Soft Electronic Materials with Combinatorial Properties Generated via Mussel-Inspired Chemistry and Halloysite Nanotube Reinforcement

Abstract

Soft and electrically active materials are currently being utilized for intelligent systems, including electronic skin, cybernetics, soft robotics, and wearable devices. However, fabricating materials that fulfill the complex requirements of such advanced applications remains a challenge. These attributes include electronic, adhesive, self-healing, flexible, moldable, printable, and strong mechanical properties. Inspired by the recent interest in transforming monofunctional materials into multifunctional ones through nanoreinforcement and mussel-inspired chemistry, we have designed a simple two-step methodology based on halloysite nanotube (HNT) and polydopamine (PDA) to address the grand challenges in the field. In brief, HNTs were coated with PDA and embedded within a poly(vinyl alcohol) (PVA)-based polymeric matrix in combination with ferric ions (Fe 3+ ). The final composite displayed a 3-fold increase in electrical conductivity, a 20-fold increase in mechanical stiffness, and a 7-fold increase in energy dissipation in comparison to their nonfunctional counterparts, which arose from a combination of nanotube alignment and mussel-inspired chemistry. Moreover, the developed composite could elongate up to 30000% of its original length, maintain its electrical properties after 600% strain, self-heal within seconds (both electrically and mechanically), and display strain-sensitivity. Finally, it was 3D-printable and thus amenable for engineering of customized wearable electronics.

Biomimetic Flexible Electronic Materials from Silk Fibroin-MXene Composites Developed via Mussel-Inspired Chemistry as Wearable Pressure Sensors

“…The tunneling current achieved by the MXene nanosheets in composite gum samples of this study resulted in a higher electrical conductivity (4 times increment) than those of initial SF-TA-based gums and CareGum , and other reported gum-based materials, namely, gellan gum/polyacrylamide (PAAm) and carboxymethyl guar gum (CMGG)/poly (acrylic acid) (PAA) equipped with only ionic conductivity. The stretchability, working strain, electrical conductivity, bodily motion sensing, and strain sensitivity ranges of fabricated gums are also in agreement with those observed in the ternary hybrid network hydrogels of TA-modified cellulose nanofibers/MXene nanosheet network/cross-linked polypropylene amine (PAAM) reported by Alshareef et al …”

“…However, despite the good pressure sensing performance of SF-MXene foam, the durability of foams under repeated compression and decompression cycles was limited. Recently, tissue-like, self-healable, and stretchable SF-graphene-based gums (“CareGum”) were developed in Dolatshahi-Pirouz’s research group , that acted as a component for a bionic glove to translate hand gestures into electronic signals to eventually help the rehabilitation of injured or deaf people. Most of the reported PPs based on SF are still in conflict with the anatomy and physiology of the human body in terms of mechanical properties and self-healing features .…”

Reconfigurable Magnetic Slime Robot: Deformation, Adaptability, and Multifunction

“…The water content (%) was calculated using the following equation [ 58 ] where W i is the initial weight of the slime before freeze drying and W d is the weight of the freeze‐dried slime.…”

Application of Silver-Loaded Halloysite Nanotubes in Flame Retardant and Smoke-Suppressive Coating for Polyester-Cotton Fabric

“…22 Hong et al 20 proposed the use of HNT-loaded silver nanoparticles for smoke suppression of epoxy resins. Inspired by mussels, Karolina Pierchala et al 23 designed a structure based on HNTs and polydopamine (PDA) as soft electronic materials. Abdullayev et al 24 first prepared silver acetate-loaded HNTs through a vacuum-outgassing cycle and then washed away the residue on the outer surface of HNTs, and finally silver acetateloaded HNTs were obtained at high temperature.…”