## 3 A Brief History of Prostheses  
Prostheses have a history that extends back thousands of years. Over the centuries, technological advances and material innovations have transformed prosthetics from simple mechanical replacements into highly sophisticated devices, such as modern robotic prosthetics. This progress has significantly improved the quality of life for individuals with physical disabilities, reflecting a gradual evolution from basic functionality to advanced systems that closely mimic natural movement and adaptability. Table 1 is a historical overview of prosthetic evolution, from early rudimentary models to contemporary innovations (the table is not a complete chronology; it is only a representation with some relevant examples). Early prosthetics, dating back to ancient civilizations, were crafted from basic materials like wood, metal, and leather, primarily aimed at restoring fundamental functionality. Contrary to the view that these devices served purely aesthetic purposes, historical records reveal practical applications. For instance, the iron hand of Roman General [PERSON] represents one of the earliest functional prosthetic devices specifically designed for combat, highlighting both its utility and symbolic importance [8]. Similarly, the discovery of an artificial toe on an Egyptian mummy, dating back to 950-710 B.C., Figure 1, illustrates early efforts to meet both functional and aesthetic needs in limb replacement [9]. These examples underscore that ancient prosthetics served purposes beyond appearance, demonstrating that designers valued usability alongside visual aspects. In the mid-20 th century, the first robotic prosthetics emerged, driven by a need to provide functional solutions for war veterans. These devices introduced electrically controlled mechanisms that enabled more complex movements. A significant milestone was reached in 1919 with the development of the first externally powered prosthesis, utilizing pneumatic and electric systems, thus marking a pivotal point in prosthetic innovation. However, these early robotic devices faced limitations, including high production costs, significant weight, and limited customization, which hindered widespread adoption. Despite being a breakthrough, early robotic prosthetics were often constructed from expensive materials and required complex manufacturing processes that did not adapt readily to individual anatomy, making them less practical for broader use [1]. During the 1970s and 1980s, advancements in materials science and electronics significantly improved the functionality, durability, and comfort of prosthetics (Figure 2). The introduction of lightweight materials, such as carbon fiber composites, not only enhanced the resilience of prosthetic devices but also made them more comfortable, thus better replicating the appearance and functionality of natural limbs. Recent advancements in bionic and myoelectric prosthetics have further enabled users to control artificial limbs through residual muscle signals, translating these signals into fluid, precise movements for enhanced daily functionality. Figure 1: (**a**) Egyptian toe prosthesis made of wood and leather, (**b**) iron leg prosthesis used by soldiers in the Crusades, (**c**) the “Voltaic Arm”, introduced by Sir [PERSON] [10]. The integration of 3D printing technology has also revolutionized the field, allowing for the rapid, cost-effective customization of prosthetics tailored to individual needs. Not only does 3D printing expedite production, but it also reduces costs, making advanced prosthetics more accessible. Concurrently, neural interface technology is advancing toward connecting prosthetic devices directly with the nervous system to provide sensory feedback. Although still in its developmental stages, this technology holds the potential to revolutionize prosthetics by allowing users to experience sensation through their devices, bringing them closer to full integration between humans and machines.