research expands the potential applications of TENGs in photonics and also provides a way to improve the optical properties of PDLCs by connecting TENGs to achieve optimal performance for PDLC-related optoelectronic devices.