Cellulose‐Based Flexible Functional Materials for Emerging Intelligent Electronics

Abstract

There is currently enormous and growing demand for flexible electronics for personalized mobile equipment, human–machine interface units, wearable medical‐healthcare systems, and bionic intelligent robots. Cellulose is a well‐known natural biopolymer that has multiple advantages including low cost, renewability, easy processability, and biodegradability, as well as appealing mechanical performance, dielectricity, piezoelectricity, and convertibility. Because of its multiple merits, cellulose is frequently used as a substrate, binder, dielectric layer, gel electrolyte, and derived carbon material for flexible electronic devices. Leveraging the advantages of cellulose to design advanced functional materials will have a significant impact on portable intelligent electronics. Herein, the unique molecular structure and nanostructures (nanocrystals, nanofibers, nanosheets, etc.) of cellulose are briefly introduced, the structure–property–application relationships of cellulosic materials summarized, and the processing technologies for fabricating cellulose‐based flexible electronics considered. The focus then turns to the recent advances of cellulose‐based functional materials toward emerging intelligent electronic devices including flexible sensors, optoelectronic devices, field‐effect transistors, nanogenerators, electrochemical energy storage devices, biomimetic electronic skins, and biological detection devices. Finally, an outlook of the potential challenges and future prospects for developing cellulose‐based wearable devices and bioelectronic systems is presented.

Sensors Made of Natural Renewable Materials: Efficiency, Recyclability or Biodegradability—The Green Electronics

“…The authors proposed to use such a device and substrate for point-of-care sensors. For more details, the reader can refer to the recent review from Zhao et al [ 58 ], who focused on the molecular structure and nanostructures (nanocrystals, nanofibers, nanosheets), and the processing technologies for fabricating cellulose-based flexible electronics. Miyashiro et al also reviewed cellulose-based materials, more particularly mixed materials of cellulose and carbon nanotubes [ 59 ], for electronic applications.…”

“…Still using natural materials, Gaspar et al published, in 2014, a cotton-based cellulose dielectric [ 58 ] used as both a substrate and gate dielectric in an oxide amorphous semiconductor FET. With an electron mobility above 7 cm 2 V −1 ·s −1 and an on/off ratio above 10 5 , the device presented an excellent operational stability after two weeks in air, without any type of encapsulation.…”

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“…CNP has been highlighted as an alternative to traditional plastic. It has broad application prospects not only for packaging but also in the fields of flexible electronics, biomedical devices, and water treatment (Zhao et al 2020). In addition, nanocellulose can be used as thin coatings for paper products to increase their barrier performance in packaging applications (Hubbe et al 2017).…”

3D‐Printed Wood‐Fiber Reinforced Architected Cellular Composites

“…[ 12 ] As one of the most common organic polymer, [ 13 ] cellulose is used for green biocomposite manufacturing and also is mechanically robust, [ 14 ] renewable, inexpensive, and biodegradable. Therefore, cellulose‐based natural composites have found a wide range of applications in thermal management, [ 15 ] electronics, [ 16 ] and construction and packaging. [ 17 ] Moreover, some cellulose derivatives, such as water‐soluble methyl cellulose and carboxymethyl cellulose, are being used in construction materials, pharmaceuticals, and cosmetics.…”