A novel multifunctional NiTi/Ag hierarchical composite

Abstract

Creating multifunctional materials is an eternal goal of mankind. As the properties of monolithic materials are necessary limited, one route to extending them is to create a composite by combining contrasting materials. The potential of this approach is neatly illustrated by the formation of nature materials where contrasting components are combined in sophisticated hierarchical designs. In this study, inspired by the hierarchical structure of the tendon, we fabricated a novel composite by subtly combining two contrasting components: NiTi shape-memory alloy and Ag. The composite exhibits simultaneously exceptional mechanical properties of high strength, good superelasticity and high mechanical damping, and remarkable functional properties of high electric conductivity, high visibility under fluoroscopy and excellent thermal-driven ability. All of these result from the effective-synergy between the NiTi and Ag components, and place the composite in a unique position in the properties chart of all known structural-functional materials providing new opportunities for innovative electrical, mechanical and biomedical applications. Furthermore, this work may open new avenues for designing and fabricating advanced multifunctional materials by subtly combining contrasting multi-components.

Brief Overview on Nitinol as Biomaterial

“…Silver is famous for its bacteria killing properties and coatings having silver addition are good against a number of bacteria [68] and there are some reports about NiTi-Ag shape memory alloys [62,69]. Researchers are working to improve the corrosion and biocompatibility of nitinol by three different ways: (1) addition of a third element in nitinol [34,62,69,70], (2) thin films formation on the surface of nitinol [58,71], and (3) nickel-free titanium based shape memory alloys [72][73][74].…”

Experimental and Finite Element Analysis of the Tensile Behavior of Architectured Cu-Al Composite Wires

“…Sapanathan et al [ 10 ] spiral extruded an aluminum/copper composite to study its bond strength and interfacial characteristics. Hao et al [ 11 ] developed a novel multifunctional NiTi/Ag hierarchical composite, inspired by the hierarchical design of the tendon, by repeated assembling and wire drawing. Tyson and Davies [ 12 ] investigated the shear stresses associated with stress transfer during fiber reinforcement with the help of photoelasticity.…”

Recoverable Wire-Shaped Supercapacitors with Ultrahigh Volumetric Energy Density for Multifunctional Portable and Wearable Electronics

“…By contrast, nickel–titanium alloy (NTA) as an electrode has been increasingly investigated in shape memory SCs due to its moderate phase-transition temperature (<40 °C). − Meanwhile, NTA exhibits higher elasticity/flexibility, better corrosion resistance, and better biocompatibility than conventional alloys. ,, Very recently, Liu et al successfully fabricated high performance planar SCs with body temperature inducible shape memory ability, in which graphene coated NTA flake was used as the negative electrode and ultrathin MnO 2 /Ni film was used as the positive electrode . Yang et al.…”