Robust and conductive hydrogel based on mussel adhesive chemistry for remote monitoring of body signals

Abstract

There is a high demand for hydrogels with multifunctional performance (a combination of adhesive, mechanical, and electrical properties) in biological, tissue engineering, robotics, and smart device applications. However, a majority of existing hydrogels are relatively rigid and brittle, with limited stretchability; this hinders their application in the emerging field of flexible devices. In this study, cheap and abundant potato residues were used with polyacrylamide (PAM) to fabricate a multifunctional hydrogel, and chitosan was used for the design of a three-dimentional (3D) network-structured hydrogel. The as-prepared hydrogels exhibited excellent stretchability, with an extension exceeding 900% and a recovery degree of over 99%. Due to the combination of physical and chemical cross-linking properties and the introduction of dopamine, the designed hydrogel exhibits a remarkable self-healing ability (80% mechanical recovery in 2 h), high tensile strength (0.75 MPa), and ultra-stretchability (900%). The resultant products offer superior properties compared to those of previously reported tough and self-healing hydrogels for wound adhesion. Chitosan and potato residues were used as scaffold materials for the hydrogels with excellent mechanical properties. In addition, in vitro experiments show that these hydrogels feature excellent antibacterial properties, effectively hindering the reproduction of bacteria. Moreover, the ternary hydrogel can act as a strain sensor with high sensitivity and a gauge factor of 1.6. The proposed strategy is expected to serve as a reference for the development of green and recyclable conductive polymers to fabricate hydrogels. The proposed hydrogel can also act as a suitable strain sensor for bio-friendly devices such as smart wearable electronic devices and/or for health monitoring.

Electrothermal Dry Adhesives with High Adhesion Under Low Temperatures Based on Tunable Stiffness

“…Unlike bioinspired dry adhesives relying on van der Waals forces, hydrogel adhesives achieve strong adhesion via the synergy of chemistry, mechanics, and topology. [78,79] In addition, anti-freezing hydrogel adhesives made via solute additions (salts, alcohols, and ionic liquids) exhibited excellent freezing resistances and low-temperature adhesion properties, [80] which are widely used in soft robotics, flexible sensors, and flexible batteries. However, solute diffusion in typi-cal aqueous environments affects the freezing resistance, which is detrimental to the long-term usage of anti-freezing hydrogel adhesives.…”

Organized mineralized cellulose nanostructures for biomedical applications

“…Natural structural mineralized materials created by living creatures are usually composed of stiff minerals and soft biopolymers that are organized into multi-dimensional hierarchical architectures. 1,2 For instance, teeth and bones are essentially comprised of hydroxyapatite (HAp) and collagen with a highly aligned one-dimensional (1D) structure to obtain outstanding load bearing capability. 3 Nacres utilize aragonite microplates and chitin/silk protein to build a two-dimensional (2D) brick-mortar architecture to overcome the trade-off between toughness and strength.…”

Balancing anti‐migration and anti‐aging behavior of binary antioxidants for high‐performance 1,2‐polybutadiene rubber

“…The PDA nano-coating could further react with amino and thiol functional groups through the classical Michael addition reaction. 24 Due to its simplicity, universality, and effectiveness, the mussel-inspired chemistry has emerged as one of the most widely used methods for the modification of inorganic fillers, which has been extensively explored for different applications recently, such as drug delivery, 25 proton exchange membranes, 26 3D printed bioreactors, 27 hydrogel, 28,29 and antibacterial materials. 30 At the same time, according to the molecular formula of polydopamine, its molecular structure is similar to aniline antioxidant.…”