Stretchable and Transparent Paper Based on PDMS–CNC Composite for Direct Printing

Abstract

Stretchable devices significantly expand the scope of applications such as flexible displays and wearable devices/sensors. To enable stretchable wearable electronics, methods for connecting unit devices and developing circuits are required. Previously, research was performed to manufacture circuits with 3D structures or patterns that remain intact when the flexible and stretchable substrates are deformed. A method for drawing a circuit directly on a substrate with a conductive ink pen is proposed, although it is limited by the surface properties of the substrate. Most existing transparent papers are not sufficiently stretchable for flexible and wearable electronics applications. Therefore, a polydimethylsiloxane–cellulose nanocrystals (PDMS–CNC) composite paper is developed that is both highly flexible and stretchable, while maintaining a high transmittance. The versatility of the composite paper is demonstrated as a suitable substrate for flexible devices by patterning with a conductive ink pen. The PDMS–CNC composite paper has an excellent transmittance of ≈70%, and can withstand over 800% tensile strain. The patterned circuits have only minor increase in resistance after a 50% deformation and recovery. The composite paper is a suitable technology for fabricating electrical components and devices for the Internet of Things and wearable and flexible electronics applications.

Advances in Printing and Electronics: From Engagement to Commitment

“…The proposed stretchable and transparent device proved to be an appropriate substrate for resistor, inductor, and capacitor assemblies, preserving the transmittance of ≈70%. [ 388 ] In the particular case of inductors, fully 3D printed broadband conical‐shape structures (without resonant broadband features) were prepared by using engineered magnetic inks composed of 70 vol% of NEA121 polymer, and 30 vol% of iron‐cobalt. Three types of inductors were evaluated: i) an aerosol‐jet printed polymer core to be used as reference; ii) an iron‐cobalt core, and; iii) an iron‐based powder, the last 2 fabricated by paste‐extrusion.…”

Nanopaper Electronics

“…Ryu et al reported a polydimethylsiloxane-cellulose nanocrystals composite paper that is highly flexible and stretchable while maintaining a high transmittance. [82] Their composite paper has a transmittance of ≈70% and can withstand over 800% tensile strain. The patterned circuits have only a minor increase in resistance after a 50% deformation and recovery.…”

A Hybrid Titanium-Softmaterial, High-Strength, Transparent Cranial Window for Transcranial Injection and Neuroimaging

“…Titanium (Ti) mesh is a typical metallic cranioplasty material for its excellent biocompatibility, high strength and perfect structural stability [ 64 , 65 , 66 , 67 , 68 , 69 , 70 ]. Meanwhile, PDMS is a soft material with high transmittance, biocompatibility, and penetrability [ 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 ]. In this paper, we demonstrate a multifunctional cranial window device made from Ti and PDMS by a novel process.…”