## 1 Introduction  
Orthopedic implants are medical devices that are implanted surgically in the human body to replace missing joints and bones or restore the function of a damaged structure [1]. The market for orthopedic implants is one of the biggest in the medical field, and it is expected to expand significantly in the future, mainly due to the continuously growing elderly population. By taking hip replacement surgery as an example, more than 600,000 people need hip replacement surgery every year, and it is estimated that this number will exceed 1 million by 2030 [2, 3]. Until present, titanium alloys have been considered the gold standard choice for implant manufacturing, mainly due to their mechanical performance and excellent biocompatibility [4, 5, 6]. Despite this, the long-term use of titanium-based implants will result in the emergence of metal grinding particles, which would cause inflammation around the surrounding tissue, in addition to releasing metallic ions into the body. These inevitable phenomena can eventually lead to the failure of and require reoperation, which causes physical pain and financial burden to the patients [4, 7]. In this regard, zirconia (3Y-TZP) is a biomaterial that has been increasingly studied as a potential substitute for metal in biomedical implants, as shown in several studies [8, 9, 10, 11], such as the dental field [12, 13, 14, 15, 16], hip implants and knee prosthesis [17, 18]. The remarkable properties reported for 3Y-TZP in the literature include high flexural strength (up to 900-1200 MPa) [15], high fracture toughness (7-10 MPa m\({}^{1/2}\)) [14], wear resistance, optical and biological properties, biocompatibility and antibacterial properties [19, 20, 21]. Despite the efforts, the trend toward zirconia implants is still fraught with challenges, mainly due to its brittleness and sensitivity to surface defects. For this reason, good quality control during the manufacturing process is essential for the satisfactory long-term performance of zirconia implants, which raises the need for works focused on evaluating the optimal design for the next generation of zirconia implants. The ability to monitor the implant's performance along with its use in real time and establish communication with the user could offer advantages in detecting failures, transmitting qualitative data to start treatments and detecting eventual problems in advance. These achievements are only possible with the fabrication of implants endowed with smart implants, which are implantable devices (including sensors, actuators and antenna) that can provide therapeutic benefits and also diagnostic capabilities [22]. They offer a significant role in the patients' lives, covering various sensing and actuation applications in healthcare according to their external stimuli such as stress, light, temperature or magnetic fields [23; 24; 25; 26]. In the literature, there are some works reporting biomedical implants with smart devices coupled in their structure; however, in most cases, their size and adaptation along the implant structure can affect their properties negatively [27; 28; 29; 22]. Therefore, a manufacturing system capable of building, in one process, an orthomedical implant equipped with smart devices to make possible the analysis of issues in real-time in the implant and make decisions to perform smart actions is still a challenge to be overcome. In order to be accommodated in the implant, the communication module's antenna should be very small and require very low power, making its design a key requirement for an efficient antenna for the communication system [30; 31]. An exemplification of a hip implant endowed with smart components is illustrated in Figure 1.  
The conventional methods used to fabricate antennas in an insulator substrate may entail time-consuming and additional fabrication steps [31; 33]. However, resorting to additive manufacturing technology, it is possible to print implants with smart components, namely sensors, actuators and antennas, in a single step.