Biodegradable Implantable Sensors: Materials Design, Fabrication, and Applications

The ability to monitor diseases, therapies, and their effects on the body is a critical component of modern care and personalized medicine. Real time monitoring can be achieved by analyzing body fluids or by applying sensors on, or alternatively, inside the body. Implantable sensors, however, must be removed. Second removal procedures lead to further tissue damage, which can be a problem in tissues such as those of the central nervous system. The use of biodegradable sensors alleviates these problems since they do not require removal procedures. Recent advances in material science made it possible for all sensor components to be biodegradable. Small size and power of implants, and the limited selection of materials are the main constraints determining the capabilities of the biodegradable device. Thus, the design will be always a challenge exploring a trade‐off among these parameters. Despite of the encouraging results illustrating that biodegradable sensors can be as accurate and reliable as commercially available nondegradable ones, biodegradable implantable sensors are still in their infancy. Significant advances made in this area are critically reviewed in this paper, and future prospects are highlighted. Development of biodegradable implantable sensors enables real‐time and continuous monitoring of various parameters, and helps to obviate the need for sensor removal. Due to recent developments, it became possible to have all sensor components degradable and eliminable through natural body routes. So far, their functionality has been demonstrated in animals, and reports on clinical studies are awaited.