Enhancing the Optical Response Speed of Thermochromic Paper Displays by Heat Exchange Manipulation of Invisible Heaters

Abstract

Developing invisible heaters is critical to thermochromic paper displays for convenient and low power use. Maintaining high transmittance as well as uniform and widely adjustable resistance remains a challenge for quick and efficient heat exchange in paper displays. Here, through optimizing the spraying process parameters and the dynamic spraying path design on paper, highly uniform and continuously varied film sheet resistance is achieved. Through silver nanowire percolation control, the heat-transfer coefficient is manipulated from 20 to 40 W m–2 K–1. By directly printing high-resolution thermochromic patterns on the invisible heater side, fast and efficient heat transfer is achieved under a voltage lower than 9 V and benefits paper displays with a second-level optical response time and a power consumption below 30 mW cm–2. Large chromatic aberration and discoloration speed are demonstrated from quantitative analysis of both static and dynamic reflection spectra. Guidance for designing thermochromic paper displays with fast response is provided.

Fabrication strategies for metallic nanowire flexible transparent electrodes with high uniformity

“…In contrast, the spray-coated FTE displayed parallel equipotential lines corresponding to a homogenous distribution of Ag NWs. Tao et al 93 fabricated highly uniform Ag NW conductors on paper substrates through an optimized spraying process with the proper spraying path and parameters. The NUF was reduced to below 10% and even 5% under certain conditions.…”

Facile filter cloth brush-coating of large-area uniform silver nanowire conductive films for paper-based heater

“…In addition, printing large-area uniform AgNW films on paper surfaces is also challenging due to the porous nature of paper. Recently, uniform paper-based AgNW heater through optimizing the spaying process has been reported and was used in thermochromic paper displays [23].…”