Soft Stretchable Conductive Carboxymethylcellulose Hydrogels for Wearable Sensors

Abstract

Hydrogels that have a capability to provide mechanical modulus matching between time-dynamic curvilinear tissues and bioelectronic devices have been considered tissue-interfacing ionic materials for stably sensing physiological signals and delivering feedback actuation in skin-inspired healthcare systems. These functionalities are totally different from those of elastomers with low ionic conductivity and higher stiffness. Despite such remarkable progress, their low conductivity remains limited in transporting electrical charges to internal or external terminals without undesired information loss, potentially leading to an unstable biotic–abiotic interfaces in the wearable electronics. Here, we report a soft stretchable conductive hydrogel composite consisting of alginate, carboxymethyl cellulose, polyacrylamide, and silver flakes. This composite was fabricated via sol–gel transition. In particular, the phase stability and low dynamic modulus rates of the conductive hydrogel were confirmed through an oscillatory rheological characterization. In addition, our conductive hydrogel showed maximal tensile strain (≈400%), a low deformations of cyclic loading (over 100 times), low resistance (≈8.4 Ω), and a high gauge factor (≈241). These stable electrical and mechanical properties allowed our composite hydrogel to fully support the operation of a light-emitting diode demonstration under mechanical deformation. Based on such durable performance, we successfully measured the electromyogram signals without electrical malfunction even in various motions.

Advances in Cellulose-Based Hydrogels for Biomedical Engineering: A Review Summary

“…Thus, this work offers new opportunities for future self-powered transient electronic devices or traditional self-powered implantable medical devices, such as implantable cardioverter defibrillators, implantable diagnostic sensors and the rapidly evolving implantable monitoring of diabetes. In addition, a soft stretchable conductive hydrogel composite consisting of alginate, carboxymethyl cellulose, polyacrylamide, and silver flakes was reported [ 133 ].…”

Synthesis and Applications of Carboxymethyl Cellulose Hydrogels

“…In addition to their application in medical fields as anti-tumor and bacteriostatic agents, hydrogels have applications in agriculture [ 56 , 57 , 58 ], wound healing [ 59 ] and other fields [ 60 , 61 , 62 , 63 ].…”

Electrospun Core (HPMC–Acetaminophen)–Shell (PVP–Sucralose) Nanohybrids for Rapid Drug Delivery

“…Cellulose, as one of the most abundant natural resources, has been exploited in the field of drug delivery for many years [ 1 , 2 , 3 , 4 , 5 , 6 ]. Particularly, it has a wide variety of derivatives, which have different chemical and physical properties for different drug controlled-release performances [ 7 , 8 , 9 , 10 , 11 ]. For example, acetate cellulose, an insoluble derivative, is frequently utilized to provide a sustained drug release profile [ 12 , 13 , 14 ].…”