A comprehensive review of template-synthesized multi-component nanowires: From interfacial design to sensing and actuation applications

Abstract

Nanowires are one of the most promising nano-building blocks for many applications, including sensors/biosensors, electronics, photonics, energy conversion and storage devices, MEMS and NEMS, biotechnology and nanomedicine. With the growing demands of multi-purpose and multi-functional materials in these fields, different types of multi-component nanowires with complex structures have been designed and fabricated. Among various fabrication methods, porous anodic aluminum oxide (AAO) and polycarbonate (PC) membranes are well-established hard templates that have been used for synthesizing a variety of nanowires and nanowire structures. In this article, a comprehensive review of template-synthesized multi-component nanowire structures has been given, including multi-segmented, core-shell and multi-element nanowires, which can be synthesized by using these hard templates in a sequential or parallel way. Besides, the assembly and integration of different functions and properties into smaller and lighter devices require careful interfacial design and synthesis of multi-component nanowires. The interfacial structure and properties, such as interface uniformity, intermetallic compound formation and surface oxidation, have significant impact on the electrical and thermal conductivity, mechanical strength, functionality, stability and reliability of nanowire-based electronics and devices. A rational interfacial design is crucially important to improve these properties of nanowire devices for emerging multi-functional sensors and actuators, due in fact that sensors and actuators are among the most important components in many electronics and products. Multi-component nanowire based sensors and actuators have potential applications in a wide range of mechanical, electrical, thermal, and biomedical devices.