A Contact‐Sliding‐Triboelectrification‐Driven Dynamic Optical Transmittance Modulator for Self‐Powered Information Covering and Selective Visualization

Abstract

Triboelectrification‐enabled self‐powered flexible electronic/optical systems have aroused a new surge of interest in recent years. All‐in‐one integration of such a system, which could significantly improve its adaptability, operability, and portability, still remains a challenge due to the absence of suitable architectures and integration schemes. Herein, a previously reported self‐powered optical switch (OS) is thoroughly remolded and upgraded to a fully integrated contact‐sliding‐triboelectrification‐driven dynamic optical transmittance modulator (OTM). The OTM is constructed with a multilayered structure, comprising a transparent triboelectrification top layer, a SiO2‐spaced polymer dispersed liquid crystal (PDLC) intermediate layer, and a flexible transparent conductive substrate. The working mechanism is that an alternating electric field can be induced once contact‐sliding occurs upon the OTM, rendering the PDLC layer immediately switching its initial translucent state to an instantaneous transparent state. As such, a decent dimming range with the relative transmitted light intensity from 0.17 to 0.72 can be achieved at low mechanical thresholds of contact pressure (≈20 kPa) and sliding velocity (≈0.3 m s−1). Moreover, for practical applications, demonstrations of information covering and selective visualization are successfully implemented without any extra optical elements nor external power supplies, explicitly showing great potential for the OTM in various self‐powered optical interactive applications.

Progress inTENGtechnology—A journey from energy harvesting to nanoenergy and nanosystem

“…Besides polymer dispersed liquid crystal, self-powered elastomer-based tunable displays are also realized by TENG. 104,256 The voltage output from TENG induces rippling of the elastomer that varies its transparency. Recently, TENG has been successfully applied for nanophotonic modulation.…”

“…Due to the triboelectrically generated voltage induced alignment change in the liquid crystal, the transmittance of the liquid crystal changes from 85% to 5%, this is enough for privacy protection (Figure 9I‐II, III). Besides polymer dispersed liquid crystal, self‐powered elastomer‐based tunable displays are also realized by TENG 104,256 . The voltage output from TENG induces rippling of the elastomer that varies its transparency.…”

Flexible and Stretchable Fiber‐Shaped Triboelectric Nanogenerators for Biomechanical Monitoring and Human‐Interactive Sensing

“…[ 23–25 ] As a new energy harvesting method, TENGs have many advantages, such as light weight, low cost, versatile material selection, and simple structure design. [ 26–28 ] In addition, the coaxial structure has been widely applied for fiber‐shaped supercapacitors, [ 29–31 ] lithium batteries, [ 32 ] and solar cells. [ 33–34 ] And the coaxial structure shows a higher stability under various mechanical deformations, especially bending and stretching.…”

Spatially Patterned Polymer Dispersed Liquid Crystals for Image‐Integrated Smart Windows

“…Polymer dispersed liquid crystals (PDLCs) belong to a class of electro-optic materials that have found application in a wide range of technologies including optical switches, light shutters, holographic gratings and, most notably, as electrically switchable privacy windows. [1][2][3][4][5] In the latter case, it is well known that PDLCs can be employed as an electrically-switchable alternative to conventional blinds or curtains as they can that has been proposed for obtaining a patterned PDLC film involves the use of holographic photopolymerization where two laser beams generate an interference pattern within a homogeneous LC and prepolymer formulation resulting in the formation of separate polymer-rich and LC-rich domains. [23,24] Other methods reported for producing a patterned PDLC film include the use of high-power light-emitting diodes, photomasks, chemically patterned substrates, and using mechanical stamping processes.…”