Perspective on the Next Generation of Injectable Probes Inspired by the History of Catheters’ Development

ABSTRACT Catheters have evolved from rigid 19th‐century tubes to sophisticated actuation‐capable systems, driven by clinical demands for precise navigation through tortuous vasculature, robust infection control in long‐term use, and multifunctionality across organ‐specific applications. Key reinforcements include magnetic actuation for enhanced steerability in neurointerventions, antimicrobial coatings like rifampin‐minocycline reducing bacteremia risks, and biocompatible soft polymers for improved flexibility and durability under physiological stresses. These advancements address challenges like sub‐millimeter accuracy (<1 mm diameters) in humans, minimizing trauma, and enabling high‐flow procedures. Such catheter‐inspired innovations have catalyzed the development of injectable probes featuring cellular‐scale dimensions (<100 µm) and multifunctional capabilities for neural interfacing, real‐time sensing, electrical stimulation, and targeted drug delivery in ultra‐minimally invasive therapies. This perspective reviews historical evolutions from ancient rudimentary tools to modern smart systems, organ‐specific classifications highlighting geometry adaptations, actuation mechanisms (tendon‐driven, pneumatic, hydraulic, electromechanical/magnetic), and material innovations, including shape‐memory alloys and hydrogel coatings for degradation mitigation. Future directions focus on AI (Artificial Intelligence)‐enabled wireless actuation, nanomaterials for personalized device geometries with >100% strain recovery, hybrid mechanisms, and bioinspired designs to achieve omnidirectional control and enhanced biocompatibility, thereby transforming precision medicine through advanced neuromodulation, stroke thrombolysis, and minimally invasive interventions.