Preparation of tough and ionic conductive PVA/carboxymethyl chitosan bio-based organohydrogels with long-term stability for strain sensor

Fan

ACS Appl. Mater. Interfaces

et al. 2023

100

Conductive hydrogels are ideal for flexible sensors, but it is still a challenge to produce such hydrogels with combined toughness, selfadhesion, self-healing, anti-freezing, moisturizing, and biocompatibility properties. Herein, inspired by natural skin, a highly stretchable, strainsensitive, and multi-environmental stable collagen-based conductive organohydrogel was constructed by using collagen (Col), acrylic acid, dialdehyde carboxymethyl cellulose, 1,3-propylene glycol, and AlCl 3 . The resulting organohydrogel exhibited excellent tensile (strain >800%), repeatable adhesion (>10 times), self-healing [self-healing efficiency (SHE) ≈ 100%], anti-freezing (−60 °C), moisturizing (>20 d), and biocompatible properties. This organohydrogel also possessed good electrical conductivity (σ = 3.4 S/m) and strain-sensitive properties [GF (gauge factor) = 13.65 with the maximal strain of 400%]. Notably, the organohydrogel had a considerable low-temperature self-healing performance (SHE = 88% at −24 °C) and rapid underwater selfhealing property (SHE = 92%, self-healing time <20 min). This type of strain sensor could not only accurately and continuously monitor the large-scale motions of the human body but also provide an accurate response to the human tiny motions. This work not only proposes a development strategy for a multifunctional conductive organohydrogel with multiple environmental stability but also provides potential research value for the construction of biomimetic electronic skin.

Section: Adhesion Property Of the Cdpap Organohydrogel Results Of Int...mentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Collagen-Based Organohydrogel Strain Sensor with Self-Healing and Adhesive Properties for Detecting Human Motion

Fan

ACS Appl. Mater. Interfaces

et al. 2023

100

Adv Healthcare Materials

“…[ 4 ] Flexible hydrogel strain sensors based on PVA have gained significant interest in recent years, with a heavy focus on conductivity, stretchability, and mechanical toughness. Previous strategies for achieving conductivity have involved doping with salts such as sodium chloride, [ 5‐10 ] zinc sulfate, [ 11 ] sodium borate, [ 12‐14 ] iron(III) chloride, [ 15,16 ] calcium chloride, [ 17,18 ] or lithium chloride. [ 19 ] Higher gauge factors (GFs) and wider dynamic range can be achieved by using conductive polymers like poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) [ 20 ] or conductive fillers like graphene, [ 9,12 ] silver nanowires (AgNWs), [ 12,21 ] or carbon nanotubes (CNTs).…”

Section: Introductionmentioning

confidence: 99%

A Transparent Poly(vinyl alcohol) Ion‐Conducting Organohydrogel for Skin‐Based Strain‐Sensing Applications

Paik

Jang

Nam

et al. 2023

The increasing demand for cost‐efficient and user‐friendly wearable electronic devices has led to the development of stretchable electronics that are both cost‐effective and capable of maintaining sustained adhesion and electrical performance under duress. This study reports on a novel physically crosslinked poly(vinyl alcohol) (PVA)‐based hydrogel that serves as a transparent, strain‐sensing skin adhesive for motion monitoring. By incorporating Zn2+ into the ice‐templated PVA gel, a densified amorphous structure is observed through optical and scanning electron microscopy, and it is found that the material can stretch up to 800% strain according to tensile tests. Fabrication in a binary glycerol:water solvent results in electrical resistance in the kΩ range, a gauge factor of 0.84, and ionic conductivity on the scale of 10−4 S cm−1, making it a potentially low‐cost candidate for a stretchable electronic material. This study characterizes the relationship between improved electrical performance and polymer–polymer interactions through spectroscopic techniques, which play a role in the transport of ionic species through the material.

Journal of Polymer Science

Facile preparation and performance of flexible sensors based on polyacrylamide/carboxymethylchitosan/tannin acid hydrogels

Liu,

Huang,

et al. 2024

Hydrogel flexible sensors are gaining significant interest due to their distinct biocompatibility, flexibility, and unique features of being adjustable and injectable, but there are still problems of poor self‐healing performance and low conductivity in the current stage of research. In this work, a prefabricated blending method was used to construct a dual‐network system using polyacrylamide (PAM), carboxymethyl chitosan (CMCS), and tannin acid (TA), and ferric ions (Fe3+) were introduced to apply ionically conductive organic hydrogels to flexible sensors. The PAM/CMCS‐Fe3+/TA hydrogels have good fatigue resistance and self‐healing properties, and their conductivity is as high as 6.42 S/m. This hydrogel‐based sensor for strain sensing purpose offers a lot of promise for flexible sensor applications since it can provide steady, dependable, and repeatable electrical impulses.