Shape memory alloys (SMAs) are innovative materials that allow a reversible martensitic phase transformation. They have a wide range of biomedical applications due to their pseudoelasticity and the ability to restore and retain a ‘memorized’ shape. In the biomedical industry, their macroscopic and microdevice properties offer a significant advantage in manufacturing components for microelectronic devices, including resistors, capacitors, and transistors. Furthermore, using biodegradable SMAs may enhance rehabilitation efficiency and decrease patients' discomfort compared to non-degradable SMAs. The development of nanocomposite shape memory alloys provides an additional benefit to the scientific community by overcoming the size limitations of traditional alloys. It thus opens new avenues for the use of nanoscaled biomedical devices. This chapter presents the latest findings and advancements in the mechanics and functionalization of nanotechnology-based shape memory alloys.