Recent Advances in Chitosan-Based Hydrogels for Flexible Wearable Sensors

Abstract

Flexible wearable sensors show great potential for applications in wearable devices, remote health monitoring, artificial intelligence, soft robotics, and artificial skin due to their stretchability, bendability, thinness and portability, and excellent electrical properties. Hydrogels have tunable mechanical properties, excellent biocompatibility, and flexibility, making them attractive candidates for wearable flexible sensors. Among them, tremendous efforts have focused on the advancement of chitosan-based hydrogels (CS-Gels) to realize multifunctional wearable sensing by modifying hydrogel networks with additives/nanofillers/functional groups. Recently, remarkable progress has been made in flexible wearable sensors. Herein, this review summarizes recent advances in CS-Gels wearable sensors for applications such as human motion monitoring, health monitoring, human-machine interface and soft robotics. Representative synthesis methods and strategies for CS-Gels are briefly described, the problems and deficiencies of CS-Gels for wearable sensors are discussed. Finally, the possible opportunities and challenges for the future development of CS-Gels flexible wearable devices are proposed.

Biofluid‐Activated Biofuel Cells, Batteries, and Supercapacitors: A Comprehensive Review

“…Deleterious effects of variations in flow rate and concentration of fuel and evaporative losses of biofluid could be addressed by interfacing the devices with advanced hydrogels that retain the biofluid by acting as a reservoir and enabling continuous operation. [201][202][203][204][205] Moreover, integrated systems that combine BFCs with B-ESSs could further assist in offering a continuous supply of stable power even under a variable supply of biofluids. Fluctuating pH of unbuffered biofluids such as sweat, tears, saliva, and urine is another major challenge that researchers must take into account while developing biofluid-activated energy devices since enzymatic activity as well as battery chemistry are dependent on pH.…”

Multiple-Language-Responsive Conductive Hydrogel Composites for Flexible Strain and Epidermis Sensors

“…Skin-like, stretchable materials are the sub-field of flexible electronic devices, which can convert various external stimuli like temperature, mechanics, and humidity into measurable electrical signals. These flexible devices have potential applications in the field of health monitoring, , humanoid robotics, and human–machine interfaces . Recently, a large number of human-skin-like strain sensors have been designed by introducing various kind of conductive materials (metals, conductive polymers, and carbon nanoscale materials) into extensible polymer structures .…”

Evaluation of the Dye Extraction Using Designed Hydrogels for Further Applications towards Water Treatment

“…The creation of new hydrogel forms and the modification of available solutions are the result of the need for new functional materials. In the world of biopolymer hydrogel systems, active research concerns chitosan-based composite hydrogels for biomedical applications [ 6 , 7 , 8 , 9 , 10 , 11 ] such as novel heat-sensitive chitosan hydrogels in combination with polyols or polyoses [ 12 ]; gold and silver–gold chitosan hydrogels and hydrogel-modified textiles [ 13 , 14 ]; supramolecular chitosan-based hydrogels for 3D bioprinting [ 15 , 16 ]; hydrogels as space-confining media for the synthesis of nanostructural materials [ 17 ]; superporous chitosan hydrogels as pH-sensitive materials [ 18 ]; and chitosan-based hydrogels for multifunctional, wearable sensory properties [ 19 ]. Final chitosan-based hydrogels have gained considerable attention in terms of water purification due to their great adsorption capacity toward pharmaceutics, heavy and rare earth hazardous metals [ 20 , 21 ], and dyes [ 22 , 23 , 24 ].…”