Fabrication and Characterization of Bimetallic Al-Ni Reactive Nanostructures as Nanoheaters

Heating is one of the most efficient and frequently used methods to alter material geometry, structure, and properties in both ancient and modern industries. Traditional macro- and micro-scale heating methods such as resistance and infrared heating have played a significant role in materials processing and manufacturing. However, with the continued miniaturization of electronics and devices, the expansion of multi-material systems, and the emergence of nanotechnologies, there is significant need for controlled and localized heating sources for thermal nanomanufacturing applications. There have been some methods under study to realize ultra-small heat spots with nanoscale dimensions, for example, nanoscale localized heating generated through a laser-heated AFM tip. However, most of the methods so far are serial, expensive, and difficult to scale-up.

In this presentation, we introduce a nanoscale heating source (“nanoheater”) based on an exothermic reaction between aluminum (Al) and nickel (Ni). The formation process of Al and Ni alloys is a good candidate for heat-generation purposes due to its large exothermic reaction enthalpies. The fabrication and characterization of various types of nanoheater structures, e.g., bi-metallic nanowires and core-shell nanoparticles, will be presented. These Ni-Al hetero- nanostructures are synthesized by either chemical or physical methods, and are characterized with SEM and TEM. Upon ignition using different methods such as electrical, magnetic field, or infrared heating, Ni-Al alloys are formed and one-time controlled and localized heat is generated from the exothermic reaction process. The potential applications of these nanoheaters in nanomaterial processing and biomedical field will also be discussed.